WBBSE Class 8 School Science Chapter 9 Endocrine System and Adolescence SAQs

WBBSE Chapter 9 Endocrine System And Adolescence Short Answer Type Questions

Question 1. What is adolescence?
Answer:

Adolescence:

Adolescence describes the teenage years between 13 and 19 and can be considered the transitional stage from childhood to adulthood.

However, the physical and psychological changes that occur in adolescence can start earlier, during the preteen years (ages 9 through 12)t Adolescence can be a time of both disorientation and discovery.

Question 2. Distinguish between the terms ‘puberty’ and ‘adolescence’.
Answer:

Distinguish between the terms ‘puberty’ and ‘adolescence’:

Puberty is the time in which a child’s sexual and physical characteristics mature. It occurs due to hormone changes.

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Short Answer Type Questions

Adolescence is the period between puberty and adulthood. Puberty is a period of physical transition; adolescence is about a psychological and social transition.

Puberty is the process of physical changes by which adolescents reach sexual maturity, i.e. become capable of reproduction.

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Question 3. How do hormones act in our bodies?
Answer:

Hormones act in our bodies:

Most hormones circulate in the blood, coming into contact with essentially all cells. However, a given hormone usually affects only a limited number of cells, which are called target cells. A target cell responds to a hormone because it bears receptors for the hormone.

  1. Estrogen
  2. Testosterone

Which of the two has a smaller voice box: grown-up boys or grown-up girls?
Grown-up girls.

Question 4. Mention a few feelings associated with adolescence.
Answer:

Fear, anger, crying, depression, offense, etc.

Question 5. What do you mean by emotion management?
Answer:

Emotion Management:

Emotion management refers to controlling the uncontrolled expression of happiness, anger, or sorrow which would otherwise affect our physical and mental health.

Follicle-stimulating hormone (FSH).

Locate and give one function of the following endocrine glands in man:

  1. Thyroid,
  2. Adrenal gland.

Thyroid: Location—On either side of the upper border of the trachea, just below the larynx.

Function—It secretes thyroxine which increases BMR by stimulating the metabolism of carbohydrates, fat, and protein in the body.

Adrenal gland: Location-On the upper pole of each kidney.

Function—It secretes corticoid and catecholamine hormones which control the metabolism of carbohydrates, protein, fat, mineral, and water and also help to fight against stress.

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Question 6. Name the hormones secreted by the posterior pituitary.
Answer:

  1. Antidiuretic hormone (ADH) or Vasopressin and
  2. Oxytocin.

Question 7. Name two hormones secreted by the anterior pituitary gland in man.
Answer:

  1. ACTH or Adrenocorticotrophic hormone
  2. TSH or Thyroid stimulating hormone.

Question 8. 1. What is glucagon? 2. From which gland and which cells is it secreted? 3. What is its function?
Answer:

Glucagon:

  1. Glucagon is a polypeptide hormone.
  2. It is secreted from the pancreas gland.
  3. Functions of glucagon—
  4. It stimulates glycogenolysis in the liver to add glucose to blood i.e., it increases blood sugar levels,
  5. It stimulates neo-glucogenesis in the liver to convert amino acids to glucose and glycogen.

Question 9. 1. What do you mean by master gland? 2. Where is it situated in the human body? 3. Mention the different parts, 4. Name two trophic animal hormones.
Answer:

Master gland:

  1. The master gland means the pituitary gland.
  2. It is situated at the base of the brain, within a cup-shaped cavity of sphenoid bone called sella turcica.
  3. The pituitary gland has two main parts—
  4. anterior pituitary
  5. posterior pituitary
  6. Adrenocorticotropic hormone (ACTH), Thyroid stimulating hormone (TSH).

Chapter 9 Endocrine System and Adolescence Short Answer Questions

Question 10. Name a hormone secreted by each of the glands adrenal, testis, and ovaries, and mention one important function of each of these hormones.
Answer:

Adrenaline—It increases the metabolic rate of the body. Testis—Its hormone is testosterone which causes the growth of accessory sex organs and the development of secondary sex characteristics in males.

Ovary—It’s one hormone is estrogen which causes the growth of accessory sex organs and the development of secondary sex characteristics in females.

Question 11. What is diabetes mellitus?
Answer:

Diabetes Mellitus:

A disorder in which the body’s cells cannot absorb glucose, either because the pancreas does not produce enough insulin or the cells do not respond to the effects of insulin that are produced in the body.

Question 12. Which hormone is called emergency hormone and why?
Answer:

The adrenal medullary hormone adrenaline is called emergency hormone because it helps the body fight against (or adjust to) emergency conditions by increasing circulation and respiration along with the activity of skeletal muscles, eyes, etc.

WBBSE Class 8 School Science Chapter 9 Endocrine System and Adolescence SAQs

Question 13. Differentiate between Exocrine Gland and Endocrine Glands.
Answer:

Differentiate between Exocrine Gland and Endocrine Gland:

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence exocrine glands and endorine glands

WBBSE Class 8 Science Important Short Answers

Question 14. Differentiate between Anterior Pituitary and Posterior Pituitary.
Answer:

Differentiate between Anterior Pituitary and Posterior Pituitary:

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Anterior pituitary,posterior pitutary

WBBSE Class 8 Science Short Answer Format

Question 15. Which hormones are responsible for the changes in human bodies in the adolescent period?
Answer:

The rise in the level of sex hormones is responsible for the changes in the bodies of adolescent boys and girls at puberty.

The tastes make the male sex hormones called testosterone. The ovaries make female sex hormones called estrogen. The production of these sex hormones is under the control of another hormone called gonadotropic hormone (GTH) secreted by the pituitary gland.

Question 16. People are advised to use iodized salt for cooking food so as to prevent goiter disease- why?
Answer:

People are advised to use iodized salt for cooking food so as to prevent goiter disease:

The thyroid gland needs a constant supply of iodine in order to produce thyroxine hormone. This iodine normally comes from the diet we eat.

Since iodine is necessary for the making of thyroxine hormone, therefore, a deficiency of iodine in the diet can cause a deficiency of thyroxine hormone in the body.

The deficiency of thyroxine causes a disease known as goiter. Iodized salt can provide all the iodine needed by the thyroid gland to make sufficient thyroxine hormone for our body. Hence iodized salt prevents goiter disease.

WBBSE Class 8 Science Practice Questions on Endocrine System

Question 17. Gland G is located just below the stomach in the human body.
Answer:

It is a mixed gland that secretes the hormone H.

The deficiency of hormone H in the body causes a disease D in which the blood sugar level of a person rises too much. What are G, H, and D?

Gland G is the pancreas which is a mixed (heterochrony) gland. Pancreas secretes hormone H called insulin. A deficiency of insulin leads to disease D known as Diabetes mellitus.

Question 18. Name the hormones which are responsible for the following symptoms:
Answer:

  1. Unnatural growth of body, growth of bones.
  2. The face becomes rounded by swelling, skin becomes rough and pale, and wounds take more time to heal.
  3. Swelling of glands, eyes bulge out, body temperature increases.
  4. Gigantism: Hypersecretion of growth hormone (GH).
  5. Cushing syndrome: Hypersecretion of corticosteroids.
  6. Goiter: Hypersecretion of thyroxine.

Short Answer Resources for Class 8 Endocrine System

Question 19. Mention the problem associated with the adolescence stage. What are the steps of problem-solving?
Answer:

The problems of the adolescence stage are:

  1. sex problem
  2. emotional problem

social problem including drug abuse Problem solving incorporates the identification of the root cause of the problem and searching for a suitable way to overcome it.

Four basic steps in problem-solving are:

  1. Defining problems
  2. Brainstorming about alternatives
  3. Evaluating and selecting the best alternative
  4. Implementation of solution.

WBBSE Class 8 School Science Chapter 9 Endocrine System and Adolescence VSAQs

Chapter 9 Endocrine System And Adolescence VSAQs

Question 1. What is adolescence?
Answer:

Adolescence:

Adolescence describes the teenage years between 13 and 19 and can be considered the transitional stage from childhood to adulthood.

Question 2. Write the origin of the word ‘adolescence’.
Answer:

The word ‘adolescence’ comes from the Latin word ‘adolescence’ which means ‘to grow’.

Question 3. What is puberty?
Answer:

Puberty:

Puberty is the time in which a child’s sexual and physical characteristics mature.

Question 4. What is the main reason behind puberty?
Answer:

Main Reason behind puberty:

During puberty, various endocrine glands produce hormones that cause body changes and the development of secondary sex characteristics.

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Very Short Answer Type Questions

WBBSE Class 8 Very Short Answer Questions Endocrine System

Question 5. What are hormones?
Answer:

Hormones:

Hormones are chemical messengers secreted into the blood or extracellular fluid by one cell that affect the functioning of other cells.

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Question 6. What is meant by target cells of hormones?
Answer:

Target cells of hormones:

A given hormone usually affects only a limited number of cells, which are called target cells.

Question 7. How does a target cell response to a hormone?
Answer:

A target cell responds to a hormone because it bears receptors for the hormone.

Question 8. What are endocrine glands?
Answer:

Endocrine glands:

Glands that do not have tubes. They secrete hormones. Example- the pituitary gland.

Question 9. What are exocrine glands?
Answer:

Exocrine glands:

Glands that have ducts are called exocrine glands. They generally secrete enzymes. Example- salivary gland.

Chapter 9 Endocrine System and Adolescence WBBSE Answers

Question 10. Why endocrine responses are generally slow?
Answer:

Endocrine responses are slow because hormones must travel through the blood to reach their target organs.

Question 11. Name two mixed glands, other than the pancreas.
Answer:

Testes and ovaries are mixed glands.

Question 12. Which endocrine gland is situated above the kidney?
Answer:

Adrenal (Hence it is also known as supra renal gland).

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Question 13. Which hormone has iodine as its component?
Answer:

Thyroxin

Question 14. Deficiency of which hormone causes diabetes insipid?
Answer:

Antidiuretic hormone or ADH.

Question 15. Deficiency of which hormone causes diabetes mellitus?
Answer:

Insulin.

Question 16. Which endocrine gland is considered a master gland?
Answer:

Pituitary.

Question 17. Deficiency of which hormone causes cretinism?
Answer:

Thyroxin.

WBBSE Class 8 Science Very Short Answer Format

Question 18. Deficiency of which hormone causes dwarfism?
Answer:

Somatotrophic hormone or STH.

Question 19. Excess of which hormone causes gigantism?
Answer:

Somatotrophic hormone or STH.

Question 20. Hyper-function of which hormone causes exophthalmic goiter?
Answer:

Thyroxin.

Question 21. Which hormone stimulates the adrenal gland?
Answer:

ACTH.

Question 22. Which hormone stimulates the thyroid gland?
Answer:

TSH.

Question 23. Name a hormone produced by the testes.
Answer:

Testosterone.

Question 24. Which hormone helps in the regulation of blood pressure?
Answer:

Vasopressin.

WBBSE Class 8 Science Important Very Short Answers

Question 25. Deficiency of which hormone causes an increase in blood glucose level?
Answer:

Insulin.

Question 26. Name the hormone antagonistic to insulin.
Answer:

Glucagon.

Question 27. What is hyperglycemia?
Answer:

Hyperglycemia:

Increase in blood glucose level.

Question 28. Name a local hormone.
Answer:

Gastrin, secreted from the stomach.

Question 29. Which hormone helps in milk secretion?
Answer:

Prolactin.

Question 30. Name two steroid hormones.
Answer:

Estrogen and progesterone.

Question 31. What is the other name for pituitary?
Answer:

Hypophysis.

Very Short Answer Questions for Class 8 Endocrine System

Question 32. What causes tetany?
Answer:

Tetany:

Deficiency of parathormone.

Question 33. Which endocrine gland produces gonadotrophic hormones?
Answer:

Anterior part of the pituitary.

Question 34. Which hormone is considered an emergency hormone?
Answer:

Adrenalin.

Question 35. What causes pimples and acne?
Answer:

Hormonal changes.

Question 36. State a symptom of fear.
Answer:

Palpitation.

Question 37. Which education helps in decision-making, critical thinking, etc?
Answer:

Skill education.

Question 38. What is emotion management?
Answer:

Emotion management:

Identifying our emotions and learning to express them.

Question 39. Name the smallest endocrine gland of the human body.
Answer:

Pineal body is attached to the roof of the third ventricle of the brain.

WBBSE Class 8 Science Study Guide Endocrine System

Question 40. What do you mean by life skill education?
Answer:

Life skill education is a special behavior that helps us to face various needs and challenges boldly.

Question 41. Name the hormone which develops secondary sexual characteristics :
Answer:

  1. In females (girls)
  2. In males (boys)
  3. Estrogen
  4. Testosterone

Question 42. Which of the two has a smaller voice box: grown-up boys or grown-up girls?
Answer:

Grown-up girls.

Question 43. Mention a few feelings associated with adolescence.
Answer:

Fear, anger, crying, depression, offense, etc.

Endocrine System and Adolescence WBBSE Resources

Question 44. What do you mean by emotion management?
Answer:

Emotion Management:

Emotion management refers to controlling the uncontrolled expression of happiness, anger, or sorrow which would otherwise affect our physical and mental health.

Question 45. Mention a few examples of risky behaviors associated with the adolescent period.
Answer:

Uncontrolled burning of crackers Excessive honking Drug addiction etc.

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Review Questions

Chapter 9 Endocrine System And Adolescence Review Questions MCQs

Question 1. Along with the nervous system, the system coordinates the various activities of body parts.

  1. Digestive
  2. Endocrine
  3. Circulatory
  4. Excretory

Answer: 2. Digestive

Question 2. These are chemical messengers that are produced in one body region but affect a different body region.

  1. Hormones
  2. Enzymes
  3. Endocrines
  4. Vitamines

Answer: 1. Hormones

Question 3. Hormones are substances that fall into two basic categories.

  1. Proteins and sugars
  2. Male hormones and female hormones
  3. Non-steroid and steroid hormones.
  4. Organic and inorganic

Answer: 3. Non-steroid and steroid hormones.

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Review Questions

Question 4. The hypothalamus regulates

  1. Heart rate
  2. Body temperature
  3. Both 1 and 2 correct
  4. None of 1 and 2 are correct

Answer: 3. Both 1 and 2 correct

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Question 5. The posterior pituitary secretes

  1. Adh and oxytocin
  2. Estrogen and testosterone
  3. Adrenalin and insulin
  4. Epinephrine and norepinephrine

Answer: 1. Estrogen and testosterone

Question 6. The function(s) of oxytocin is/are to

  1. Cause the uterus to contract
  2. Induce labor
  3. Both and correct
  4. None of and are correct

Answer: 3. Induce labor

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Question 7. Hypothalamic releasing and release-inhibiting hormones are transported from the hypothalamus to the anterior pituitary by the way of

  1. The general bloodstream
  2. A portal system of blood vessels directly connecting the two organs
  3. Direct contact between the two organs
  4. Nervous system

Answer: 2. A portal system of blood vessels directly connecting the two organs

Question 8. Hormones produced by the anterior pituitary that have a direct effect on the body, rather than trigger another gland, are

  1. Tsh, acth, and gonadotropic hormones
  2. Gh, prolactin and msh
  3. Testosterone and estrogen
  4. Sth and lh

Answer: 2. Gh, prolactin and msh

Question 9. Gh does not promote.

  1. Fatigue
  2. Cell division
  3. Protein synthesis
  4. Lipid metabolism

Answer: 1. Fatigue

Question 10. Which hormone dramatically affects physical appearance?

  1. Gonadotropin-releasing hormone
  2. Growth
  3. Steroid
  4. None of these

Answer: 2. Growth

Question 11. In humans, msh (melanocyte-stimulating hormone).

  1. Regulates primary skin color
  2. Causes the thyroid to produce thyroxin
  3. Concentration is very low
  4. Is not found

Answer: 2. Causes the thyroid to produce thyroxin

Chapter 9 Endocrine System and Adolescence WBBSE Solutions

Question 12. An overproduction in adults causes a condition called.

  1. Hyperthyroidism
  2. Acromegaly
  3. A pituitary giant
  4. Diabetes

Answer: 3. A pituitary giant

Question 13. The parathyroid glands are located

  1. Below the thyroid, hence the name “para”
  2. Above the thyroid, hence the name “para”
  3. Embedded in the posterior surface of the thyroid gland
  4. Infront of thyroid

Answer: 3. Embedded in the posterior surface of the thyroid gland

Question 14. It is lacking in the diet, and the thyroid gland enlarges, producing goiter.

  1. Thyroxin
  2. Iodine
  3. Iron
  4. Vitamin c

Answer: 2. Iodine

Question 15. If the thyroid fails to develop properly from childhood, a condition called results.

  1. Goiter
  2. Poly dips
  3. Acromegaly
  4. Cretinism

Answer: 4. Cretinism

Question 16. Hypothyroidism in adults produces a condition called.

  1. Myxedema
  2. Goiter
  3. Acromegaly
  4. Cretinism

Answer: 1. Myxedema

Question 17. In addition to thyroxine and triiodothyronine, the thyroid gland produces

  1. Tsh
  2. Acth
  3. Calcitonin
  4. Gluco corticoid

Answer: 3. Calcitonin

Question 18. If the insufficient path is produced, the blood calcium level drops, resulting in

  1. Reduced growth in childhood or parathyroid dwarfism
  2. Tetany, where the body shakes from continuous muscle contraction
  3. Exophthalmic goiter
  4. Virilism

Answer: 2. Tetany, where the body shakes from continuous muscle contraction

WBBSE Class 8 Science Important Review Questions

Question 19. The adrenal glands consist of

  1. The inner and outer layers of the kidney
  2. The inner cortex and the outer medulla
  3. Lower adrenal and upper pararenal sections
  4. The inner medulla and the outer cortex

Answer: 4. The inner medulla and the outer cortex

Question 20. The adrenal medulla secretes under conditions of stress.

  1. Norepinephrine
  2. Epinephrine
  3. Norepinephrine and epinephrine
  4. Aldosterone

Answer: 3. Norepinephrine and epinephrine

Question 21. Which one of the following is an endocrine gland?

  1. Salivary
  2. Sweat
  3. Mammary
  4. Parathyroid

Answer: 4. Parathyroid

Question 22. Acth controls the secretion of

  1. Cortisol
  2. Aldosterone
  3. Epinephrine
  4. Oxytocin

Answer: 1. Cortisol

Question 23. Low levels of adrenal cortex hormones result in

  1. Addison disease
  2. Cushing syndrome
  3. Diabetes
  4. Virilism

Answer: 1. Addison’s disease

Question 24. A person with Addison’s disease

  1. Is unable to replenish blood glucose levels under stressful conditions
  2. Develops dramatically more male features
  3. Develops a rounded face and edema
  4. Develops lethargy and coma

Answer: 1. Is unable to replenish blood glucose levels under stressful conditions

Question 25. In the blood, hormones are present in the form of

  1. Polymer
  2. Dimer
  3. Monomer
  4. All of these

Answer: 4. All of these

Review Questions for Class 8 Endocrine System

Question 26. The pancreatic islets produce

  1. Insulin and glucagon
  2. Pancreatin
  3. Acth and aldosterone
  4. Adh and lh

Answer: 1. Insulin and glucagon

Question 27. Insulin functions too.

  1. Promote the storage of nutrients
  2. Lower the blood glucose level by stimulating liver, fat, and muscle cells to metabolize glucose
  3. Stimulate uptake of glucose by cells
  4. Promote the transformation of liver glycogen into glucose

Answer: 3. Stimulate uptake of glucose by cells

Question 28. In diabetes, the pancreas is not producing insulin.

  1. Type I
  2. Type ii
  3. Type iii
  4. None of these

Answer: 1. Type I

Question 29. These are the male sex hormones.

  1. Progesterone
  2. Estrogens
  3. Aldosterones
  4. Androgens

Answer: 4. Androgens

Question 30. Hormones are released by

  1. Endocrine glands
  2. Heterocrine glands
  3. Apocrine glands
  4. Both 1 and 2

Answer: 4. Both 1 and 2

Endocrine System and Adolescence WBBSE Study Guide

Question 31. The produces the hormone melatonin.

  1. Pituitary gland
  2. Pineal gland
  3. Thyroid gland
  4. Parathyroid gland

Answer: 2. Pineal gland

Question 32. When a hormone name ends in “tropic,” what does this mean?

  1. The hormone stimulates the metabolism of the cell it contacts
  2. It means the hormone affects another “target” endocrine gland
  3. It means it is a posterior pituitary hormone
  4. The hormone is self-destructive in nature

Answer: 2. It means the hormone affects another “target” endocrine gland

Question 33. Which endocrine glands are stimulated?

  1. Thyroid
  2. Testes/ovaries
  3. Adrenal medulla
  4. Pituitary

Answer: 2. Testes/ovaries

Question 34. Exophthalmos of the eyes is a characteristic sign of

  1. Myxedema
  2. Cretinism
  3. Graves’ disease
  4. Dwarfism

Answer: 3. Graves’ disease

Question 35. A “moon face,” and heavy fat deposition over the scapula, “buffalo hump” suggests that a person has chronically high levels of

  1. Insulin
  2. Gh
  3. Cortisol
  4. Epinephrine

Answer: 3. Cortisol

Question 36. The development of primary sex characteristics is evidenced by

  1. A rapid change in height and weight
  2. Growth and development of the ovaries
  3. Growth and development of the breasts
  4. Modulation of voice

Answer: 3. Growth and development of the breasts

Question 37. As opposed to primary sexual characteristics, changes in secondary sexual characteristics are mostly evident changes in

  1. Reproductive capacity
  2. The skeletal system
  3. External appearance
  4. Endocrine system

Answer: 3. External appearance

Question 38. If an adolescent was exposed to an external stimulus that artificially raised the level of sex hormones in the body, how would the hypothalamus likely to respond?

  1. By changing the instructions it sends to the pituitary gland
  2. By altering the instructions it sends to the gonads
  3. By ignoring the artificial levels of sex hormones in the body
  4. Becoming dormant

Answer: 1. By changing the instructions it sends to the pituitary gland

Question 39. When an adolescent’s facial hair starts growing, or acne develops, or breasts start to grow, or the genitals start to change, which organ in the body are these changes directly caused by?

  1. The hypothalamus
  2. The adrenal glands
  3. The brain
  4. The ovaries or testicles

Answer: 4. The ovaries or testicles

Question 40. A man suddenly sees a tiger. His heart beat goes up, his blood pressure increases, etc. Which hormone is released at this time in the body?

  1. Corticoid
  2. Parathormone
  3. Adrenaline
  4. Thyroxine

Answer: 2. Parathormone

Question 41. Muscle growth during puberty occurs

  1. Only in males
  2. Only in females
  3. In both genders
  4. In none of the genders

Answer: 1. Only in males

Chapter 9 Endocrine System WBBSE Resources

Question 42. A late development in the pubertal sequence of females is

  1. Breast development
  2. Growth of pubic hair
  3. Menarche
  4. Oogenesis

Answer: 3. Menarche

Question 43. The possible causes of eating disorders among adolescents include all of the following except

  1. Lack of control over attractions to certain food
  2. Genetic predispositions
  3. Family dysfunction
  4. All of these

Answer: 1. Lack of control over attractions to certain food

Question 44. Which of the following endocrine glands does 49? Not occur as a pair in the human body?

  1. Adrenal
  2. Pituitary
  3. Testis
  4. Ovary

Answer: 2. Pituitary

Question 45. While adolescence is naturally a very healthy 50. Period of life, many adolescents experience health problems due to

  1. Genetic defects
  2. Hormonal dysfunction
  3. Lifestyle choices
  4. Immature brain development

Answer: 3. Lifestyle choices

Question 46. Which group of adolescents evidence the highest rates of drug and alcohol use in early adolescence?

  1. Late maturing males
  2. Average maturing males
  3. Early maturing males
  4. None of these

Answer: 3. Early-maturing males

Question 47. Which one is a mixed gland?

  1. Kidney
  2. Thyroid
  3. Sweat
  4. Pancreas

Answer: 4. Pancreas

Question 48. Which hormone(s) is/are known as the fright and flight hormone?

  1. Adrenaline and nor-adrenaline
  2. Oxytocin and vasopressin
  3. Tsh and acth
  4. Insulin and glucagon

Answer: 1. Adrenaline and nor-adrenaline

Question 49. The chemical structure of a hormone enables it to combine with a receptor in the cells of its

  1. Target
  2. Gland
  3. Organ
  4. All of these

Answer: 1. Target

Question 50. Life skill education is needed for

  1. Early identification and intervention of problem
  2. Development of psycho-social capacity
  3. Building self-image
  4. All of these

Answer: 4. All of these

 

Chapter 9 Endocrine System And Adolescence Fill In The Blanks

Question 1. Acromegaly and gigantism are the results of _________ of growth hormone.
Answer: Hypersecretion

Question 2. The largest pure endocrine gland in the body is the _________.
Answer: Thyroid

Question 3. Alpha islet cells of the pancreas produce _________, an extremely potent hyperglycemic hormone.
Answer: Glucagon

Question 4. The _________ gland may influence our day/ night cycles and even regulate the onset of sexual maturity.
Answer: Pineal

Question 5. The _________ gland is especially large in early childhood; then declines in size and function with age.
Answer: Thymus

Question 6. Hypersecretion of growth hormone after epiphyseal plate closure can result in a condition called _________
Answer: Acromegaly

Question 7. As a result of stress the adenohypophysis releases which stimulates the release of hormones from the adrenal _________ cortex that retain sodium and water, increase blood sugar and begin breaking down fats.
Answer: ACTH

Question 8. _________ describes the teenage years between 13 and 19 and can be considered the transitional stage from childhood to adulthood.
Answer: Adolescence

Question 9. The word ‘adolescence’ comes from the Latin word _________ which means ‘to grow’.
Answer: Adolescere

Question 10. _________ is the time in which a child’s sexual and physical characteristics mature.
Answer: Puberty

Question 11. During puberty, various endocrine glands produce _________ that cause body changes
and the development of secondary sex characteristics.
Answer: Hormones

Question 12. Hormones are _________ messengers secreted into the blood.
Answer: Chemical

Question 13. A given hormone usually affects only a _________ limited number of cells, which are called cells.
Answer: Target

Question 14. A target cell responds to a hormone because it bears _________ for the hormone.
Answer: Receptors

Question 15. The endocrine system is composed of _________ glands.
Answer: Ductless

Question 16. Nerve cells in the control the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary.
Answer: Hypothalamus

Question 17. The pituitary is often called the _________ because it makes hormones that control several other endocrine glands.
Answer: Master gland

Question 18. The tiny _________ gland is divided into two parts: the anterior lobe and the posterior lobe.
Answer: Pituitary

Question 19. _________ is referred to as vasopressin, this hormone helps to regulate water balance in the body.
Answer: ADH

Question 20. _________ gland secretes melatonin, a hormone that may help regulate the wake-sleep cycle.
Answer: Pineal

Question 21. The _________ located in the front part of the lower neck, is shaped like a bow tie or butterfly and produces the thyroid hormones thyroxine and triiodothyronine.
Answer: Thyroid

Question 22. The body has two triangular adrenal glands, one on top of each _________.
Answer: Kindly

Question 23. The inner part, the _________ produces catecholamines, such as epinephrine.
Answer: Adrenal medulla

Question 24. The pancreas produces two important hormones, insulin and _________.
Answer: Glucagon

Question 25. The _________ are the main source of sex hormones.
Answer: Gonads

Question 26. The female gonads, _________ are located in the pelvis.
Answer: Ovaries

Question 27. _________ is a disorder in which the anterior pituitary produces too much growth hormone (GH).
Answer: Acromegaly

Question 28. _________ is an autoimmune disorder in which specific antibodies produced by the immune system stimulate the thyroid gland to become overactive.
Answer: Graves’ diseases

Question 29. Diabetes _________ is a disorder in which the body’s cells cannot absorb glucose, either because the pancreas does not produce enough insulin or the cells do not respond to the effects of insulin that are produced.
Answer: Mellitus

Question 30. Excessive amounts of glucocorticoid hormones in the body can lead to _________ syndrome.
Answer: Cushing

Question 31. Who identifies _________ as the period in human growth and development that occurs after childhood and before adulthood, from ages 10 to l9.
Answer: Adolescence

WBBSE Class 8 Science Practice Questions on Endocrine System

Question 32. Adolescence is a time of rapid change and many challenges as young people transition from childhood to _________.
Answer: Adulthood

Question 33. _________ adolescence extends roughly from 12/13 to 16 / 17 years.
Answer: Early

Question 34. _________ adolescence covers the period from 17 years to 18 / 19 years.
Answer: Late

Chapter 9 Endocrine System And Adolescence Match the Column

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence match the column
Answer: A-5,B-6,C-4,D-3,E-1,F-2

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence match the column.2

 

 

 


Answer:
A-4,B-1,C-5,D-3,E-2

WBBSE Notes For Class 8 School Science Chapter 9 Endocrine System And Adolescence

Chapter 9 Endocrine System and Adolescence

Introduction

The word ‘adolescence’ comes from the Latin word ‘adolescence’ which means ‘to grow’. Adolescence describes the teenage years between 13 and 19 and can be considered the transitional stage from childhood to adulthood.

However, the physical and psychological changes that occur in adolescence can start earlier, during the preteen years (ages 9 through 12).

Adolescence can be a time of both disorientation and discovery. The transitional period can bring up issues of independence and self-identity.

Physiological changes in adolescence:

  1. Enhanced growth and development
  2. Changes in attitude, appearance, and personality

Hormonal changes inside the body Behavioural changes in adolescence:

  1. Enhancement of thinking ability encompassing future thinking.
  2. Sharing of social responsibilities
  3. Actions are mostly driven by ideas but not reasons.
  4. Transitioning from one period to another always is associated with some problems. Adolescence is not an exception and it is also associated with some problems.

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Puberty and Adolescence

Puberty is the time in which a child’s sexual and physical characteristics mature. It occurs due to hormone changes. Adolescence is the period between puberty and adulthood.

Puberty is a period of physical transition; adolescence is about a psychological and social transition. Puberty is the process of physical changes by which adolescents reach sexual maturity, i.e., become capable of reproduction.

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Puberty and adolescence

WBBSE Class 8 Endocrine System notes

The various changes which occur in boys during puberty:

  1. Growth of hair on face and chest.
  2. Deepening of voice
  3. Spermatogenesis starts
  4. The body becomes muscular with the rapid increase in height.
  5. Feelings and sexual drives associated with adulthood begin to develop.

The various changes which occur in girls during puberty:

  1. Breasts develop and enlarge
  2. Ovulation and menstruation start
  3. Hips become wider.
  4. An increase in height occurs
  5. Feelings and sexual drives associated with adulthood begin to develop.

WBBSE Notes For Class 8 School Science Chapter 8 Human Food And Food Production

Hormones and Endocrine Glands

What exactly are hormones and how are they different from “non-hormones”? Hormones are chemical messengers secreted into the blood or extracellular fluid by one cell that affect the functioning of other cells.

Most hormones circulate in the blood, coming into contact with essentially all cells. However, a given hormone usually affects only a limited number of cells, which are called target cells. A target cell responds to a hormone because it bears receptors for the hormone.

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Hormones and endocrine glands

 

What is a gland? A gland is an organ in the human or animal body that secretes hormones or chemical discharge internally or externally for different body activities.

There are two types of glands in our body:

  1. Endocrine gland
  2. Exocrine gland.

Glands that do not have any ducts or tubes are called endocrine glands. Endocrine glands secrete hormones, which are chemical “messengers” that travel through the blood to regulate the activity of a target organ.

Examples: Pituitary gland, Thyroid gland, Adrenal gland, etc.

Glands that have ducts are called exocrine glands. The secretions of exocrine glands reach their target by traveling through a duct (tube).

Exocrine glands are not part of the endocrine system. Some examples of exocrine glands are sweat glands and salivary glands. There are some glands that are both endocrine and exocrine in nature. These are called mixed glands.

Pancreas is a mixed gland. The endocrine part secretes major hormones of the body and the exocrine part creates pancreatic enzymes which are needed for digestion.

Endocrine System

The foundations of the endocrine system are the hormones and glands. As the body’s chemical messengers, hormones transfer information and instructions from one set of cells to another.

Although many different hormones circulate throughout the bloodstream, each one affects only the cells that are genetically programmed to receive and respond to its message.

Endocrine glands and their functions for Class 8

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Secretory gland hormone

Understanding adolescence and hormones for Class 8

Hormone levels can be influenced by factors such as stress, infection, and changes in the balance of fluid and minerals in the blood.

The major glands that make up the human endocrine system are the hypothalamus, pituitary, thyroid, parathyroids, adrenals, pineal body, and reproductive glands.

The pancreas is also part of this hormone-secreting system, even though it is also associated with the digestive system because it also produces and secretes digestive enzymes.

 

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence endocrine system

 

Although the endocrine glands are the body’s main hormone producers, some non-endocrine organs — such as the brain, heart, lungs, kidneys, growth and the development of the brain and liver, thymus, skin, and placenta — also produce and release hormones.

Hypothalamus

The hypothalamus, a collection of specialized cells that are located in the lower central part of the brain, is the primary link between the endocrine and nervous systems.

Nerve cells in the hypothalamus control the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary.

Pituitary Gland

Although it is no bigger than a pea, the pituitary gland, located at the base of the brain just beneath the hypothalamus, is considered the most important part of the endocrine system.

It’s often called the “master gland” because it makes hormones that control several other endocrine glands.
The production and secretion of pituitary hormones can be influenced by factors such as emotions and seasonal changes.

To accomplish this, the hypothalamus relays information sensed by the brain (such as environmental temperature, light exposure patterns, and feelings) to the pituitary.

The tiny pituitary gland is divided into two lobes: the anterior lobe and the posterior lobe.
The anterior lobe regulates the activity of the thyroid, adrenals, and reproductive glands. Among the hormones it produces are:

  1. Growth hormone,
  2. Prolactin
  3. Adrenocorticotropic hormone (ACTH),
  4. Thyroid-stimulating hormone (TSH),
  5. Luteinizing hormone (LH),
  6. Follicle-stimulating hormone (FSH).

The other lobe of the pituitary gland is called the posterior pituitary which controls different physiological functions of the body, it produces the following two hormones:

  1. Oxytocin,
  2. Antidiuretic hormone (ADH) or vasopressin.

The pituitary also secretes endorphins, chemicals that act on the nervous system to reduce sensitivity to pain. In addition, the pituitary secretes hormones that signal the ovaries and testes to make sex hormones. The pituitary gland also controls ovulation and the menstrual cycle in women.

The posterior lobe of the pituitary releases antidiuretic hormone, which helps control body water balance through its effect on the kidneys and urine output; and oxytocin, which triggers the contractions of the uterus that occur during labor.

Pineal Gland

The pineal body, also called the pineal gland, is located in the middle of the brain. It secretes melatonin, a hormone that may help regulate the wake-sleep cycle.

Thyroid and Parathyroids

The thyroid, located in the front part of the lower neck, is shaped like a bow tie or butterfly and produces the thyroid hormones thyroxine and triiodothyronine.

These hormones control the rate at which cells burn fuels from food to produce energy. As the level of thyroid hormones increases in the bloodstream, so does the speed at which chemical reactions occur in the body.

Thyroid hormones also play a key role in the bone nervous system in children. The production and release of thyroid hormones is controlled by thyrotropin, which is secreted by the pituitary gland.

Attached to the thyroid are four tiny glands that function together called the parathyroids. They release parathyroid hormone, which regulates the level of calcium in the blood with the help of calcitonin, which is produced in the thyroid.

Adrenal Glands

The body has two triangular adrenal glands, one on top of each kidney. The adrenal glands have two parts, each of which produces a set of hormones and have a different function.

The outer part, the adrenal cortex, produces hormones called corticosteroids that influence or regulate salt and water balance in the body, the body’s response to stress, metabolism, the immune system, and sexual development and function.

The inner part, the adrenal medulla, produces catecholamines, such as epinephrine, also called adrenaline.
Adrenaline is a hormone secreted by the adrenal medulla during stress.

WBBSE Chapter 9 summary on endocrine system

This is called emergency growth of facial and pubic hair, and hormones because it initiates a quick reaction that makes the individual think and respond quickly to stress.

The hormone increases metabolic rate. There occurs dilatation of blood vessels going to the heart and the brain. The blood vessels reaching the skin and kidneys constrict in order to provide more blood to the heart and the brain.

They also increase fat metabolism thereby synthesizing more energy. The word adrenaline is used in common parlance to denote increased activation of the sympathetic system associated with the energy and excitement of the fight-or-flight response.

Pancreas

The pancreas produces (in addition to others) two important hormones, insulin, and glucagon. They work together to maintain a steady level of glucose, or sugar, in the blood and to keep the body supplied with fuel to produce and maintain stores of energy.

Gonads or Reproductive Glands

The gonads are the main source of sex hormones. In males, they are located in the scrotum. Male gonads, or testes, secrete hormones called androgens, the most important of which is testosterone.

These hormones regulate body changes associated with sexual development and the appearance of other male secondary sex characteristics such as the deepening of the voice and the increase in muscle growth and strength.

The female gonads, the ovaries, are located in the pelvis. They produce eggs and secrete the female hormones estrogen and progesterone. Estrogen is involved in the development of female sexual features.

Both estrogen and progesterone are also involved in pregnancy and the regulation of the menstrual cycle.

Table -1 Table of Endocrine glands, their hormones, and the action of the hormone

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence endocrine glands ,Their hormones and the action of hormone

Functions of hormones in adolescence Class 8

Problems with The Endocrine System

Too much (hyperfunction) or too little (hypofunction) of any hormone can be harmful to the body. For example, if the pituitary gland produces too much growth hormone, a child may grow excessively tall. If it produces too little, a child may be abnormally short.

Endocrine disorders are typically grouped into two categories:

An endocrine disease that results when a gland produces too much or too little of an endocrine hormone, is called a hormone imbalance.

Endocrine disease is due to the development of lesions (such as nodules or tumors) in the endocrine system, which may or may not affect hormone levels.

The following are just a few of the many disorders that can result from an improperly functioning endocrine system.

1. Gigantism (acromegaly) and other growth hormone problem: Acromegaly is a disorder in which the anterior pituitary produces too much growth hormone (GH).

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence gigantism.jpg

This causes an increased growth in bone and soft tissue, especially in the extremities—nose, jaw, fingers, and toes. If the disorder occurs in children who have not yet fully developed, the increased levels of GH also result in the exceptional growth of the long bones. This condition, a variation of acromegaly, is known as gigantism.

2. Pituitary dwarfism: Pituitary dwarfism or growth hormone deficiency is a condition in which the pituitary gland does not make enough growth hormone. This results in a child’s slow growth pattern and unusually small stature (below average height).

3. Hyperthyroidism: Hyperthyroidism is a condition in which the levels of thyroid hormones in the blood are excessively high.
Symptoms may include weight loss, nervousness, tremors, excessive sweating, increased heart rate and blood pressure, protruding eyes, and swelling in the neck from an enlarged thyroid gland (goiter).

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Hyperthyrodism.jpg

 

4. Hypothyroidism: Hypothyroidism is when the levels of thyroid hormones in the blood are abnormally low. Thyroid hormone deficiency slows body processes and may lead to fatigue, a slow heart rate, dry skin, weight gain, constipation, and, in kids, slowing growth and delayed puberty.

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence hypothyroidism.jpg

 

5. Diabetes mellitus: Disorder in which the body’s cells cannot absorb glucose, either because the pancreas does not produce enough insulin or the cells do not respond to the effects of insulin that are produced. It has two types.

Type-1 Diabetes:

When the pancreas fails to produce enough insulin, type 1 diabetes (previously known as juvenile diabetes) occurs. Type 1 diabetes can cause long-term complications, including kidney problems, nerve damage, blindness, early coronary heart disease, and stroke.

To control their blood sugar levels and reduce the risk of developing diabetes complications, kids need regular injections of insulin.

Type-2 Diabetes :

Unlike type 1 diabetes, in which the body can’t produce normal amounts of insulin, in type 2 diabetes the body is unable to respond to insulin normally.

Children and teens with this condition tend to be overweight, and it is believed that excess body fat plays a role in the insulin resistance that characterizes the disease.

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence diabetes

Hormonal changes during adolescence for Class 8

6. Adrenal insufficiency: This condition is characterized by decreased function of the adrenal cortex and the consequent underproduction of adrenal corticosteroid hormones.

The symptoms of adrenal insufficiency may include weakness, fatigue, abdominal pain, nausea, dehydration, and skin changes.

7. Addison’s disease: Disorder in which the adrenal cortex underproduces cortisol and aldosterone, resulting in the disruption of numerous bodily functions.

8. Cushing syndrome: If the condition is due to a tumor in the pituitary gland that produces excessive amounts of corticotropin and stimulates the adrenals to overproduce corticosteroids, it’s known as Cushing’s disease.

Symptoms may take years to develop and include obesity, growth failure, muscle weakness, easy bruising of the skin, acne, high blood pressure, and psychological changes. Moon face- a rounded shape of the face that develops from a specific pattern of fat distribution.

9. Precocious puberty: Body changes associated with puberty may occur at an abnormally young age in some kids if the pituitary hormones that stimulate the gonads to produce sex hormones rise prematurely.

10. Polycystic ovary syndrome: Overproduction of androgens interfere with the development of eggs and their release from the female ovaries. PCOS is a leading cause of infertility.

Adolescent Development

A critical and rapid transition

WHO identifies adolescence as the period in human growth and development that occurs after childhood and before adulthood, from ages 10 to 9.

It represents one of the critical transitions in the life span and is characterized by a tremendous pace of growth and change that is second only to that of infancy.

Biological challenges as young people transition from childhood to adulthood. It can seem like teens have processes that drive many aspects of this growth and development,

The onset of puberty marks the passage from childhood to adolescence. The biological determinants of adolescence are fairly universal;

however, the duration and defining characteristics of this period may vary across time, cultures, and socioeconomic situations.

Key developmental experiences

The process of adolescence is a period of preparation for adulthood during which time several key developmental experiences occur.

Besides physical and sexual maturation, these experiences include movement toward social and economic independence, and development of identity, the acquisition of skills needed to carry out adult relationships and roles, and the capacity for abstract reasoning.

While adolescence is a time of tremendous growth and potential, it is also a time of considerable risk during which social contexts exert powerful influences. one foot in childhood and one in adulthood as they navigate the changes in their bodies and minds.

 

WBBSE Solutions For Class 8 School Science Chapter 9 Endocrine System and Adolescence Key developmental experiences

Some of the normal changes going on for teens

  1. With the onset of puberty, preteens and teenagers experience rapid growth and changes in their bodies, develop sexually, and become increasingly aware of their body image.
  2. Teens develop their own morals, values, and self-direction; they test limits and try on different points of view; they develop a conscience.
  3. Social skills continue to develop and include romantic relationships.
  4. Teens have an increased awareness of self, which can include feeling self-conscious and fluctuating high or low self-esteem,
  5. Teens continue to develop cognitively, with an increased capacity for problem-solving, decision-making, and abstract thinking;
  6. however, their thinking is still more impulsive than adults; for example, the mere presence of peers can encourage them to engage in risky behavior.

Changes during Adolescence

Physical

  1. Physical changes (e.g., growth spurt and skeletal and structural changes) are rapid and visually apparent.
  2. Considerable diversity in physical developmental rates occurs due to genetics, environmental factors, and health issues.
  3. Distinct gender differences are evident in size, strength, and age of growth spurt (e.g., girls around age 12 and boys around age 14).
  4. Self-esteem changes due to adolescents’ home and school lives.
  5. Preoccupations with the self lead to critical self-examination and subsequently to the formation of self-perceptions.
  6. Argumentative and aggressive behaviors become evident and often disturb parents and teachers.

Psychosocial

  1. Friendships form and social interactions increase, which have the potential for boosting self-esteem and reducing anxiety.
  2. Distinct gender differences occur in socialization patterns (e.g., females tend to have smaller numbers of close friends and males tend to have larger “social networks”).
  3. Allegiance and affiliation shift from parents and teachers to friends and peers.
  4. Social tasks and situations are handled without adult supervision and advice.

Cognitive

  1. Higher levels of cognitive functioning (e.g., reasoning and higher-level thought processes) develop.
  2. Moral and ethical choices are now possible and often guide behavior.
  3. Development diversity leads to varying abilities to think and reason.
  4. Cognitive ability is often affected by overall socialization.
  5. Perspectives about past, present and future developments that allow enhanced perspectives of time.
  6. Language and overall verbalization skills increase, allowing improved communication in both school and home situations.

Significance of Adolescence Stage

Adolescence is a significant period because it is a period of:

1. Rapid physical development

It is a period of vital physical as well as physiological changes and developments. At this stage, all the external and internal body parts and organs achieve their full form and maturity.

2. Rapid mental development

During the early adolescence period, rapid mental development occurs. These give rise to the need for later mental adjustments and the necessity for establishing new attitudes, values, and interests.

The adolescent is mentally alert at this stage. He not only develops his intellectual power but also his capacity to critical thinking.

3. Rapid social development

It is a period of social development and adjustment. In this stage, the child enters a new field of social responsibility. The adolescents become socially conscious, self-assertive, and loyal towards their group; they develop cooperation and friendship and become responsible.

4. Stage of emotional development

Traditionally adolescence has been thought of as a period of heightened emotionality resulting from glandular and other changes. The heightening is characterized by a high degree of instability.

Importance of the endocrine system in growth Class 8

The adolescents also develop dependency and sometime independency. They also develop some special feelings like – pride, humility, curiosity, guilt, hero-worshipping, etc.

All these emotions must be properly guided and they should be provided knowledge to control their emotions at this stage.

5. Rapid sexual development

A number of internal and external changes take place in the sexual characteristics of boys and girls during the adolescence stage. In the later part of this stage, they achieve sexual maturity.

6. Rapid moral development

It is also a period of moral development and changes in morality. Their moral outlook becomes progressively more abstract. Moral convictions become more concerned with ‘what is right’ and justice emerges as a dominant moral force.

Their moral judgment becomes less egocentric at this stage. They develop an attitude towards service to mankind.

Problems of Adolescence Stage

The problems of adolescence may be summarized in the following manner:

1. Sex Problems

We have read that all the aspects of adolescent development are basically conditioned by physical changes. The onset of puberty gives the physical excitement never experienced before.

The adolescent reacting to these experiences is excited, often without realizing what is happening to him. Some react with pleasure or excitement and some others experience shame, disgust, confusion, anxiety, and guilt. They may lead to sexual maladjustment.

2. Emotional Problem

Heightened emotionality is a major problem of adolescence. Adolescents experience excessive emotion and they do not have sufficient control over violence.

Excitability and anger may find expression in their destructive form and may lead to law and order problems. The emotion of love, suspicion, jealousy, frustration, and revengefulness is very common among adolescents. Thus emotional immaturity is a major problem in adolescence.

3. Social Problem

Every society has its own customs and traditions, which it wants to maintain. Every individual has to follow these social values but often adolescents think all these are outdated and they are not willing to obey

This leads to conflicts. Physical development has many social implications. Sexual development necessarily includes heterosexual orientation and they want to take part in social activities with the opposite sex.

The denial of this desire often makes them discontented and restless. Drug addiction is a major social problem during adolescence.

Drugs are powerful chemicals that when taken into the body change the functions of the body, influence the mind, and therefore, sometimes even change the behavior of the person.

Adolescent boys and girls should avoid drugs to maintain physical, mental and social well-being which are necessary to live a purposeful, fruitful, and satisfying life in this world. Thus, a number of social problems disturb adolescents.

 

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production LAQs

WBBSE Chapter 8 Human Food And Food Production Long Answer Questions

Question 1. What are kharif and rabi crops? Write their differences.
Answer:

Crop Production and Management

We know that the energy from food is utilized by organisms for carrying out their various bodily functions, such as digestion, respiration, and excretion.

We get our food from plants, animals, or both. Since we all need food, how can we provide food to a large number of people in our country? To provide food for a large population— regular production, proper management, and distribution of food are necessary.

Till 10,000 B.C. people were nomadic. They were wandering in groups from place to place in search of food and shelter. They ate raw fruits and vegetables and started hunting for animals for food.

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production LAQs

Later, they could cultivate the land and produce rice, wheat, and other food crops. Thus, was born ‘Agriculture’. When plants of the same kind are grown and cultivated in one place on a large scale, they are collectively called a crop.

For example, a crop of wheat means that all the plants grown in a field are of wheat. We already know that crops are of different types like cereals, vegetables, and fruits.

These can be classified on the basis of the season in which they grow. India is a vast country. The climatic conditions like temperature, humidity, and rainfall vary from one region to another.

Accordingly, there is a rich variety of crops grown in different parts of the country. Despite this diversity, two broad cropping patterns can be identified. These are:

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Kharif Crops: The crops which are sown in the rainy season are called Kharif crops. The rainy season in India is generally from June to September. Paddy, maize, soybean, groundnut, cotton, etc., are Kharif crops.

Rabi Crops: The crops grown in the winter season are called rabi crops. Their time period is generally from October to March. Examples of rabi crops are wheat, gram, pea, mustard, and linseed.

Besides these, pulses and vegetables are grown during summer in many places. Basic Practices of Crop Production Cultivation of crops involves several activities undertaken by farmers over a period of time.

 

Kharif Rabi
Season of sowing Rainy season Winter season
Cultivation period June to September October to March
Examples of such crops Paddy, maize and soybeans, pulses, and vegetables are grown during summer Wheat, gram, pea, and mustard

 

You may find that these activities are similar to those carried out by a gardener or even by you when you grow ornamental plants in your house. These activities or tasks are referred to as agricultural practices. These activities are listed below-

  1. Preparation of soil
  2. Sowing
  3. Adding manure and fertilizers
  4. Irrigation
  5. Protection from weeds, pests, etc
  6. Harvesting
  7. Storage.

WBBSE Class 8 Human Food Production Long Answer Questions

Question 2. Write about the preparation of soil for crop production.
Answer:

Preparation of soil:

The preparation of the soil is the first step before growing a crop. This involves turning the soil and loosening it so that roots can penetrate deep into the soil and also allows the roots to breathe easily.

Loosening of soil helps in the growth of earthworms and microbes which further loosens the soil and also adds humus to it. Need for the soil to be loosened – Soil is rich in minerals, water, air & some living organisms.

The dead plants and animals when decomposed, release nutrients back into the soil making it nutrient-rich. Loosening of soil brings the nutrient, rich soil to the top for the plants to use for their growth.

The process of loosening and turning the soil is called Tilling or Ploughing. Tilling / Ploughing is done by using Ploughs made of wood & iron.

Big pieces of soil or crumbs left in the plowed field are broken with the help of a plank. Leveling of soil is done with the help of a leveler which is important for the purpose of Sowing and Irrigation.

Tilling also ensures proper mixing of manure with soil. A home is also sometimes used for removing weeds and for plowing.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Preparation of soil

 

Agricultural Implements: Before sowing the seeds, it is necessary to break the soil to the size of grains to get a better yield. This is done with the help of various tools. The main tools used for this purpose are the plow, hoe, and cultivator.

Plough: This is being used since ancient times for tilling the soil, adding fertilizers to the crop, removing the weeds, scraping of soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Plough

Chapter 8 Human Food and Food Production Detailed Answers

Removing the weeds, scraping off the soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

There is a handle at one end of the shaft. The other end is attached to a beam that is placed on the bulls’ necks. One pair of bulls and a man can easily operate the plow.

The indigenous wooden plow is increasingly being replaced by iron plows nowadays.

Hoe: It is a simple tool that is used for removing weeds and for loosening the soil. It has a long rod of wood or iron. A strong, broad, and bent plate of iron is fixed to one of its ends and works like a blade. It is pulled by animals.

Cultivator: Nowadays plowing is done by tractor-driven cultivators. The use of cultivators saves labor and time. For plowing small agricultural land or flower garden nowadays power tiller is used.

WBBSE Solutions For Class 8 School Science Long Answer Type Questions WBBSE Solutions For Class 8 School Science Short Answer Type Questions
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WBBSE Class 8 History Multiple Choice Questions WBBSE Solutions For Class 8 History
WBBSE Solutions For Class 8 Geography

 

Question 3. What are manures and fertilizers? Write their difference.
Answer:

Adding manure and fertilizers:

The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilizers.

Soil supplies mineral nutrients to the crop. These nutrients are essential for the growth of plants. Continuous growing of crops makes the soil poorer in certain nutrients.

Therefore, farmers have to add manure to the fields to replenish the soil with nutrients. This process is called manuring. Improper or insufficient manuring results in weak plants.

Manure is an organic substance obtained from the decomposition of plant or animal wastes. Farmers dump plant and animal waste in pits in open places and allow it to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.

Fertilizers are chemical substances that are rich in a particular nutrient. How are these different from manure? Fertilizers are produced in factories.

Some examples of fertilizers are- urea, ammonium sulfate, superphosphate, potash, and NPK (Nitrogen, Phosphorus, and Potassium). The use of fertilizers has helped farmers to get a better yield of crops such as wheat, paddy, and maize.

But excessive use of fertilizers has made the soil less fertile. Fertilizers have also become a source of water pollution. Therefore, in order to maintain the fertility of the soil,

we have to substitute fertilizers with organic manure or leave the field uncultivated (fallow) in between two crops.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Adding manure and fertilisers

 

The use of manure improves soil texture as well as its water-retaining capacity. It replenishes the soil with all the nutrients.

Another method of replenishing the soil with nutrients is through crop rotation. This can be done by growing different crops alternately.

Farmers sometimes grow legumes as fodder in one season and wheat in the next season. This helps in the replenishment of the soil with nitrogen.

In the previous chapter, you learned about Rhizobium bacteria. These are present in the nodules of the roots of leguminous plants. They fix atmospheric nitrogen.

Differences between Fertiliser and Manure

 

Fertiliser Manure
(1) A fertilizer is an inorganic salt. (1) Manure is a natural substance obtained by the decomposition of cattle dung, human waste, and plant residues.
(2) A fertilizer is prepared in factories. (2) Manure can be prepared in the fields.
(3) A fertilizer does not provide any humus to the soil. (3) Manure provides a lot of humus to the soil.
(4) Fertilisers are very rich in plant nutrients like nitrogen, phosphorus, and potassium. (4) Manure is relatively less rich in plant nutrients.

 

WBBSE Class 8 Science Long Answer Solutions

Advantages of Manure: Organic manure is considered better than fertilizers. This is because It enhances the water-holding capacity of the soil. It makes the soil porous which exchange of gases becomes easy.

Question 4. What is irrigation? Describe the modern methods of irrigation of crop fields.
Answer:

Irrigation:

All living beings need water to live. Water is important for the proper growth and development of flowers, fruits, and seeds of plants. Water is absorbed by the plant roots.

Along with water, minerals, and fertilizers are also absorbed. Plants contain nearly 90% water. Water is essential because the germination of seeds does not take place under dry conditions.

Nutrients dissolved in the water get transported to each part of the plant. Water also protects the crop from both frost and hot air currents. To maintain the moisture of the soil for healthy crop growth, fields have to be watered regularly.

The supply of water to crops at different intervals is called irrigation. The time and frequency of irrigation vary from crop to crop, soil to soil, and season to season.

In summer, the frequency of watering is higher due to the increased rate of evaporation of water from the soil and the leaves.

Sources of irrigation: The sources of irrigation are— wells, tube wells, ponds, lakes, rivers, dams, and canals.

Traditional Methods of Irrigation

The water available in wells, lakes, and canals is lifted up by different methods in different regions, for taking it to the fields.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Taditional methods o0f irrigation

Protection from Weeds

In a field, many other undesirable plants may be Cattle or human labor is used in these methods. So these methods are cheaper but less efficient. The various traditional ways are:

  1. Moat (pulley system)
  2. Chain pump
  3. Dhekli, and
  4. Rahat (Lever system)

Pumps are commonly used for lifting water. Diesel, biogas, electricity, and solar energy are used to run these pumps.
Modern Methods of Irrigation Modern methods of irrigation help us to use water economically. The main methods used are as follows:

Sprinkler System: This system is more useful on uneven land where sufficient water is not available. The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals.

When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. The sprinkler is very useful for sandy soil.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production drip system

WBBSE Class 8 Science Important Long Answer Questions

Drip system: In this system, the water falls drop by drop just at the position of the roots. So it is called a drip system. It is the best technique for watering fruit plants, gardens, and trees.

The system provides water to plants drop by drop. Water is not wasted at all. It is a boon in regions where the availability of water is poor and grows naturally along with the crop. These undesirable plants are called weeds.

The removal of weeds is called weeding. Weeding is necessary since weeds compete with crop plants for water, nutrients, space, and light.

Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings.

Question 5. Write about the process of propagation, planting, and storage of mango.
Answer: 

Mango:

Mango (Mangifera indica) belonging to Family Anacardiaceae is the most important commercially grown fruit crop in the country. Mango is the leading fruit crop of India and is considered to be the king of fruits.

Besides the delicious taste, excellent flavor, and attractive fragrance, it is rich in vitamins A and C. The tree is hardy in nature and requires comparatively low maintenance costs.

Mango occupies 22% of the total under fruits comprising 1.2 million hectares, with a total production of 11 million tones. b

Uttar Pradesh and Andhra Pradesh are having the largest area under mango each with around 25% of the total area followed by Bihar, Karnataka, Kerala, and Tamil Nadu.

Mango fruit is utilized at all stages of its development both in its immature and mature state. Raw fruits are used for making chutney, pickles, and juices.

The ripe fruits besides being used for dessert are also utilized for preparing several products like squashes, syrups, nectars, jams, and jellies.

India is the largest mango-producing country, accounting for about 60% of world production, the export of fresh fruit is Limited to Alphonso and Dashehari varieties.

India’s share in the world mango market is about 15 percent. Mango accounts for 40 percent of the total fruit exports from the country. There is good scope for increasing the area and productivity of mango in the country.

 

 

Climate: Mango can be grown under both tropical and sub-tropical climates from sea level to 1400 m altitude, provided there is no high humidity, rain, or frost during the flowering period.

Places with good rainfall and dry summer are ideal for mango cultivation. It is better to avoid areas with winds and cyclones which may cause flower and fruit shedding and breaking of branches.

Soil: Mango comes up on a wide range of soils from alluvial to laterite provided they are deep (minimum 6′) and well drained. It prefers slightly acidic soils.

Varieties: Though there are nearly 1000 varieties of mango in India, only the following varieties are grown in different states: Alphonso,

the simplest way is by pouring the paddy down from a height on a windy day to a large square mat on open Bangalore, Banganpalli, Bombai, Bombay Green, Dashehari, Fazli, Fernandin, Himsagar, Kesar, KishenBhog, Langra, Mankhurd, Mulgoa, Neelam, Samarbehist, Chausa, Suvarnarekha, Vanaraj, and Zardalu.

Recently some mango hybrids have been released for cultivation by different institutes/ universities. These are – mallika, amrapali, mangeera, ratna, arkaanmol, etc.

Propagation:

Farmers should always get vegetatively propagated, true-to-type plants from recognized nurseries. Inarching, veneer grafting, side grafting, and epicotyl grafting are the popular methods of propagation in mango.

Planting:

Land should be prepared by deep plowing followed by harrowing and leveling with a gentle slope for good drainage.
Planting is usually done in the month of July- August in rainfed areas and during February- March in irrigated areas. In case of heavy rainfall zones, planting is taken up at the end of the rainy season.

One-year-old healthy, straight-growing grafts from reliable sources can be planted at the center of pits along with the ball of the earth intact during the rainy season in such a way that the roots are not expanded and the graft union is above the ground level. Plants should be irrigated immediately after planting.

Fertiliser Application: Fertilizers may be applied in two split doses, one half immediately after the harvesting of fruits in June/July and the other half in October, in both young and old orchards followed by irrigation if there are no rains. Foliar application of 3% urea in sandy soils is recommended before flowering.

Question 6. Write the geographical conditions necessary for tea plantations.
Answer:

Tea:

Tea is the dried leaf of a bush. It contains theine and when added to boiling water along with sugar and milk, it gives a very cheap and stimulating drink.

Thus it is the most important beverage crop in India. Tea bush is supposed to be indigenous to China but it was reported by Major Robert Bruce in 1823 that indigenous tea bushes grew wild on the hill slopes of upper Assam. In the year 1840, tea seeds were.

Irrigation: Young plants are watered frequently for proper establishment. In the case of grown-up trees, irrigation at 10 to 15 days intervals from fruit set to maturity is beneficial for improving yield.

Harvesting and yield: The yield of mango varies greatly, depending upon the variety and agro-climatic conditions prevailing in a region. Grafted mango trees start bearing from the fifth year onward. However, seedling trees may take 8-10 years.

Economic Importance: Raw fruits of local varieties of mango trees are used for preparing various traditional products like raw slices in brine, amchur, pickle, murabba, chutney, pane (sharbat), etc.

Presently, the raw fruit of local varieties of mango is used for preparing pickles and raw slices in brine on the commercial scale while fruits of the Alphonso variety are used for squash in the coastal western zone.

The wood is used as timber, and dried twigs are used for religious purposes. The mango kernel also contains about 8-10% good-quality fat which can be used for saponification. Its starch is used in the confectionery industry.

Weed control and Plant protection: The mango orchard should be completely free from weeds. In order to control weeds, shallow hoeing at quarterly intervals should be done. Black plastic mulch should be used to restrict the germination of weed seeds and suppression of weed growth.

Mango crop suffers seriously from pests: hopper, mealy bug, fruit fly, shoot and stem borer, and stone weevil. The Hoppers are most divesting during the flowering period as they suck the sap from tender shoots, leaves, and panicles.

Proper pesticides are recommended for the protection of trees imported from China and commercial tea plantations were set up in the Brahmaputra valley.

There are four main types of tea: green tea, black tea, oolong tea, and white tea. There are even more varieties, including flavored, scented, and “herbal infusions,” but for the sake of simplicity, we’ll focus on the big four right now.

What many people don’t know is that these four types of tea come from one plant, not four different species of plant.

All tea begins with the plant known as Camellia sinensis, it’s the way the tea leaves are processed that gives us the different teas and their specific taste, color, and scent.

Conditions of Growth

Tea bush is a tropical and sub-tropical plant and thrives well in a hot and humid climate. There is a very close relationship between climate, yield, and quality of tea. The ideal temperature for its growth is 208-30°C and temperatures above 35°C and below 10°C are harmful to the bush.

It requires 150-300 cm of annual rainfall which should be well distributed throughout the year. While the prolonged dry spell is harmful to tea, high humidity, and heavy demand morning fog favor the rapid development of young leaves.

Alternate waves of warm and cool winds are very helpful for tea leaves. Tea is a shade-loving plant and develops more vigorously when planted along with shady trees.

In order to increase the yield, the proper dose of nitrogenous fertilizers such; as ammonium sulfate should be given to the soil.
Although tea requires heavy rainfall for its growth, stagnant water is injurious to its roots.

It is, therefore, grown on hill slopes where water drains away easily and water-logging does not take place. However, it grows equally well in the valley if the drainage is good. Most of the tea plantations in India are found at elevations varying from 600 to 1,800 meters above sea level.

Tea is a labor-intensive crop and requires an abundant supply of cheap and skilled labor, especially at the time of plucking the tea leaves.

This is a tedious process that requires skilled manipulation of fingers for plucking two leaves and a bud at a time. For this purpose, women laborers are employed in large numbers.

Distribution

Tea cultivation in India is highly concentrated in a few selected pockets. The following three areas of tea cultivation are identified according to their importance as tea producers and their location.

North-Eastern India: It is more or less a triangular area mainly in Assam and West Bengal. Assam is the largest producer of tea accounting for over 51 percent of the production and over 53 percent of the area under tea cultivation in India.

West Bengal is the second largest producer contributing over 22 percent of India’s tea from about one-fourth of the country’s total area under tea cultivation.

The entire tea of West Bengal is produced in three northern districts of Darjeeling, Jalpaiguri, and Coochbehar.
South India: In South India tea is produced in Nilgiri, Cardamom, Palni, and Anaimalai hills in Tamil Nadu, Kerala, and Karnataka states.

Northwest India: Some of the tea is produced in the Dehra Dun, Almora, and Garhwal districts of Uttaranchal and in Kangra Valley and Mandi district of Himachal Pradesh. Green tea is produced in the Kangra valley of Himachal Pradesh.

Plantations

Planting: Planting is a crucial operation as it basically determines the development and productive level of tea throughout its economic life.

Wrong planting of good planting materials is doubly unproductive as an investment is lost both on account of producing the plants and in the failure to put them up for productivity. Therefore, care, planning, and refinement of techniques are essential for long-term benefits.

Pruning: It basically helps in maintaining the plant as a low bush in a phase of continuous vegetative growth. Pruning both stimulates and controls growth.

It removes dead, diseased, and overage wood, and thus helps rejuvenate bushes that have crossed the period of maximum productivity.

Fertilizer: The nutrients that are removed from the plant as yield and from the soil by the plant for its growth, should be replenished.

ideally, nutrient requirements should be related to local soil conditions in addition to yield and they must be monitored continuously to ensure an optimum balance of nutrients.

Weed control: Weeds affect tea by competing with it for moisture, nutrients, and sunlight. The ultimate effect is a considerable reduction in yield.

Thus, the timing of weed emergence relative to the growth stages of tea is an important parameter in weed management. Apart from directly causing crop losses, weeds in tea areas also act as secondary hosts for some important pests of tea.

Pest Management: The simultaneous presence of different species of mites and insects, each with their characteristic mode of feeding, diverse habitat, and seasonal cycles, call for optimal management of the pests which should be both ecologically and economically sound.

Crop duration and harvest: Plucking commences when the tea bush is 3 years old. The plucking of the extreme tip of the growing branch consists of an unopened bud together with two leaves popularly known as “Two leaves and a bud”, while fine plucking is anything less than this.

In South India, plucking continues throughout the year at weekly intervals during March-May and at intervals of 10 -14 days during the other months.

Processing of tea

Once workers gather enough quantities of tea leaves, their stash is quickly carried over to a tea factory located right on the plantation.

The factory is placed close to the source of the leaves because once the tea is plucked, oxidation immediately begins. The oxidation process is important in understanding tea — it must be closely monitored during production and is essential in determining the type and quality of the tea.

Oxidation is what happens when you cut up a piece of fruit and leave it out for too long — the color of the fruit changes, usually turning brown or black. Depending on the type of tea you want, oxidation can be a necessary part of processing tea leaves.

Tea tasting is the process in which a trained taster determines the quality of a particular tea. Due to climatic conditions, topography, manufacturing process, and different clones of the Camellia sinensis plant (tea), the final product may have vastly different flavors and appearances.

These differences can be tasted by a trained taster in order to ascertain the quality prior to the sale of possibly blended tea.

Long Answer Format for Class 8 Human Food

Question 7. What are the advantages of poultry farming? Describe in brief, the deep litter system of poultry farming.
Answer:

Poultry farming:

Poultry farming is the raising of domesticated birds such as chickens, ducks, turkeys, and geese, for the purpose of farming meat or eggs for food. Poultry is farmed in great numbers with chickens being the most numerous.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production polutry farming

 

Advantages of Chicken farming

  1. The initial investment is a little lower than layer farming.
  2. The rearing period is 6-7 weeks only.
  3. More flocks can be taken in the same shed.
  4. Broilers have high feed conversion efficiency i.e. least amount of feed is required for unit body weight gain in comparison to other livestock.
  5. Faster return from the investment.
  6. Demand for poultry meat is more compared to sheep/goat meat.
  7. Important terminologies associated with poultry

Breed: Birds with a common origin, having specific characteristics, such as body shape, that distinguish them from other groups within the same species.

Strain: Chicks having specific characteristics, produced in specific farms by breeding.

Variety: The subdivisions of breeds based on specific characteristics, for example- white Leghorn, brown Leghorn, etc.

Chick: Young chicken of either sex from day 1 to about 5-6 weeks of age.

Grower: Chicken of either sex from 6 weeks to 6 months of age.

Cock: A mature male chicken.

Cockerel: A male chicken from day 1 to about 1 year of age.

Hen: A mature female chicken.

Pullet: A female chicken less than one year of age.

Fowl: Generally refers to larger birds.

Broiler/ Fryer: A young bird of either sex, usually of meat-type breeds up to 8-10 weeks of age and weighing 1.5-2.5 kg. The term broiler is applied to chicks that have especially been bred for rapid growth.

  1. Broiler strains are based on hybrid crosses between Cornish White, New Hampshire, and White Plymouth Rock.
  2. In broiler production there are two main production phases:
  3. keeping of parent stock and production of day-old-chicken and
  4. Growing and finishing of broilers.

Layers: Layers are efficient egg producers, breeds used for egg production in the industrial production system are almost entirely based on the White Leghorn and Rhode Island Red.

  1. Selection and crossbreeding techniques have resulted in productive laying hens producing 15 – 19 kg of eggs per year. In layer production,
  2. sometimes two phases of production are recognized:
  3. growing phase up to approximately 140 days; and
  4. productive phase from 140 – 560 days.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production eggs

 

Culling: The process of eliminating undesirable or non-reproductive animals.

Litter: The accumulation of materials, such as hay, sawdust, etc., to form the bed or floor of an animal farm.

Rooster: A young chick of meat type, weighing more than 1.5 kg.

Mash: A form of completely balanced feed that is finely ground and mixed so that birds can easily consume them and got proper nourishment.

Different Breeds Of Chicken

Different breeds are classified in different ways-

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Example- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According To Utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

3. According To Weight

Light breed: These breeds have body weights of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have body weights of more than 3 kg. Example- Aseel, Brahma, etc

According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Examples- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According to the utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

According to weight

Light breed: These breeds have a body weight of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have a body weight of more than 3 kg. Example- Aseel, Brahma, etc

4. According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

Non-sitter: The mothers do not sit on their eggs. Eggs are generally incubated in artificial incubator machines. Examples- Leghorn, Minorca, etc.

Different systems of fowl or chicken farming Generally different systems of farming are followed by poultry keepers. These may be-

  1. Free range or extensive system
  2. Semi-intensive system
  3. Intensive system:
  4. Battery cage system,
  5. Deep litter system.

1. Free range system

Free-range poultry farming consists of poultry permitted to roam freely instead of being contained in any manner. A free-range chicken must have daytime access to open-air runs for at least half of their life.

Free-range chickens grow slowly. Free-range poultry production requires that the poultry have access to the outside. The birds are to be protected from predatory animals and intruders. At present, due to several disadvantages and a shortage of space, this method is almost obsolete.

2. Semi-intensive system

This system is adopted where the amount of free space available is limited. It is necessary to allow 20-30 square yards per bird of outside run.

The birds are kept in a large enclosed area during the day time and are kept in adjacent farmhouses during the night and in unfavorable weather conditions.

3. Intensive system

This system is usually adopted where land is limited. In this system, the birds are confined to the house entirely with no access to the land outside.

The intensive system may be of the following types-

Battery cage system: Battery cages are a housing system used for various animal production methods, but primarily for egglaying hens.

The name arises from the arrangement of rows and columns of identical cages connected together, sharing common divider walls, as in the cells of a battery.

In a battery cage, the rate of food and water, and the duration and intensity of light are tightly controlled. There is no access to the natural environment, nor any opportunity to conduct natural behaviors such as perching, dust bathing, wing flapping or nesting.

Environmental conditions are automatically controlled, including light duration, which mimics summer day length. This stimulates the birds to continue to lay eggs all year round.

Advantages

  1. A greater number of birds is reared per unit of area
  2. Facilitates correct maintenance of record
  3. Helps in identifying poor producers and prompt culling
  4. It helps in the production of clean eggs
  5. Easy control of parasitic disease
  6. Prompt steps to control feed wastage.

The cage method of housing is ideal for the area with moderate climate conditions where the day temperature in summer does not high and the temperature does not fall too low.

Egg production of the caged layer was reported to be more than those kept in a deep litter system.

Deep litter system: Deep litter system is commonly used all over the world. Litter is the substance that is used for farm animals to sleep on.

In the deep litter system, the poultry birds are kept in large pens of up to 250 birds each, on the floor covered with litter like straw, sawdust, or dried leaves up to a depth of 6-8 inches.

Deep litter is a method of chicken waste management that calls for droppings and bedding material to compost inside the chicken coop instead of being cleaned out and replaced regularly.

With the deep litter method, a carbon-based litter absorbs nitrogen from chicken droppings, which ferments in an odor-free process to produce rich, valuable humus just as in a traditional compost pile.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production different system of fowl or chicken farming..

Advantages

  1. It is economical, hygienic, comfortable, and safe for birds
  2. Controls diseases and vices
  3. It increases the efficiency of production
  4. Materials such as paddy husks, sawdust, dried leaves, chopped straw, and groundnut kernels depending upon the availability can be used as litter materials.
  5. Nutritional value of chicken
  6. Naturally low in sodium.
  7. 100 grams of skinless boneless chicken has 31 grams of protein, or more than half the recommended daily allowance.

A good source of niacin, which aids in metabolism; vitamin B6, important to the immune system and blood sugar; biotin, which aids in cell growth; vitamin Bu, involved in nerve and red blood cell maintenance.

  1. Nutritional value of egg
  2. Contain one of the highest quality proteins of any food.
  3. A large egg contains about 70 calories and 6 grams of protein.
  4. A single egg contains 13 essential nutrients.
  5. Egg proteins contain time-release energy which helps maintain blood glucose levels and makes people feel full and energized longer.

WBBSE Chapter 8 Food Production Study Guide

Question 8. Mention the benefits of plowing. What is sowing? What are the factors that affect the irrigation requirements of crops?
Answer:

Benefits of plowing:

Ploughing is beneficial because of the following reasons:

  1. The loose soil allows the plant roots to penetrate freely deeper into the soil and to breathe easily since loose soil can hold a lot of dirt in its spaces.
  2. The loose soil helps in the growth of worms and microbes which in turn adds humus to the soil.
  3. Plowing uproots the weeds and brings the nutrient-rich soil to the top so that the plants can use the nutrients easily.
  4. The process of scattering seeds in the ground soil for growing the crop plants is called sowing.

Factors affecting Irrigation requirements are-

  1. Nature of crop
  2. Nature of soil
  3. Season

Question 9. The figure shows yields of two crop fields (Plot A and Plot B) that have been treated with manure and chemical fertilizers :
Answer:

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production plot a and b

 

Question 10. What is the reason for the different patterns of the two graphs? What is a wedding? Name two harvest festivals.
Answer:

Reason for the different patterns of the two graphs:

Plot B shows a sudden increase in yield due to the quick absorption of chemical fertilizers. Further gradual decline happens due to the nonreplenishment of organic matter in the soil, due to the death of microbes, etc.

Thus chemical fertilizers may be beneficial for a short time but it quickly turns fertile soil into infertile one. Manures maintain the sustainability of soil fertility.

It is beneficial for the long run and maintains durable crop yielding as is reflected in plot A.

Wedding:

The process of removing unwanted plants or weeds from a crop field is called weeding.

Harvest Festivals :Baisakhi and Pongal are two harvest festivals.

Human Food and Food Production WBBSE Comprehensive Answers

Question 10. How is honey prepared? Why is the honey bee called a social insect?
Answer:

Preparation Of Honey:

Worker bees gather nectar from flowers and carry nectar within their honey sac, where it undergoes mixing with a specialized enzyme.

After returning to the hive, the worker bee vomits the nectar in the honey chamber and moves its wings very rapidly. Then the liquid from the nectar gets evaporated by the flowing air and the stuff becomes honey.

A highly organized division of labor is found in the colony of honey bees. A good and well-developed colony of bees has 40 to 50 thousand individuals consisting of 3 casts: queen, drone, and worker.

The queen, after fertilization, lays both fertilized and unfertilized eggs. From unfertilized eggs, males emerge which are called drones whereas from % the fertilized eggs worker bees are produced.

The workers when fed on royal jelly, develop into queens. The total indoor and outdoor duties of the colony are performed by the workers only. The sole duty of the drone is to fertilize the virgin queen. This is why honey bees are known as social insects.

Question 11. Mention the nutritional values of fish. How is induced breeding of carp carried out?
Answer:

Fish Culture or Pisciculture

Fish is one of the most delicious and widely eaten aquatic animals and it is enriched with omega-3- fatty acid, a necessary constituent of a balanced diet.

As fish is a beloved food item all over the world, so its cultivation and harvesting are done on a larger scale in different parts of the globe.

Some branches of cultivation and harvesting fish are known as Fisheries, Pisciculture, Aquaculture, and Mariculture. Let us see the difference between these different ways of producing fish a larger scale.

Terminology

Fisheries- It deals with all the aspects of harvesting or raising economically important

Weight Loss: Though honey has more calories than sugar, when honey is consumed with warm water, it helps in digesting the fat stored in your body. Similarly, honey and lemon juice as well as honey and cinnamon help in reducing weight.

Energy Source: Honey contains about 64 calories per tablespoon. Therefore, honey is used by many people as a source of energy. On the other hand, aquatic (freshwater and marine) organisms like fish, prawns, crabs, pearls, etc.

Pisciculture- This is the method of fish farming in which fishes are raised in artificial way for breeding and transportation.

Aquaculture- Aquaculture though simply means fish farming, in a broader sense, it is farming of aquatic organisms like fish, prawns, etc., and plants for breeding and rearing.

Mariculture- Mariculture involves the cultivation of only marine organisms, unlike any aquatic organism. This is the method of fish farming which is done usually on a very broader scale means by forming an enclosed section of the ocean.

Type of fisheries

Depending on the type of resources, it may be of the following types-
Capture fisheries: The process of obtaining fish from natural resources like lakes, rivers, ponds, etc. is called capture fishing. Capture fisheries are the exploitation of aquatic organisms without stocking the seed.

Recruitment of the species occurs naturally. This is carried out in the sea, rivers, reservoirs, etc. Fish yield decreases gradually in capture fisheries due to indiscriminate catching of fish including brooders and juveniles.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing type of fisheers

 

Culture fisheries: It is the production of fish in a given body of water such as ponds, lakes, or reservoirs using scientific methods of feeding, breeding, etc.

so as to enhance the output is called culture fishing-A culture fishery is the cultivation of selected fishes in confined areas with utmost care to get maximum yield.

The seed is stocked, nursed, and reared in confined waters, and then the crop is harvested. Culture takes place in ponds, which are fertilized, and supplementary feeds are provided to fish to get maximum yield.

In order to overcome the problems found in capture fisheries to increase production, considerable attention is being given to the culture fisheries.

Fishing in India: Fishing in India is a major industry in its coastal states, employing over 14 million people. Fish production in India has increased more than tenfold since its independence in 1947.

According to the Food and Agriculture Organization (FAO) of the United Nations, fish output in India doubled between 1990 and 2010.

India is endowed with vast and varied aquatic resources (Marine and Inland) amenable for capture fisheries. India is the third-largest producer of fish and the second-largest producer of inland fish in the world.

The fisheries sector provides employment to over 11 million people engaged fully, partially, or in subsidiary activities pertaining to the sector, with an equally impressive segment of the population engaged in ancillary activities.

The potential of fish production from marine and inland sources has been estimated at 3.9 million tonnes and 4.5 million tonnes, respectively.

Inland Fisheries: Inland waters are aquatic-influenced environments located within land boundaries. This includes those located in coastal areas, even where adjacent to marine environments.

Inland water systems can be fresh, saline, or a mix of the two (brackish water). Inland resources comprise of rivers and canals, estuaries, floodplains, wetlands, lagoons, and reservoirs.

While the marine water bodies are used mainly for capturing fisheries resources, the inland water bodies are widely used both for culture and capture fisheries.

Inland capture fisheries of India have an important place; it contributes to about 30% of the total fish production.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing marine fisheers

 

Marine Fisheries: The captured marine fishery resource of India comprises a long coastline (8118 km.) and an Exclusive Economic Zone (EEZ) (2.025 sq. km).

Marine capture fisheries play a vital role in India’s economy, providing employment and income to nearly two million people. Out of the total fish production in India, about 70% is obtained from the sea.

This gives the idea that how important is the marine fishery with its great economic and commercial values.

There are two main coastlines in India i.e., the East coast and the West coast. Out of these two the west coast is more productive because of better circulation and more oceanic character of its water.

Several exploratory surveys of fish wealth in the deep water on both coasts have been done which indicates that like coastal fisheries, deep sea fisheries can also be of much commercial and economic value.

Carp Culture

Carp are various species of oily freshwater fish of the family Cyprinidae, a very large group of fish native to Europe and Asia. Carp is a large freshwater fish native to central Asia.

Introductions in many countries have helped to make carp the most widely distributed freshwater fish in the world. They are highly cultured and domesticated in aquaculture for food and ornamental purpose.

Freshwater fishes cultured in India are mainly major carp, minor carp, exotic carp, and other fishes. Fishes like Katla, mrigal, and rohu (rui) are 3 major carps of India. A lot of research, hybridization, reduce breeding have been carried out with carps distressfully.

Indian major carp grow fast and can reproduce even in artificial ponds. v. Minor carps are smaller in size than major carp. They do not produce as many eggs as major carp.

Kalbasu, bata,punti, etc., are minor carps. minor carp fishes grow to a size of 30- 100 2cm. with an average weight of 1 to 1.5 kg. The rate of egg production is very low in these fishes.

When the indigenous fishes are not favored for culture due to economic viability, exotic breeds are selected and cultured. These fishes yield nutritious food and earn foreign exchange.

Examples of exotic carp are silver carp, grass carp, and common carp. Other common freshwater fishes are – lata, maguro, single, koi, Tangra, Boal, tilapia, panda, bhetki, etc. However, these fishes are not carp.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production crap fish

WBBSE Class 8 Science Chapter 8 Descriptive Questions

Indian Carp culture: Indian aquaculture has been,n growing at a fast pace over the last two d^cpdes, with freshwater aquaculture contributing over 95% of the production.

The three major carps cultured in India, namely, Katla (Catla catla), rohu (Labeo rohita), and mrigal (Cirrhinus mrigala), contribute as much as 87 percent of the total Indian aquaculture production.

Three exotic carp were also introduced, namely, silver carp (Hypophthalmichthys molitrix); grass carp (Ctenopharyngodon idyllic), and common carp (Cyprinus carpio).

There are also several other medium and minor carp species, namely kalbos(Labeo calabash) bata (L. bata), and Puntif Puntius sarana), which are important in aquaculture.

Among catfishes, major (Ciarias batrachus) is the only species that is widely cultured, while the catfish, Singh (Heteropneustes fossilis) is cultured to some extent in the eastern states.

The finfish species of importance include climbing perch koi (Anabas testudineus), lata (Channa striata), and tilapia (Oreochromis mossambicus).

Preparation of pond

Pond preparation involves making the ponds weed and predator-free and generating adequate natural food for the survival and growth of fish.

Spawning: Because of constant temperature and favorable weather conditions, carps spawn all year round in India. Spawning takes place early in the morning when the water surface cools down to about 18 degrees.

The female carp swims near the water’s surface followed by the male carp in nuptial swimming and rubbing each other’s bodies. The female lays an egg and the male releases its milt and the eggs are fertilized.

Three days after fertilization, the eggs begin to hatch. The newly hatched larva (seedling) is about 5.5 mm long, delicate, and transparent, with a yolk sac attached to the belly.

It rarely swims but settles on the bottom or on some floating object. On the second day, the larva starts swimming, and on the third-day swims actively from surface to bottom.

During these stages, the larva or fry gets its nourishment from the yolk sac, which disappears on the third day and the fry now must search for food and eat.

Supplementary fry- feed in the form of hard-boiled egg yolk or powdered milk can be applied on the water surface at this time. When the fry grows slightly larger, about the size of a finger, it is called a fingerling.

Nursery ponds are constructed to rear carp fry or larvae. A normal-sized nursery pond measures 5 x 10 m, with a depth of 0.5 m. Before filling up the water the pond should be cleaned thoroughly to get rid of predators and parasites that may be destructive to the larvae. About 1,500 to 3,000 fries can be stocked in the nursery pond.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing prepation of pond

 

Rearing ponds where adult carp are cultured until they reach marketable size, are needed, which have dimensions of 15 x 50 m and depth of 1.5 to 2 m.

Rearing ponds should also be thoroughly cleaned before filling them with water. This is done by exposing the bottom and letting it dry thoroughly.

The next step involves the application of fertilizers, which encourages the growth of aquatic plants, moss, and algae, which are important natural food and also lead to the growth of microfauna.

Manure in the form of chicken dropping is the most commonly used being cheaper and more readily available in large quantities. When carp fry reaches a length of about 5 to 7 cm, they are transferred from the nursery pond to the rearing pond and allowed to grow to the adult stage.

Stocking ponds: Ponds are stocked with fish fries of the appropriate size. Fingerlings over 10 cm in size are recommended for stocking in culture ponds.

In composite fish farming, a combination of six species is cultured, namely, Katla, rohu, mrigal, and exotic carp like silver carp, grass carp, and common carp.

Supplementary feeds like groundnut oil cake and rice bran are fed to fishes during culture. At the end of the culture period of say 12 months, the fish will reach the marketable size and fetch attractive prices.

Aeration may be done mechanically to increase the concentration of dissolved oxygen in ponds, by paddle wheel aerators, aspirator aerators, and submersible pond aerators. It is also necessary to replace a certain amount of water at regular intervals.

Harvesting

Harvesting of fish is usually done after a culture period of 10 months to one year. However, fish attaining the marketable size can be harvested periodically depending on several factors,

which also reduces the pressure of density in the ponds and thereby provides sufficient space for the growth of fish.

Induced breeding of carps: Induced fish farming has allowed farmers to breed and raise species that do not naturally reproduce in captivity,

manipulate the timing of reproduction to suit production cycles, get fish to spawn on a predetermined date, and fertilize and incubate eggs under hatchery conditions.

The strategy is to inject the fish with one or more naturally occurring reproductive hormones or synthetic analogs to manipulate the maturation of gonads and ovulation.

Sewage-fed fishery: Increasing population, industrialization, and urbanization have created problems in the form of waste disposal.

Wastes arise from virtually all forms of human activities. The common means of disposal of these materials is to dump them outside the village or city limits, to burn them, or to discharge them into ponds and rivers.

But in recent times things have changed. The use of waste for productive purposes has generated a new idea of waste management. Sewage is a rich nutrient resource, cheaply available around big towns and cities.

It can be well-utilized: for fertilizing paddies, fishponds, and horticulture crops. Waste recycling also helps in maintaining a clean environment.

For fish cult urn sewage water from stabilizing tank well as the water after dilution can be utilized. Air-breathing fishes are more suitable to be cultured In sewage treatment ponds as they can survive In water with lesser dissolved oxygen content.

Fish like maguro, single, lata, tilapia, grass carp, etc., are the species of choice to be considered for culture in sewage-treated ponds.

Numerous species of fish are farmed in the sewage-fed ponds called burls In the East Kolkata wetlands.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production induced breeding of craps

 

Nutritional value of fish

Fish Is a food of excellent nutritional value, providing high-quality protein and a wide variety of vitamins and minerals, including vitamins A and D, phosphorus, magnesium, selenium, and Iodine in marine fish.

Its protein – like that of meat – is easily digestible and favorably complements dietary protein provided by cereals and legumes that are typically consumed in many developing countries.

Fishes may be classed as either whitefish or oily fish. Whlteflsh, such as rohu, Katla, mrigal, etc, contain very little fat (usually less than 1%) whereas oily fish, such as English, panda, etc, contain between 10-25%.

The latter, as a result of Its high-fat content, contains a range of fat-soluble vitamins (A, D, E, and K) and essential fatty acids, all of which are vital for the healthy functioning of the body.

Experts agree that, even in small quantities, fish can have a significant positive impact on improving the quality of dietary protein by complementing the essential amino acids that are often present in low quantities in vegetable-based diets.

But recent research shows that fish is much more than just an alternative source of animal protein. Fish oils in fatty fish are the richest source of a type of fat that is vital to normal brain development in unborn babies and infants. Without adequate amounts of these fatty acids, normal brain development does not take place.

Question 12. Mention the types of fisheries. Name two exotic carp.
Answer:

Types of fisheries:

On the basis of location, fisheries are classified as:

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production location fishers

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production SAQs

WBBSE Chapter 8 Human Food And Food Production Short Answer Type Questions

Question 1. What is food?
Answer:

Food:

Food is any nutritious substance that people or animals eat or drink or that plants absorb to maintain life and growth.

Food materials consist essentially of protein, carbohydrates, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy.

Question 2. What are cereal crops?
Answer:

Cereal Crops:

Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Maize, wheat, rice, etc are cereal crops.

Question 3. What is agriculture?
Answer:

Agriculture:

Agriculture is the process of producing food, feeding products, fiber, and other desired products by the cultivation of certain plants and the raising of domesticated animals (livestock).

WBBSE Class 8 Human Food Short Answer Solutions

Question 4. What is food processing?
Answer:

Food Processing:

Food processing is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms.

Food processing combines raw food ingredients to produce marketable food products that can be easily prepared and served by the consumer.

Food processing typically involves activities such as mincing and macerating, liquefaction, emulsification, cooking (such as boiling, broiling, frying, or grilling), pickling and preservation, canning or jarring (primary processing such as dicing or slicing, freezing or drying when leading to secondary products are also included).

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production SAQs

Question 5. How the yield from cultivation can be increased?
Answer:

Increase Of yield from cultivation:

Modern agronomy, plant breeding, agrochemicals such as pesticides and fertilizers, and technological improvements have sharply increased yields from cultivation.

Selective breeding and modern practices in animal husbandry have similarly increased the output of meat. Genetically modified organisms are an increasing component of agriculture, although they are banned in several countries.

Read And Learn More WBBSE Solutions For Class 8 School Science Short Answer Type Questions

Question 6. Name the major agricultural products.
Answer:

Major agricultural products:

The major agricultural products can be broadly grouped into food, fibers, fuels, and raw materials. Specific food includes cereals (grains), vegetables, fruits, oils, meats, and spices. Fibers include cotton, wool, hemp, silk, and flax. Raw materials include lumber and bamboo.

Other useful materials are produced by plants, such as resins, dyes, drugs, perfumes, biofuels, and ornamental products such as cut flowers and nursery plants.

Question 7. What is agronomy?
Answer:

Agronomy:

Agronomy is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation. Agronomy encompasses work in the areas of plant genetics, plant physiology, meteorology, and soil science.

Agronomy is the application of a combination of sciences like biology, chemistry, economics, ecology, earth science, and genetics.

Chapter 8 Human Food and Food Production Short Answer Questions

Question 8. What is horticulture?
Answer:

Horticulture:

Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and non-food crops such as grass and ornamental trees and plants.

It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance.

Question 9. What are crops and livestock?
Answer:

Crops And Livestock:

A crop is any cultivated plant, fungus, or alga that is harvested for food, clothing, livestock fodder, biofuel, medicine, or other uses. In contrast, animals that are raised by humans are called livestock, except those that are kept as pets.

Question 10. What is animal husbandry?
Answer:

Animal Husbandry:

Animal husbandry is the management and care of farm animals by humans for profit, in which genetic qualities and behavior, considered to be advantageous to humans, are further developed.

The term can refer to the practice of selectively breeding and raising livestock to promote desirable traits in animals for utility, sport, pleasure, or research.

Question 11. State the importance of the classification of crop plants.
Answer:

Importance of the classification of crop plants:

  1. To get acquainted with crops.
  2. To understand the requirement of soil and water for different crops.
  3. To know the adaptability of crops.
  4. To know the growing habit of crops.

Question 12. What are kharif crops and what are rabi crops?
Answer:

Kharif/Rainy/Monsoon crops:

The crops grown in monsoon months from June to Oct-Nov, require warm, wet weather at the major periods of crop growth, and also required short day lengths for flowering, e.g. cotton, rice, jowar, bajara etc.

Rabi/winter/cold seasons crops: Require winter season to grow well from Oct to March month. Crops grow well in cold and dry weather. Require longer day length for flowering, e.g. wheat, gram, sunflower, etc.

WBBSE Solutions For Class 8 School Science Long Answer Type Questions WBBSE Solutions For Class 8 School Science Short Answer Type Questions
WBBSE Solutions For Class 8 School Science Very Short Answer Type Questions WBBSE Solutions For Class 8 School Science Review Questions
WBBSE Solutions For Class 8 School Science Solved Numerical Problems WBBSE Solutions For Class 8 School Science Experiments Questions
WBBSE Solutions For Class 8 Maths WBBSE Class 8 History Notes
WBBSE Class 8 History Multiple Choice Questions WBBSE Solutions For Class 8 History
WBBSE Solutions For Class 8 Geography

 

Question 13. Write the differences between Kharif crops and rabi crops.
Answer:

Differences between Kharif crops and rabi crops:

Kharif Rabi
Season of sowing Rainy season Winter season
Cultivation period June to September October to March
Examples of such crops Paddy, maize and soybeans, pulses, and vegetables are grown during the summer Wheat, gram, pea, and mustard

 

Question 14. What is the preparation of soil for crop cultivation?
Answer:

Preparation of soil for crop cultivation:

The preparation of the soil is the first step before growing a crop. This involves turning the soil and loosening it so that roots can penetrate deep into the soil and also allows the roots to breathe easily.

Loosening of soil helps in the growth of earthworms and microbes which further loosens the soil and also adds humus to it.

Question 15. What is a plow?
Answer:

Plow:

Plough is being used since ancient times for tilling the soil, adding fertilizers to the crop, removing the weeds, scraping of soil, etc.

This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.). It contains a strong triangular iron strip called plowshare.

The main part of the plow is a long log of wood which is called a plow shaft. There is a handle at one end of the shaft. The other end is attached to a beam that is placed on the bulls’ necks.

One pair of bulls and a man can easily operate the plow. The indigenous wooden plow is increasingly being replaced by iron plows nowadays.

Question 16. What is a hoe?
Answer:

Hoe:

Hoe is a simple tool that is used for removing weeds and for loosening the soil. It has a long rod of wood or iron. A strong, broad, and bent plate of iron is fixed to one of its ends and works like a blade. It is pulled by animals.

Question 17. How good and damaged seeds for sowing can be identified?
Answer:

Good seeds can be separated from damaged ones by putting them into water. Damaged seeds are hollow and float on the water while good quality, healthy seeds settle at the bottom.

Question 18. What is a seed drill?
Answer:

Seed Drill:

A seed drill is a modern-day tool for sowing seeds and is used with the help of tractors. This tool has an edge over the traditional tool as it sows the seeds uniformly at proper distances and depths. It also covers the seeds with soil after sowing which prevents damage caused by birds. Seed drill saves time and labor.

WBBSE Class 8 Science Important Short Answers

Question 19. What is manure?
Answer:

Manure:

Manure is an organic substance obtained from the decomposition of plant or animal wastes. Farmers dump plant and animal waste in pits in open places and allow it to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.

Question 20. Why maturing is required for cultivation?
Answer:

Soil supplies mineral nutrients to the crop. These nutrients are essential for the growth of plants. Continuous growing of crops makes the soil poorer in certain nutrients.

Therefore, farmers have to add manure to the fields to replenish the soil with nutrients. This process is called manuring. Improper or insufficient manuring results in weak plants.

Question 21. What are fertilizers?
Answer:

Fertilizers:

Fertilizers are chemical substances that are rich in a particular nutrient. Fertilizers are produced in factories. Some examples of fertilizers are— urea, ammonium sulfate, superphosphate, potash, and NPK (Nitrogen, Phosphorus, and Potassium).

Question 22. Write the difference between manures and fertilizers.
Answer:

Difference between manures and fertilizers:

Fertiliser Manure
1. A fertilizer is an inorganic salt. Manure is a natural substance obtained by the decomposition of cattle dung, human waste, and plant residues.
2. A fertilizer is prepared in factories. Manure can be prepared in the fields.
3. A fertilizer does not provide any humus to the soil. Manure provides a lot of humus to the soil.
4. Fertilisers are very rich in plant nutrients like nitrogen phosphorus and potassium. Manure is relatively less rich in plant nutrients.

 

Question 23. What are the advantages of manures over _ fertilizers?
Answer:

The advantages of manures over _ fertilizers:

Organic manure is considered better than fertilizers. This is because

  1. It enhances the water-holding capacity of the soil.
  2. It makes the soil porous which exchange of gases becomes easy.
  3. It increases the number of friendly microbes.
  4. It improves the texture of the soil.

Question 24. What is irrigation? What are the sources of irrigation?
Answer:

Irrigation:

The supply of water to crops at different intervals is called irrigation. The sources of irrigation are— wells, tube wells, ponds, lakes, rivers, dams, and canals.

Question 25. What is a sprinkler system of irrigation?
Answer:

Sprinkler system of irrigation:

This system is more useful on uneven land where sufficient water is not available. The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals.

When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. The sprinkler is very useful for sandy soil.

Question 26. What is a drip system of irrigation?
Answer:

Drip system of irrigation:

In this system, the water falls drop by drop just at the position of the roots. So it is called a drip system. It is the best technique for watering fruit plants, gardens, and trees.

The system provides water to plants drop by drop. Water is not wasted at all. It is a boon in regions where the availability of water is poor.

Short Answer Questions for Class 8 Human Food

Question 27. State the importance of weeding.
Answer:

Importance of weeding:

Weeding is necessary since weeds compete with crop plants for water, nutrients, space, and light. Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings.

Question 28. What is a pest? Give example.
Answer:

Pest:

A pest is a plant or animal detrimental to humans or human concerns (such as agriculture or livestock production). Yellow stem borers are pests of paddy.

Question 29. What is the harvesting of crops?
Answer:

Harvesting of crops:

Harvesting a crop is an important task. The cutting of a crop after it is mature is called harvesting. In harvesting, crops are pulled out or cut close to the ground. It usually takes 3 to 4 months for a cereal crop to mature.

Question 30. What is the storage of crops? How this is done?
Answer:

Storage of crops:

Storage of crops is an important task. If the crop grains are to be kept for a longer time, they should be safe from moisture, insects, rats, and microorganisms. The fresh crop has more moisture.

If freshly harvested grains (seeds) are stored without drying, they may get spoilt or attacked by organisms, losing their germination capacity.

Hence, before storing them, the grains are properly dried in the sun to reduce their moisture in them. This prevents attack by insect pests, bacteria, and fungi.

Farmers store grains in jute bags or metallic bins. However, large-scale storage of grains is done in silos and granaries to protect them from pests like rats and insects.

Question 31. What are the different kinds of rice?
Answer:

Different kinds of rice:

There are four kinds of rice in our country. They are: ayus, aman, boro and IRRI. Ayus is sown in the month of baishakh and reaped in caravan or Bhadra.

Aman is sown in asar or sravan and reaped in agrarian or push. Boro is sown in winter and reaped in spring. IRRI is cultivated all year round.

Question 32. Write about the preparation of fields for paddy cultivation.
Answer:

Preparation of fields for paddy cultivation:

Paddy farmers get their fields ready before the rainy season. The weeds are cleared and the field is plowed by buffaloes or tractors to a depth of a few inches.

Manures and fertilizers are added to the soil. The whole surface is then covered with water of about 2.5 cm. The field is then made ready for receiving seedlings from the nursery.

Question 33. What is rice?
Answer:

Rice:

Rice is a kind of food grain. It is obtained from a plant called paddy. It is a one-time breeding plant. It grows up to two to three feet high. It feeds millions of people in the world. Rice is the seed of the grass species Oryza sativa.

Question 34. What is a mango?
Answer:

Mango:

Mango (Mangifera indica) belonging to Family Anacardiaceae is the most important commercially grown fruit crop in the country. Mango is the leading fruit crop of India and is considered to be the king of fruits.

Question 35. Write about the varieties of mango.
Answer:

Varieties of mango:

Though there are nearly 1000 varieties of mango in India, only the following varieties are grown in different states: Alphonso, Bangalore, Banganpalli, Bombai, Bombay Green, Dashehari, Fazli, Fernandin, Himsagar, Kesar, KishenBhog, Langra, Mankhurd, Mulgoa, Neelam, Samarbehist, Chausa, Suvarnarekha, Vanaraj, and Zardalu.

Recently some mango hybrids have been released for cultivation by different Institutes .. / Universities. These are — Mallika, Amrapali, Mangeera, Ratna, Arkaanmol, etc.

Question 36. Write about the irrigation of mango plants.
Answer:

Irrigation of mango plants:

Young plants are watered frequently for proper establishment. In the case of grown-up trees, irrigation at 10 to 15 days intervals from fruit set to maturity is beneficial for improving yield.

Question 37. Write about the North-Eastern Tea Belt of India.
Answer:

North-Eastern Tea Belt of India:

It is more or less a triangular area mainly in Assam and West Bengal. Assam is the largest producer of tea accounting for over 51 percent of the production and over 53 percent of the area under tea cultivation in India.

West Bengal is the second largest producer contributing over 22 percent of India’s tea from about one-fourth of the country’s total area under tea cultivation. The entire tea of West Bengal is produced in three northern districts Darjeeling, Jalpaiguri, and Coochbehar.

WBBSE Chapter 8 Human Food Study Guide

Question 38. What is pruning in tea plantations?
Answer:

Pruning in tea plantations:

It basically helps in maintaining the plant as a low bush in a phase of continuous vegetative growth. Pruning both stimulates and controls growth.

It removes dead, diseased, and overage wood, and thus helps rejuvenate bushes that have crossed the period • of maximum productivity.

Question 39. What is meant by tea testing?
Answer:

Tea Testing:

Tea testing is the process in which a trained taster determines the quality of a particular tea. Due to climatic conditions, topography, manufacturing process,

And different clones of the Camellia sinensis plant (tea), the final product may have vastly different flavors and appearances. These differences can be tasted by a trained taster in order to ascertain the quality prior to sale or possibly blending tea.

Question 40. Write the scientific names of honeybees.
Answer:

Scientific names of honeybees:

Four important species of honeybees are as follows.

  1. The rock bee, Apis dorsata.
  2. The Indian hive bee, Apis Serena indicia.
  3. The little bee, Apis florea.
  4. The European or Italian bee, Apis mellifera.

Question 41. What are the casts of a honeybee colony?
Answer:

Casts of a honeybee colony:

Honeybee is a social insect. The nest of the honey bee is known as a bee hive. A hive in summer consists of 32 to 50 thousand individuals, depending on the locality.

The members of honeybees are of three castes namely the queen bee, the worker bee, and the drone bee. All three types depend on each other for their existence. There is normally one queen, 10,000 to 30,000 workers, and a few hundred drones in a colony.

Question 42. What are the products of a bee hive?
Answer:

Products of a bee hive:

Honey has been treasured as one of the nature’s most perfect food. Other than honey, the products such as bee wax, bee venom, propolis, royal jelly, and pollen are obtained as bee-hive products.

Question 43. What is mariculture?
Answer:

Mariculture:

Mariculture involves the cultivation of only marine organism, unlike any aquatic organism. This is the method of fish farming which is done usually on a very broader scale by forming an enclosed section of the ocean.

Question 44. What is capture fishery?
Answer:

Capture fishery:

The process of obtaining fish from natural resources like lakes, rivers, ponds, etc. is called capture fishing. Capture fisheries are the exploitation of aquatic organisms without stocking the seed.

Recruitment of the species occurs naturally. This is carried out in the sea, rivers, reservoirs, etc. Fish yield decreases gradually in capture fisheries due to indiscriminate catching of fish including brooders and juveniles.

Question 45. What is culture fishery?
Answer:

Culture Fishery:

The production of fish in a given body of water such as ponds, lakes or reservoirs using scientific methods of feeding, breeding, etc., so as to enhance the output is called culture fishing.

A culture fishery is the cultivation of selected fishes in confined areas with utmost care to get maximum yield. The seed is stocked, nursed, and reared in confined waters, and then the crop is harvested.

Culture takes place in ponds, which are fertilized, and supplementary feeds are provided to fish to get maximum yield. In order to overcome the problems found in capture fisheries to increase production, considerable attention is given to cultural fisheries.

Question 46. What is an inland fishery?
Answer:

Inland fishery:

Inland waters are aquatic-influenced environments located within land boundaries. This includes those located in coastal areas, even those adjacent to marine environments.

Inland water systems can be fresh, saline, or a mix of the two (brackish water). Inland resources comprise rivers and canals, estuaries, floodplains, wetlands, latfbons, and reservoirs.

While the marine water bodies are used mainly for capturing fisheries resources, the inland water bodies are widely used both for culture and capture fisheries.

Question 47. What are nursery ponds?
Answer:

Nursery ponds:

Nursery ponds are constructed to rear carp fry or larvae. A normal sized nursery pond measures 5 x 10 m, with a depth of 0.5 m. Before filling up the water the pond should be cleaned thoroughly to get rid of predators and parasites that may be destructive to the larvae. About 1,500 to 3,000 fries can be stocked in the nursery pond.

Question 48. What is poultry farming?
Answer:

Poultry farming:

Poultry farming is the raising of domesticated birds such as chickens, ducks, turkeys, and geese, for the purpose of farming meat or eggs for food. Poultry is farmed in great numbers with chickens being the most numerous.

Question 49. What are broilers?
Answer:

Broilers:

A young bird of either sex, usually of meat-type breeds up to 8-10 weeks of age and weighing 1.5-2.5kg. The term broiler is applied to chicks that have especially been bred for rapid growth.

  1. Broiler strains are based on hybrid crosses between Cornish White, New Hampshire, and White Plymouth Rock. In broiler production there are two main production phases:
  2. keeping of parent stock and production of day-old-chicken and
  3. growing and finishing of broilers.

Question 50. What are layers in poultry?
Answer:

Layers in poultry:

Layers are efficient egg producers. Breeds used for egg production in the industrial production system are almost entirely based on the White Leghorn and Rhode Island Red.

Selection and crossbreeding techniques have resulted in productive laying hens producing 15 – 19 kg of eggs per year. In layer production, sometimes two phases of production are recognized: (1) the growing phase up to approximately 140 days; and (2) the productive phase from 140 – 560 days.

Short Answer Resources for Class 8 Human Food

Question 51. Classify fowl breeds according to their utility.
Answer:

Fowl breeds are of the following three types, according to their utility-

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Example-Rhode Island Red, New Hampshire, etc.

Question 52. Classify fowl breeds according to their brood ness.
Answer:

Fowl breeds are of the following two types, according to their broodiness-

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

Non-sitter: The mothers do not sit on their eggs. Eggs are generally incubated in artificial incubator machines. Examples- Leghorn, Minorca, etc.

Question 53. Write the advantages of the deep litter system of poultry farming.
Answer:

Advantages of the deep litter system of poultry farming:

  1. It is economical.
  2. Hygienic, comfortable, and safe for birds.
  3. Controls diseases and vices.
  4. It increases the efficiency of production.

Materials such as paddy husks saw dust, dried leaves, chopped straw, and groundnut kernels depending upon the availability can be used as litter materials.

Question 54. Write the nutritional value of a poultry egg.
Answer:

Nutritional value of a poultry egg:

  1. Contains one of the highest quality proteins of any food.
  2. A large egg contains about 70 calories and 6 grams of protein.
  3. A single egg contains 13 essential nutrients like vitamins, minerals, etc.
  4. Egg proteins contain time-release energy which helps maintain blood glucose levels and makes people feel full and energized longer.

Question 55. Write the differences between major carp and minor craps.
Answer:

The differences between major carp and minor craps:

Major carp Minor carp
1. Relatively large in size (90-120cm). 1. Relatively small in size (10-30cm).
2. Higher growth rate. 2. Lower growth rate.
3. The number of scales along the lateral line is more than 35. 3. The number of scales along the lateral line is 26-35.
4. Economically more important. 4. Economically less important.

 

Question 56. Mention the precautions that need to be taken while sowing the seeds.
Answer:

The following precautions should be taken while sowing seeds in the soil:

  1. The seeds should be sown at the right depth in the soil suitable for germination.
  2. The seeds should be sown at the right intervals or spacings.
  3. The seeds should never be sown in dry soil.
  4. The seeds should not be sown in highly wet soil.

Question 57. Excessive use of fertilizers is harmful to the soil-explain.
Answer:

Excessive use of fertilizers is harmful due to the following reasons:

Excessive use of fertilizers changes the chemical nature of the soil and makes the soil less fertile. Excessive use of fertiliser can turn soil highly acidic or alkaline.

The excessive use of fertilizers causes water pollution in ponds, lakes, rivers, etc.

Question 58. Mention the advantages of crop rotation. Rotation of crop has the following advantages:
Answer:

Advantages of crop rotation:

It improves the fertility of the soil by replenishing it with nitrogen and hence brings about an increase in the production of food grain. The rotation of crops saves a lot of nitrogenous fertilizers.

Question 59. Why is irrigation necessary for agriculture?
Answer:

  1. Irrigation is necessary because-
  2. Irrigation before plowing makes the soil soft which makes plowing easier.
  3. It is necessary to provide moisture for the germination of seeds.
  4. Water is necessary for healthy crop growth and for the absorption of nutrients.

WBBSE Class 8 Science Practice Questions on Food Production

Question 60. What are the economic utilities of exotic breeds of poultry?
Answer:

Economic utilities:

  1. Exotic breeds are good layers of large-sized eggs.
  2. They yield more meat or flesh.
  3. They heed less feed for maintenance.

Question 61. What is the nutritional value of mango?
Answer:

Nutritional value of mango:

Mango contains protein, fat, carbohydrate, flavonoids, and minerals like Ca, P. Fe, etc. It also contains vitamins A, B, C, E, and K in good quantities. It treats skin pores and adds a glow to the skin.

Question 62. Give a word diagram of the life cycle of the honeybee
Answer:

Life cycle of the honeybee:

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production life cycle of honey bee

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production VSAQs

Chapter 8 Human Food And Food Production Answer in One or Two sentences

Question 1. Where do we obtain our food?
Answer:

We obtain our food from plants and animal, resources.

Question 2. What is the name of the branch of science which deals with the process of food production?
Answer:

The branch of science is agriculture.

Question 3. Name two plant resources that we consume as food.
Answer:

These are rice, wheat, etc.

Question 4. Name two animal resources that we consume as food.
Answer:

These are milk, egg, meat, etc.

Question 5. What is a crop?
Answer:

Crop:

When the same plant is cultivated in a large area, it is collectively termed a crop.

Read And Learn More WBBSE Solutions For Class 8 School Science Very Short Answer Type Questions

Question 6. Name two cereal crops.
Answer:

Two cereal crops:

These are paddy, wheat, etc.

Question 7. Name two tuber crops.
Answer:

Two tuber crops:

These are potatoes, ginger, etc.

Question 8. Name two sugar crops.
Answer:

Two sugar crops:

These are sugarcane and beet.

WBBSE Class 8 School Science Chapter 8 Human Food And Food Production VSAQs

Question 9. Name two medicinal crops.
Answer:

Two medicinal crops:

These are tulsi, sharp, etc.

Question 10. Name two decorative plants.
Answer:

Two decorative plants:

These are cactus, bougainvillea, etc.

Question 11. What are Kharif crops?
Answer:

Kharif crops:

The crops whose cultivation depends upon monsoon are called Kharif crops. Examples- Paddy, Maize, Cotton, etc.

WBBSE Solutions For Class 8 School Science Long Answer Type Questions WBBSE Solutions For Class 8 School Science Short Answer Type Questions
WBBSE Solutions For Class 8 School Science Very Short Answer Type Questions WBBSE Solutions For Class 8 School Science Review Questions
WBBSE Solutions For Class 8 School Science Solved Numerical Problems WBBSE Solutions For Class 8 School Science Experiments Questions
WBBSE Solutions For Class 8 Maths WBBSE Class 8 History Notes
WBBSE Class 8 History Multiple Choice Questions WBBSE Solutions For Class 8 History
WBBSE Solutions For Class 8 Geography

 

Question 12. What are rabi crops?
Answer:

Rabi crops:

The winter season crops, whose cultivation does not depend upon monsoon, are called rabi crops. Examples – Wheat, Barley, Mustard, etc.

Question 13. What is the medium of germination of seed?
Answer:

Medium of germination of seed:

Generally, soil is the medium for the germination of seeds.

Question 14. Mention one reason for turning off the soil before sowing of seed.
Answer:

The soil will become loose and the roots of plants will easily penetrate into it.

Chapter 8 Human Food and Food Production WBBSE Answers

Question 15. Does Sandy soil need frequent irrigation?
Answer:

Due to the poor water retaining capacity Of sandy soil, the crops cultivated in sandy soil need frequent irrigation.

Question 16. Why earthworm is considered a ‘farmer’s friend’?
Answer:

The earthworm present in the soil, help in loosening the soil and increase the organic content or humus of soil.

Question 17. Name a soil bacteria, which helps in agriculture.
Answer:

Rhizobium is a soil bacteria that helps in agriculture.

Question 18. Name the tools for plowing.
Answer:

Tools for plowing:

These are plow, hoe, cultivator, etc.

Question 19. How a good seed can be identified for sowing?
Answer:

Good healthy seeds sink in water but spoiled seeds float on the water’s surface.

Question 20. Name an instrument for sowing seeds in the soil.
Answer:

A seed drill can be used for sowing seeds.

WBBSE Class 8 Science Very Short Answer Format

Question 21. Name one macronutrient and one micronutrient of soil, required for plant growth.
Answer:

Macronutrient is carbon and micronutrient is iron.

Question 22. How organic manures are produced in soil?
Answer:

Organic manures are produced by the decomposition of dead animals, plants, and their wastes.

Question 23. What are inorganic fertilizers?
Answer:

Inorganic fertilizers:

Inorganic fertilizers are chemical substances required for plant growth. Example- superphosphate.

Question 24. Mention one advantage of organic manure over inorganic fertilizer.
Answer:

Organic manure helps the growth of beneficial bacteria in soil, while excess inorganic fertilizer may reduce them.

Question 25. What is crop rotation?
Answer:

Crop rotation:

In crop rotation, different crops are raised from some land, at different seasons.

Question 26. What is the benefit of crop rotation?
Answer:

Benefit of crop rotation:

It replenishes the soil nutrients used during cultivation.

Question 27. What is irrigation?
Answer:

Irrigation:

Irrigation is the method of water supply to crop fields.

Question 28. Name two sources of irrigation.
Answer:

Two sources of irrigation:

Generally water from rivers, canals, tube wells, etc. is used for irrigation.

Question 29. What are weeds?
Answer:

Weeds:

Weeds are undesirable vegetation in a crop field.

Question 30. Name a chemical used to destroy weeds.
Answer:

Examples of weedicides are – Dalapon, 2, 4- D(2, 4-Dichlorophenoxyacetic acid).

WBBSE Class 8 Science Important Very Short Answers

Question 31. What is an insecticide? Give an example.
Answer:

Insecticide:

The chemicals Which kill insects are known as insecticides. Examples are DDT, BHC, etc.

Question 32. What is biological control of pests?
Answer:

Biological control of pests:

The process by which pest organisms are controlled by other organisms, which may be their predator or parasite and also at the same time harmless for humans, is known as biological control

Question 33. Are the terms insecticides and pesticides synonymous?
Answer:

Pesticides and insecticides are not synonymous. Insecticide destroys only insects but pesticides will kill any pest, which may or may not be an insect. For example, rat-killing poison is a pesticide but not an insecticide.

Question 34. What are silos?
Answer:

Silos:

Silos are airtight chambers for storing food grains.

Question 35. Why nitrogen gas is circulated through grannies?
Answer:

Pests can not survive in a medium containing high nitrogen.

Question 36. State the utility of rice bran.
Answer:

Utility of rice bran:

Oil is produced from rice bran.

Question 37. Name the winter paddy and summer paddy.
Answer:

Winter paddy is known as a man; summer paddy Is known as boro.

Question 38. What is golden rice?
Answer:

Golden Rice:

It is a special type of rice containing high vitamin-A. Agricultural scientists have created this variety.

Very Short Answer Questions for Class 8 Human Food

Question 39. What amount of standing water in the field is needed for paddy cultivation?
Answer:

About 30-50 mm of standing water is needed.

Question 40. Which fruit is considered the king of fruits?
Answer:

Mango is considered the king of fruits.

Question 41. To which country, mango is indigenous?
Answer:

Mango is indigenous to India.

Question 42. Name the common vitamins found in mango.
Answer:

Mango contains vitamins A, B complex, and C.

Question 43. Name the varieties of mangoes of West Bengal which mature first and last in a season.
Answer:

Golapkhas matures first and Jhumkophajli matures last.

Question 44. What is the most common way of grafting of mango plant, for its propagation?
Answer:

Anarching is the most common way of mango grafting.

Question 45. Name two states of India, whose tea production is maximum.
Answer:

In India maximum tea grows in Assam and West Bengal.

Question 46. Name two substances present in tea, which stimulate our body.
Answer:

These two substances are caffeine and pantothenic acid.

Question 47. What is special about green tea?
Answer:

Green Tea:

Green tea contains vitamin K which prevents internal hemorrhages, myocardial infarction, rheumatic inflammations, etc.

Question 48. Write about the propagation of tea plants.
Answer:

Propagation takes place from seeds or by single node cuttings.

WBBSE Class 8 Science Study Guide Human Food

Question 49. What parts of tea plants are used for tea manufacture?
Answer:

Generally one bud and two or three leaves are used.

Question 50. Where do natural beehives develop?
Answer:

Beehives generally remain suspended from trees and crevices or cornices of houses.

Question 51. Name the different casts of a bee colony.
Answer:

Different casts are—queen, male or drone, and workers.

Question 52. How do the worker bees produce honey?
Answer:

Worker bees produce honey by mixing the nectar of flowers with their saliva.

Question 53. Name the life cycle stages of honeybees.
Answer:

The life cycle stages are— egg, larva, pupa, and adult.

Question 54. Why apiary is to be established near flower-erring plants.
Answer:

Because worker bees collect nectar from flowering plants

Question 55. What is Fishery?
Answer:

Fishery:

Fishery is the culture and capture of economically important aquatic animals like fish, prawns, pearls, etc.

Question 56. What is pisciculture?
Answer:

Pisciculture:

Pisciculture is the culture and capture of fish.

Question 57. What is a fish?
Answer:

Fish:

True fish is a red-blooded vertebrate animal.

Question 58. What are carps?
Answer:

Carps:

Carps are freshwater edible, toothless bony fishes, that have swim bladders and body (except the head region) covered with scales.

Question 59. What are spawns?
Answer:

Spawns:

Sperms and eggs of fishes unite to produce spawns.

Question 60. What is fry?
Answer:

Fry:

The fishlings, released from fertilized eggs, up to the length of 25 – 40 mm are called fry.

Question 61. What are fingerlings ?
Answer:

Fingerlings:

These are small fishlings up to the size of 40 – 100 mm.

Question 62. Name the Indian major carps used in composite fish culture.
Answer:

These are rohu, mrigel and katla.

Human Food and Food Production WBBSE Resources

Question 63. Where in Kolkata, large scale sewage-fed fish culture performed?
Answer:

It is performed in the berries in East Kolkata.

Question 64. What are poultry birds?
Answer:

Poultry Birds:

Economically important birds are known as poultry birds. Examples—Fowls, Ducks, etc.

Question 65. Give an example of the light, non-sitter fowl breed.
Answer:

Leghorn is a light, non-sitter fowl breed.

Question 66. Give an example of the heavy, sitter poultry breed.
Answer:

Brahma is a heavy, sitter poultry breed.

Question 67. What is a broiler?
Answer:

Broiler:

Broiler is a type of hybrid fowl, created mainly for obtaining meat.

Question 68. What is intercropping?
Answer:

Intercropping:

The practice of growing two or more crops simultaneously on the same field in a definite pattern is called intercropping.

Question 69. Name two diseases of honey bees.
Answer:

Two diseases of honey bees:

Nosema and Acarine disease.

Question 70. What is the role of polyphenols present in tea?
Answer:

Polyphenols present in tea reduces blood cholesterol and helps to prevent cancer due to their antioxidant property.

WBBSE Class 8 Quick Answers on Food Production

Question 71. Which type of carp is punti?
Answer:

Minor carp.

Question 72. Name the vitamin contained in the egg.
Answer:

Eggs are rich in vitamins A, D, E, and B-com- plex.

Question 73. Mention a modern feature that is employed in the storage of food grains.
Answer:

Nitrogen gas is continuously circulated inside silos to prevent pests.

Question 74. What is polyculture?
Answer:

Polyculture:

Polyculture of fishes employs scientific fish farming where several species of fish (both local and imported) are cultured at the same time in the same pond.

Question 75. Mention some desirable agronomic characteristics of fodder crops.
Answer:

Profuse branching and tallness.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Review Questions

Chapter 8 Human Food And Food Production Review Questions  MCQs

Question 1. We obtain food indirectly from

  1. Plants
  2. Animals
  3. Soil
  4. Air

Answer: 3. Soil

Question 2. Which of the following is not a cereal crop?

  1. Cotton
  2. Paddy
  3. Wheat
  4. All of these

Answer: 1. Cotton

Question 3. Fibre crop is

  1. Peas
  2. Jute
  3. Potato
  4. Soya bean

Answer: 2. Jute

Question 4. Crops may be

  1. Animals
  2. Plants
  3. Both animals and plants
  4. None of these

Answer: 3. Both animals and plants

Read And Learn More WBBSE Solutions For Class 8 School Science Review Questions

Question 5. Which of the following is not a plantation crop?

  1. Ginger
  2. Tea
  3. Coffee
  4. Coconut

Answer: 1. Ginger

Question 6. Fruit cultivation comes under

  1. Horticulture
  2. Apiculture
  3. Pisciculture
  4. Sericulture

Answer: 1. Horticulture

Question 7. Excess fertilizer leads to

  1. Soil pollution
  2. Water pollution
  3. Air pollution
  4. All of these

Answer: 2. Water pollution

WBBSE Solutions For Class 8 School Science Long Answer Type Questions WBBSE Solutions For Class 8 School Science Short Answer Type Questions
WBBSE Solutions For Class 8 School Science Very Short Answer Type Questions WBBSE Solutions For Class 8 School Science Review Questions
WBBSE Solutions For Class 8 School Science Solved Numerical Problems WBBSE Solutions For Class 8 School Science Experiments Questions
WBBSE Solutions For Class 8 Maths WBBSE Class 8 History Notes
WBBSE Class 8 History Multiple Choice Questions WBBSE Solutions For Class 8 History
WBBSE Solutions For Class 8 Geography

 

Question 8. Weeds affect crop plants by

  1. Killing plants in fields before they grow
  2. Dominating the plants to grow
  3. Competing for various resources of crops causing low availability of nutrients
  4. All of these

Answer: 3. Competing for various resources of crops causing low availability of nutrients

Question 9. Kharif crops generally grow during

  1. Summer
  2. Winter
  3. All year round
  4. Spring

Answer: 1. Summer

Question 10. Which of the following is not a rabi crop?

  1. Gram
  2. Mustard
  3. Maize
  4. Sunflower

Answer: 3. Maize

Question 11. Agricultural practice includes

  1. Sowing of seed
  2. Irrigation
  3. Both sowing of seeds and irrigation
  4. Storage of crops

Answer: 3. Both sowing of seeds and irrigation

Question 12. Vermicompost means

  1. Manure prepared from cattle excreta, firm litter, etc.
  2. Manure is prepared by using earthworms to speed up decomposition
  3. Manure prepared chemically
  4. Manure is prepared by mulching plants in the soil

Answer: 2. Manure prepared by using earthworms to speed up decomposition

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Review Questions

Question 13. Which animal is considered a farmer’s friend?

  1. Dog
  2. Earthworm
  3. Cow
  4. Pests

Answer: 4. Pests

Question 14. Plant and animal bodies in soil are decomposed by

  1. Bacteria
  2. Protozoa
  3. Virus
  4. Earthworm

Answer: 1. Bacteria

Question 15. Topsoil is used for

  1. Growth of plant
  2. Growth of animals
  3. Building Construction
  4. Water conservation

Answer: 1. Growth of plant

Question 16. Which is not used in turning and loosening of soil?

  1. Plough
  2. Tractor
  3. Seed drill
  4. Hoe

Answer: 3. Seed drill

Question 17. Plant micronutrient is

  1. Carbon
  2. Iron
  3. Nitrogen
  4. Calcium

Answer: 4. Calcium

Chapter 8 Human Food and Food Production Resources

Question 18. Which of the following cannot be provided to the soil by a chemical fertilizer?

  1. Nitrogen
  2. Humus
  3. Potassium
  4. Phosphorus

Answer: 2. Humus

Question 19. Are the rhizobium bacteria present in the root nodules of pea plants can fix which of the following from the atmosphere?

  1. Hydrogen
  2. Halogen
  3. Oxygen
  4. Nitrogen

Answer: 4. Nitrogen

  1. Question 20. Which is not an inorganic fertilizer?
  2. Nitrogen
  3. Potassium
  4. Superphosphate
  5. Compost

Answer: 4. Compost

Question 21. The acidity of the soil may be increased by

  1. (Nh4)2s04
  2. Nan02
  3. Naci
  4. All of these

Answer: 1. (Nh4)2s04

Question 22. An abiotic factor that affects crop production is

  1. Cattle
  2. Soil nature
  3. Rodents
  4. Pathogenic microbes

Answer: 2. Soil nature

Question 23. The process of removing unwanted plants from a crop field is called

  1. Harvesting
  2. Transplanting
  3. Branding
  4. Weeding

Answer: 4. Transplanting

Question 24. Replenishment of soil nutrients is helped by

  1. Crop rotation
  2. Irrigation
  3. Plowing
  4. Sowing

Answer: 1. Crop rotation

Question 25. The water content of the plant body is about

  1. 60%
  2. 70%
  3. 90%
  4. 10%

Answer: 3. 90%

Question 26. The process of water supply to the crop field is known as

  1. Plowing
  2. Drilling
  3. Irrigation
  4. Weeding

Answer: 3. Irrigation

Question 27. The traditional method of irrigation of crop fields is done by

  1. Drip system
  2. Dhekli method
  3. Sprinkler system
  4. Canal system

Answer: 2. Dhekli method

Question 28. Which of the following is not a weed?

  1. Paddy
  2. Grass
  3. Chenopodium
  4. Wild oat

Answer: 1. Paddy

Question 29. Which of the following is not a pest?

  1. Locust
  2. Cow
  3. Rat
  4. Leaf hoppers

Answer: 2. Cow

Question 30. Pests are

  1. Insects
  2. Harmful organisms
  3. Used for cleaning teeth
  4. Manures

Answer: 2. Harmful organisms

Question 31. Chemical control of pests may be done by

  1. Birds
  2. Ddt
  3. Sodium nitrate
  4. Hand pulling

Answer: 2. Ddt

Question 32. Control of pests by using other organisms is known as

  1. Biological control
  2. Physical control
  3. Chemical control
  4. Mechanical control

Answer: 1. Biological control

WBBSE Class 8 Science Important Review Questions

Question 33. Which is not a method of harvesting crops?

  1. Threshing
  2. Winnowing
  3. Storage
  4. All of these

Answer: 3. Storage

Question 34. Ifor storage, the crops must be free from

  1. Moisture
  2. Air
  3. Soil
  4. All of these

Answer: 1. Moisture

Question 35. Which is not a variety of paddy?

  1. Jaya
  2. Leghorn
  3. Ratna
  4. |Rr|

Answer: 2. Leghorn

Question 36. Boro paddy grows during

  1. Autumn
  2. Winter
  3. Summer
  4. Spring

Answer: 3. Summer

Question 37. What type of paddy is Ratna?

  1. Jaldi
  2. Majhasi
  3. Nabi
  4. None of these

Answer: 1. Jaldi

Question 38. Golden rice is rich in

  1. Vitamin a
  2. Vitamin c
  3. Vitamin d
  4. All of these

Answer: 1. Vitamin a

Question 39. A Seedbed of aman paddy is prepared during

  1. July-august
  2. June-July
  3. December-January
  4. March-April

Answer: 2. June-july

Question 40. Paddy grows properly in

  1. Dry field
  2. Wet field
  3. Field slightly submerged underwater
  4. Sandy field

Answer: 3. Field slightly submerged underwater

Question 41. Mango cultivation is facilitated by

  1. Rainfall
  2. Mist
  3. Sunlight
  4. High wind

Answer: 3. Sunlight

Question 42. Which type of soil is not suitable for mango cultivation?

  1. Alluvial soil
  2. Loamy soil
  3. Sandy soil
  4. Laterite soil

Answer: 3. Sandy soil

Question 43. Which variety of mango is not generally found in west Bengal?

  1. Alfonso
  2. Himsagar
  3. Golapkhas
  4. None of these

Answer: 1. Alfonso

Question 44. Mango is best propagated through

  1. Feed
  2. Grafting
  3. Fruit
  4. Seed

Answer: 2. Grafting

WBBSE Class 8 Science Practice Questions on Food Production

Question 45. Mango buds generally develop during

  1. December – January
  2. July – august
  3. October – November
  4. March – April

Answer: 1. December – January

Question 46. One of the largest tea-producing countries is

  1. Japan
  2. India
  3. Austalia
  4. America

Answer: 2. India

Question 47. Tea contains

  1. Caffeine
  2. Morphin
  3. Rennin
  4. None of these

Answer: 1. Caffin

Question 48. In India maximum tea is produced by

  1. West Bengal
  2. Kerala
  3. Assam
  4. Karnataka

Answer: 3. Assam

Question 49. Worker honeybees fan the honey chambers of their beehive by

  1. Legs
  2. Wings
  3. Head
  4. Abdomen

Answer: 2. Wings

Question 50. The culture of honeybees is known as

  1. Sericulture
  2. Pisciculture
  3. Apiculture
  4. Horticulture

Answer: 3. Apiculture

Question 51. An exotic variety of honeybee is

  1. Apis indica
  2. Apis dorsata
  3. Apis florea
  4. Apis mellifera

Answer: 4. Apis mellifera

Question 52. Capture fishery is performed in

  1. Lake
  2. Pond
  3. Sea
  4. All of these

Answer: 3. Sea

Question 53. Which of the following is not a carp?

  1. Rohu
  2. Koi
  3. Katla
  4. Bata

Answer: 2. Koi

Question 54. Bata fish is an example of

  1. Major carp
  2. Minor carp
  3. Exotic carp
  4. None of these

Answer: 2. Minor carp

Question 55. Which is the correct order?

  1. Spawn fry fingerling
  2. Fry spawn fingerling
  3. Fingerling spawn fry
  4. Fingerling fry spawn

Answer: 1. Spawn fry fingerling

Question 56. Sewage-fed fish culture is performed in

  1. Pond
  2. Sea
  3. Wastewater
  4. Irrigated water

Answer: 3. Wastewater

Question 57. The breeds hens of which incubate their eggs are known as

  1. Incubator
  2. Sitter
  3. Layer
  4. Broiler

Answer: 2. Sitter

Question 58. A battery cage is used for rearing

  1. Fowls
  2. Fishes
  3. Honeybee
  4. Pests

Answer: 1. Fowls

Question 59. The term deep litter is associated with

  1. Dairy
  2. Apiary
  3. Poultry
  4. Farming

Answer: 3. Poultry

 

Chapter 8 Human Food And Food Production Fill In The Blanks

Question 1. Paddy, and wheat are examples of ___________ crops.
Answer: Cereal

Question 2. Cotton and jute are examples of ___________ crops.
Answer: Fibre

Question 3. Tea and coffee are examples of ___________ crops.
Answer: Plantation

Question 4. Fruit and vegetable culture are included in the branch of agriculture, known as ___________.
Answer: Horticulture

Question 5. Summer crops are known as ___________ crops.
Answer: Kharif

Question 6. Rabi crops grow during___________.
Answer: Winter

Question 7. Soil aeration may be caused by ___________the soil.
Answer: Loosening

Question 8. ___________ are considered as farmer’s friends.
Answer: Earthworms

Question 9. Humus is the ___________ content of the soil.
Answer: Organic

Question 10. Only___________ soil help in the growth of plants.
Answer: Top

Question 11. The process of turning the soil is known as ___________.
Answer: Plowing

Question 12. a___________ attached with tractor help in ploughing.
Answer: Cultivator

Question 13. Nowadays___________ is used to sow the seeds.
Answer: Seed drills

Question 14. Organic manure is produced by ___________ of dead organisms.
Answer: Decomposition

Question 15. Ammonium sulfate increases the ___________ of soil.
Answer: Acidity

Human Food WBBSE Study Guide

Question 16. Sodium nitrate can ___________ the alkalinity of the soil.
Answer: Increases

Question 17. Root nodules of leguminous plants contain the bacteria ___________.
Answer: Rhizobium

Question 18. Irrigation helps in the supply of ___________ to the croplands.
Answer: Water

Question 19. Rats, locusts, and termites are considered as ___________ of crops.
Answer: Pests

Question 20. Some fungi produce___________ disease in potato.
Answer: Blight

Question 21. Pests may be quickly eliminated by ___________ control.
Answer: Chemical

Question 22. Control of pests by another organism, harmless to humans, is known as ___________ control.
Answer: Biological

Question 23. Granaries are used for___________ of food grains.
Answer: Storge

Question 24. ___________ paddy grows during autumn.
Answer: Aush

Question 25. Bhasamanik is a type of ___________ paddy.
Answer: Aman

Question 26. Golden rice is rich in vitamin ___________
Answer: A

Question 27. Mango is ___________ to India.
Answer: Indigenous

Question 28. Himsagar is a variety of ___________.
Answer: Mango

Question 29. Tea contains the stimulant ___________
Answer: Caffeine

Question 30. The tea-producing plant belongs to the genus ___________
Answer: Camellia

Question 31. Application of ___________ fertilizers increases the production of tea leaves.
Answer: Nitrogenous

Question 32. Eggs in bee colony are laid by ___________ bee
Answer: Queen

Question 33. Male honeybees are also called ___________.
Answer: Drones

Question 34. Worker honeybees have wax glands in their ___________
Answer: Abdomen

Question 35. Bees produce honey by mixing saliva with ___________
Answer: Nector

Question 36. The stages of the life cycle of a honeybee are egg, larva, ___________, and adult.
Answer: Pipa

Question 37. The culture of honeybees is known as ___________
Answer: Apiculture

Question 38. Mass movement of honeybees is known as___________
Answer: Swarming

Question 39. Pisciculture deals with the culture of ___________
Answer: Fishes

Question 40. Scales are absent on the ___________ of carps.
Answer: Head

Question 41. The fish tilapia is exotic but not a ___________
Answer: Carp

Question 42. Fish sperms and eggs unite to produce ___________
Answer: Spaws

Question 43. The culture of different types of carp in a pond is known as ___________ fish culture.
Answer: Composite

Question 44. The sewage-fed fishery is observed in the ___________ of East Kolkata.
Answer: Bheris

Question 45. Based on economic usefulness the fowl breeds may be-laying breed, ___________ breed, and dual breed.
Answer: Table

Question 46. Broilers are created for obtaining ___________.
Answer: Meat

Question 47. Deep method is used in poultry,___________
Answer: Litter

 

Chapter 8 Human Food And Food Production Identify As ‘True Or False

Question 1. Horticulture deals with the cultivation of fruits, vegetables, flowers, and decorative plants.
Answer: True

Question 2. Crops are plants of different kinds cultivated in a large area.
Answer: False

Question 3. Peas and beans are cereal crops.
Answer: False

Question 4. Rubber is a plantation crop.
Answer: True

Question 5. Cabbage is a flower.
Answer: False

Question 6. Groundnut is a Kharif crop.
Answer: True

Question 7. Kharif crops are dependent on monsoon.
Answer: True

Question 8. Maize is a rabi crop.
Answer: False

Question 9. Humus is the organic content of the soil.
Answer: True

Question 10. A seed drill is used for plowing.
Answer: False

Question 11. Hoe is used for sowing seeds.
Answer: False

Question 12. The tractor remains attached behind cultivator.
Answer: False

Question 13. Spoilt seeds float on water.
Answer: True

Question 14. Zinc is a macronutrient present in the soil.
Answer: False

Question 15. Co Jv dung is organic manure.
Answer: True

Review Questions for Class 8 Human Food and Production

Question 16. Superphosphate is inorganic fertilizer.
Answer: True

Question 17. Inorganic fertilizers are better than organic manure.
Answer: False

Question 18. Crop rotation is turning a crop upside down.
Answer: False

Question 19. Organic manures increase the water retention capacity of the soil.
Answer: True

Question 20. Irrigation means plowing a crop field.
Answer: False

Question 21. Weeds are unimportant plants in crop fields.
Answer: True

Question 22. Grass is a type of weed.
Answer: True

Question 23. A stem borer is an instrument used to cut a stem.
Answer: False

Question 24. Chemical control of pests is effective but harmful.
Answer: True

Question 25. Insecticides may pollute the water of rivers.
Answer: True

Question 27. Rice contains only carbohydrates and no protein.
Answer: False

Question 28. Basmati is push-type rice.
Answer: False

Question 29. Boro paddy is harvested in April-May.
Answer: True

Question 30. Mango is cultivated only in India.
Answer: False

Question 31. High rainfall is useful for mango cultivation.
Answer: False

Question 32. Himsagar mango is found only in West Bengal.
Answer: False

Question 33. Grafting of the mango tree is done from July – August.
Answer: True

Question 34. In the case of mango, it takes about two months for ripe fruits to be produced after flowering.
Answer: False

Question 35. Tea is cultivated on the slopes of hills.
Answer: True

Question 36. Tea may cause an increase in blood cholesterol.
Answer: False

Question 37. The Fluoride content of tea may cause bone decay.
Answer: False

Question 38. Tea plants belong to the genus Camellia.
Answer: True

Question 39. Tea plants may propagate both from seeds and plant parts.
Answer: True

Question 40. We get honey and wax from bee hives.
Answer: True

Question 41. Worker honeybees lay eggs.
Answer: False

Question 42. Worker honeybees have wax glands on their head.
Answer: False

Question 43. Apiculture is the first step of honeybee culture.
Answer: False

Question 44. The honey bee Collect nectar from nearby flowering plants.
Answer: True

Question 45. Honey is produced by queen bees.
Answer: False

Question 46. Pisciculture is the culture of fish.
Answer: True

Question 47. The cultural fishery is performed in the sea.
Answer: False

Question 48. Brackish water fishery is included under marine fishery.
Answer: False

Question 49. Grass carp is an Indian major carp.
Answer: False

Question 50. Exotic carps are indigenous property.
Answer: False

Question 51. For induced breeding fish are injected with pituitary extract.
Answer: True

Question 52. The pituitary gland of a fish is situated within its head.
Answer: True

Question 53. Tilapia and Koi are sewage-fed fishes.
Answer: True

Question 54. Poultry farming can be done only with ducks and fowl.
Answer: False

Question 55. Table breeds of poultry produce high quantities of meat.
Answer: True

Question 56. Light breeds of fowls weigh between 2 – 3 kg.
Answer: True

Question 57. Electrical batteries remain attached to battery cages.
Answer: False

Question 58. Egg contains a high amount of protein.
Answer: True

Question 59. Broilers are good layers.
Answer: False

 

Chapter 8 Human Food And Food Production Match The Column

 

1.

Column – A Column – B
A. Cereal 1. Peas
B. Pulses 2. Paddy
C. Tuber 3. Black pepper
D. Spice 4. Potato

Answer: A-2,B-1,C-4,D-3

2. 

 Column – A Column – B
A. Vegetable 1. Banana
B. Decorative plant 2. Rose
C. Fruit 3. Tomato
D. Flower 4. Cactus

Answer: A-2,B-1,C-4,D-3

3.

Column – A Column – B
A. Ploughing 1. Swing basket method
B. Sowing 2. Seed drill
C. Irrigation 3. Silo
D. Storage 4. Hoe

Answer: A-4,B-2,C-1,D-3

4.

Column – A Column – B
A. Paddy 1. Camellia
B. Mango 2. Oryza
C. Tea 3. Mangifera

Answer: A-2,B-3,C-1

5.

Column – A Column-B
A. Honeybee 1. Labeo
B. Rohu fish 2. Gall us
C. Fowl 3. Apis

Answer: A-3,B-1,C-2

WBBSE Notes For Class 8 School Science Chapter 8 Human Food And Food Production

Chapter 8 Human Food and Food Production

Introduction

Food is any nutritious substance that people or animals eat or drink or that plants absorb to maintain life and growth.

Food materials consist essentially of protein, carbohydrates, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy. Food manufacturing and processing is one of the world’s largest industries.

Terminologies Associated with Food and Food Production

Agriculture is the process of producing food, feeding products, fiber, and other desired products by the cultivation of certain plants and the raising of domesticated animals (livestock).

The practice of agriculture is also known as ‘farming’. More people in the world are involved in agriculture as their primary economic activity.

Food processing is the transformation of raw ingredients, by physical or chemical means into food, or of food into other forms. Food processing combines raw food ingredients to produce marketable food products that can be easily prepared and served by the consumer.

Food processing typically involves activities such as mincing and macerating, liquefaction, emulsification, cooking (such as boiling, broiling, frying, or grilling),

Pickling and preservation, canning or jarring (primary processing such as dicing or slicing, freezing or drying when leading to secondary products are also included).

Agronomy is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation.

Agronomy encompasses work in the areas of plant genetics, plant physiology, meteorology, and soil science. Agronomy is the application of a combination of Most food and has its origin in plants.

Read And Learn More WBBSE NotesFor Class 8 School Science

Some food is obtained directly from plants, but even animals that are used as food sources are raised by feeding them food derived from plants.

Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Maize, wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.

sciences like biology, chemistry, economics, ecology, earth science, and genetics. Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation.

It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds, and non-food crops such as grass and ornamental trees and plants.

It also includes plant conservation, landscape restoration, landscape and garden design, construction, and maintenance.
A crop is any cultivated plant, fungus, or alga that is harvested for food, clothing, livestock fodder, biofuel, medicine, or other uses.

In contrast, animals that are raised by humans are called livestock, except those that are kept as pets. Crop production is a complex business, requiring many skills (such as biology, agronomy, mechanics, and marketing) and covering a variety of operations throughout the year.

WBBSE Notes For Class 8 School Science Chapter 8 Human Food And Food Production

WBBSE Class 8 Human Food notes

Based on the growing season, the crops grown in India can be classified as Kharif crops and Rabi crops.

Soil management Soil is the basis of farming It delivers water and nutrients to crops, physically supports plants, helps control pests, determines where rainfall goes after it hits the earth, and protects the quality of drinking water, air, and wildlife habitat.

Animal husbandry is the management and care of farm animals by humans for profit, in which genetic qualities and behavior, considered to be advantageous to humans, are further developed.

The term can refer to the practice of selectively breeding and raising livestock to promote desirable traits in animals for utility, sport, pleasure, or research.

Crop

A crop is the annual or seasonal yield of any plant that is grown in significant quantities to be harvested as food, fodder, fuel, or for any other economic purpose. In other words, a crop is the product of a plant grown and harvested on a large scale for subsistence.

Diversity of Crop

Traditional agriculture involved planting a wide diversity of different plants. This had considerable advantages. Among other things, it was a method of insurance.

The farmer who grows a single crop runs the risk that conditions in a particular year might not be appropriate for it. The weather may not be right or his crop might be subject to pest infestations.

This means that the more different crops the farmer grows, the lower must be the risk, since at least some of his crops are likely to tolerate the weather conditions, and the pest outbreak is extremely unlikely to affect each of his crops

Classification of Crop Plants

Importance of classifying the Crop Plants

  1. To get acquainted with crops.
  2. To understand the requirement of soil and water for different crops.
  3. To know the adaptability of crops.
  4. To know the growing habit of crops.
  5. To understand the climatic requirements of different crops.
  6. To know the economic production of the crop plant and its use.
  7. To know the growing season of the crop.
  8. Overall to know the actual conditions required for the cultivation of plants.

1. Classification Based on the growing season

Kharif/Rainy/Monsoon crops: The crops grown in monsoon months from June to Oct-Nov. Require warm, wet weather at major periods of crop growth, also required short day length for flowering, e.g. cotton, rice, jowar, banjara, etc.

Rabi/winter/cold seasons crops: Require winter season to grow well from Oct to March month. Crops grow well in cold and dry weather. Require longer day length for flowering, e.g. wheat, gram, sunflower, etc.

Summer crops: Crops grown in summer months from March to June. Require warm day weather for major growth periods and longer day length for flowering, e.g. groundnuts, watermelon, pumpkins, gourds, etc.

2. Agronomic classification

Grain crops: May be cereals as millets cereals are cultivated grasses grown for their edible starchy grains. The larger grain used as a staple food is cereals, e.g. rice, jowar, wheat, maize, and millets are the small-grained cereals that are of importance as food.

Puise/legume crops: Seeds of leguminous crops plant used as food. On splitting they produce dal which is rich in protein, e.g. green gram, black gram, soybean, pea, cowpea, etc.

Oil seeds crops: Crop seeds are rich in fatty acids, and are used to extract vegetable oil to meet various requirements, e.g. groundnut, mustard, sunflower, linseed, etc.

Forage Crop: It refers to vegetative matter fresh and preserved and utilized as food for animals, e.g. sorghum, elephant grass, etc.

Fiber crops: Grown for fiber yield. Fiber may be obtained from the seed. e.g. cotton, jute, etc.

Roots crops: Roots are the economic production of root crops. e.g. sweet potato, sugar beet, carrot, turnip, etc.

Tuber crop: Crop whose edible portion is not a root but a short thickened underground stem. e.g. potato.

Sugar crops: The two important crops are, sugarcane and sugar beet cultivated for the production of sugar.

Starch crops: Grown for the production of starch, e.g. tapioca, potato, sweet potato, etc.

Drug crop: Used for preparation for medicines, e.g. tobacco, mint, pyrethrum, etc.

Spices and condiments/spices crops: Crop plants as their products are used to flavor taste and sometimes color the fresh preserved food. e.g. ginger, garlic, chili, cumin onion, coriander, cardamom, pepper, turmeric, etc.

Vegetable crops: May be leafy as fruity vegetables, e.g. palak, brinjal, tomato, etc.

Medicinal and aromatic crops: Medicinal plants include cinchona, isabgol, opium poppy, senna, belladonna, rauwolfia, and aromatic plants such as lemon grass, citronella grass, palmarosa, Japanese mint, peppermint, rose, jasmine, henna, etc.

  1. Plantation crops: Tea, coffee, and coconut are important.
  2. Fruit crops: Such as apples, bananas, pears, etc.

3. Classification based on the life of crops/duration of crops

  1. Seasonal crops: A crop completes its life cycle in one season-Karin, Rabi, summer, e.g. rice, jowar, wheat, etc.
  2. Two seasonal crops: Crops complete their life in two seasons, e.g. cotton, turmeric, ginger, etc.
  3. Annual crops: Crops require one full year to complete their life cycle, e.g. sugarcane.
  4. Biennial crops: These grow in one year and flower, fructify and perish the next year. e.g. banana, papaya etc.
  5. Perennial crops: Crops live for several years, e.g. mango, guava, etc.

4. Classification based on cultural method/water

  1. Rain-fed: Crops grow only on rainwater, e.g.
  2. Irrigated crops: Crops grow with the help of Jowar, banjara, mung, etc. of irrigation water, e.g. chili, sugarcane, banana, papaya, etc.

5. Classification based on the economic importance

  1. Cash crop: Grown for earning money, e.g. sugarcane, cotton, etc.
  2. Food crops: Grown for raising food grain for the population and fodder for cattle, e.g.jowar, wheat, rice, etc.

Crop Production and Management

We know that the energy from food is utilized by organisms for carrying out their various bodily functions, such as digestion, respiration, and excretion.

We get our food from plants, animals, or both. Since we all need food, how can we provide food to a large number of people in our country? In order to provide food for a large population— regular production, proper management, and distribution of food are necessary.

Till 10,000 B.C. people were nomadic. They were wandering in groups from place to place in search of food and shelter. They ate raw fruits and vegetables and started hunting for animals for food.

Food production methods for Class 8

Later, they could cultivate the land and produce rice, wheat, and other food crops. Thus, was born ‘Agriculture’. When plants of the same kind are grown and cultivated in one place on a large scale, they are collectively called a crop.

For example, a crop of wheat means that all the plants grown in a field are of wheat. We already know that crops are of different types like cereals, vegetables, and fruits.

These can be classified based on the season in which they grow. India is a vast country. The climatic conditions like temperature, humidity, and rainfall vary from one region to another.

Accordingly, there is a rich variety of crops grown in different parts of the country. Despite this diversity, two broad cropping patterns can be identified. These are:

Kharif Crops: The crops which are sown in the rainy season are called Kharif crops. The rainy season in India is generally from June to September. Paddy, maize, soybean, groundnut, cotton, etc., are Kharif crops.

Rabi Crops: The crops grown in the winter season are called rabi crops. Their period is generally from October to March. Examples of rabi crops are wheat, gram, pea, mustard, and linseed.

Besides these, pulses and vegetables are grown during summer in many places. Basic Practices of Crop Production Cultivation of crops involves several activities undertaken by farmers over a period of time.

 

Kharif Rabi
Season of sowing Rainy season Winter season
Cultivation period June to September October to March
Examples of such crops Paddy, maize and soybeans, pulses, and vegetables are grown during summer Wheat, gram, pea, and mustard

 

You may find that these activities are similar to those carried out by a gardener or even by you when you grow ornamental plants in your house. These activities or tasks are referred to as agricultural practices. These activities are listed below-

  1. Preparation of soil
  2. Sowing
  3. Adding manure and fertilizers
  4. Irrigation
  5. Protection from weeds, pests, etc
  6. Harvesting
  7. Storage.

 

Preparation of soil

The preparation of the soil is the first step before growing a crop. This involves turning the soil and loosening it so that roots can penetrate deep into the soil and also allows the roots to breathe easily.

Loosening of soil helps in the growth of earthworms and microbes which further loosens the soil and also adds humus to it. Need for the soil to be loosened – Soil is rich in minerals, water, air & some living organisms.

The dead plants and animals when decomposed, release nutrients back into the soil making it nutrient-rich. Loosening of soil brings the nutrient, rich soil to the top for the plants to use for their growth.

The process of loosening and turning the soil is called Tilling or Ploughing. Tilling / Ploughing is done by using Ploughs made of wood & iron.

Big pieces of soil or crumbs left in the plowed field are broken with the help of a plank. Leveling of soil is done with the help of a leveler which is important for the purpose of Sowing and Irrigation.

Tilling also ensures proper mixing of manure with soil. A home is also sometimes used for removing weeds and for plowing.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Preparation of soil

Understanding food sources for Class 8

Agricultural Implements: Before sowing the seeds, it is necessary to break the soil to the size of grains to get a better yield. This is done with the help of various tools. The main tools used for this purpose are the plow, hoe, and cultivator.

Plough: This is being used since ancient times for tilling the soil, adding fertilizers to the crop, removing the weeds, scraping of soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Plough

 

Removing the weeds, scraping off the soil, etc. This implement is made of wood and is drawn by a pair of bulls or other animals (horses, camels, etc.).

It contains a strong triangular iron strip called plowshare. The main part of the plow is a long log of wood which is called a plow shaft.

There is a handle at one end of the shaft. The other end is attached to a beam that is placed on the bulls’ necks. One pair of bulls and a man can easily operate the plow.

The indigenous wooden plow is increasingly being replaced by iron plows nowadays.

Hoe: It is a simple tool that is used for removing weeds and for loosening the soil. It has a long rod of wood or iron. A strong, broad, and bent plate of iron is fixed to one of its ends and works like a blade. It is pulled by animals.

Cultivator: Nowadays plowing is done by tractor-driven cultivators. The use of cultivators saves labor and time. For plowing small agricultural land or flower garden nowadays power tiller is used.

Sowing

Sowing is the most important part of crop production as it decides the final yield. Good quality seeds that are clear and healthy are selected by the farmers to get a high yield.

Good seeds can be separated from damaged ones by putting them into water. Damaged seeds are hollow and float on the water while good quality, healthy seeds settle at the bottom.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production taditional tool seed drill

 

There are two types of sowing tools.

1. Traditional Tool is a funnel-shaped tool that is filled with seeds, while sowing, seeds are passed down through pipes having sharp ends. The ends are sharp as they pierce into the soil and put the seeds there.

2. Seed Drill is the modern-day tool for sowing seeds & is used with the help of tractors. This tool has an edge over the traditional tool as it sows the seeds uniformly at proper distances & depths.

It also covers the seeds with soil after sowing which prevents damage caused by birds. Seed Drill saves time and labor. An appropriate distance between the seeds is important to avoid overcrowding of plants.

This allows plants to get sufficient sunlight, a few plants have to be removed to prevent nutrients and water from the soil. Sometimes overcrowding.

Adding manure and fertilizers

The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilizers.

Soil supplies mineral nutrients to the crop. These nutrients are essential for the growth of plants. Continuous growing of crops makes the soil poorer in certain nutrients.

Therefore, farmers have to add manure to the fields to replenish the soil with nutrients. This process is called manuring. Improper or insufficient manuring results in weak plants.

Manure is an organic substance obtained from the decomposition of plant or animal wastes. Farmers dump plant and animal waste in pits in open places and allow it to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.

WBBSE Chapter 8 summary on food production

Fertilizers are chemical substances that are rich in a particular nutrient. How are these different from manure? Fertilizers are produced in factories.

Some examples of fertilizers are- urea, ammonium sulfate, superphosphate, potash, and NPK (Nitrogen, Phosphorus, and Potassium). The use of fertilizers has helped farmers to get a better yield of crops such as wheat, paddy, and maize.

But excessive use of fertilizers has made the soil less fertile. Fertilizers have also become a source of water pollution. Therefore, in order to maintain the fertility of the soil,

we have to substitute fertilizers with organic manure or leave the field uncultivated (fallow) in between two crops.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Adding manure and fertilisers

 

The use of manure improves soil texture as well as its water-retaining capacity. It replenishes the soil with all the nutrients.

Another method of replenishing the soil with nutrients is through crop rotation. This can be done by growing different crops alternately.

Farmers sometimes grow legumes as fodder in one season and wheat in the next season. This helps in the replenishment of the soil with nitrogen.

In the previous chapter, you learned about Rhizobium bacteria. These are present in the nodules of the roots of leguminous plants. They fix atmospheric nitrogen.

Differences between Fertiliser and Manure

 

Fertiliser Manure
(1) A fertilizer is an inorganic salt. (1) Manure is a natural substance obtained by the decomposition of cattle dung, human waste, and plant residues.
(2) A fertilizer is prepared in factories. (2) Manure can be prepared in the fields.
(3) A fertilizer does not provide any humus to the soil. (3) Manure provides a lot of humus to the soil.
(4) Fertilisers are very rich in plant nutrients like nitrogen, phosphorus, and potassium. (4) Manure is relatively less rich in plant nutrients.

 

Advantages of Manure: Organic manure is considered better than fertilizers. This is because It enhances the water-holding capacity of the soil. It makes the soil porous which exchange of gases becomes easy.

Irrigation

All living beings need water to live. Water is important for the proper growth and development of flowers, fruits, and seeds of plants. Water is absorbed by the plant roots.

Along with water, minerals, and fertilizers are also absorbed. Plants contain nearly 90% water. Water is essential because the germination of seeds does not take place under dry conditions.

Nutrients dissolved in the water get transported to each part of the plant. Water also protects the crop from both frost and hot air currents. To maintain the moisture of the soil for healthy crop growth, fields have to be watered regularly.

The supply of water to crops at different intervals is called irrigation. The time and frequency of irrigation vary from crop to crop, soil to soil, and season to season.

In summer, the frequency of watering is higher due to the increased rate of evaporation of water from the soil and the leaves.

Sources of irrigation: The sources of irrigation are— wells, tube wells, ponds, lakes, rivers, dams, and canals.

Traditional Methods of Irrigation

The water available in wells, lakes, and canals is lifted up by different methods in different regions, for taking it to the fields.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Taditional methods o0f irrigation

Protection from Weeds

In a field, many other undesirable plants may be Cattle or human labor is used in these methods. So these methods are cheaper but less efficient. The various traditional ways are:

  1. Moat (pulley system)
  2. Chain pump
  3. Dhekli, and
  4. Rahat (Lever system)

Pumps are commonly used for lifting water. Diesel, biogas, electricity, and solar energy are used to run these pumps.
Modern Methods of Irrigation Modern methods of irrigation help us to use water economically. The main methods used are as follows:

Sprinkler System: This system is more useful on uneven land where sufficient water is not available. The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals.

When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. The sprinkler is very useful for sandy soil.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production drip system

 

Drip system: In this system, the water falls drop by drop just at the position of the roots. So it is called a drip system. It is the best technique for watering fruit plants, gardens, and trees.

The system provides water to plants drop by drop. Water is not wasted at all. It is a boon in regions where the availability of water is poor and grows naturally along with the crop. These undesirable plants are called weeds.

The removal of weeds is called weeding. Weeding is necessary since weeds compete with crop plants for water, nutrients, space, and light.

Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings.

Farmers adopt many ways to remove weeds and control their growth. Tilling before sowing crops helps in uprooting and killing weeds, which may then dry up and get mixed with the soil.

Protection from weeds 

The best time for the removal of weeds is before they produce flowers and seeds. Manual removal includes the physical removal of weeds by uprooting or cutting them close to the ground, from time to time.

This is done with the help of a kauri. A seed drill is also used to uproot weeds repel, or control certain forms of plants Weeds are also controlled by using certain chemicals, called weedicides, like 2,4-D, Dalapon, Pichloram, etc.

These are sprayed in the fields to kill the weeds. They do not damage crops. The weedicides are diluted with water to the extent required and sprayed in the fields with a sprayer animal life that is considered to be pests.

Pesticides include herbicides for destroying weeds and other unwanted vegetation, insecticides for controlling a wide variety of insects,

Fungicides are used to prevent the growth of molds and mildew, disinfectants for preventing the spread of bacteria, and rodenticide compounds are used to control mice and rats.

Protection from pests

A pest is a plant or animal detrimental to humans or human concerns (such as agriculture or ‘ livestock production). Pest control refers to the regulation or management of a species defined as a pest, usually

Because it is perceived to be detrimental to a person’s health, ecology, or economy. Pest control is at least as old as agriculture, as there has always been a need to keep crops free from pests,

Types of pest control: Several methods of pest control are adapted-Biological pest control is the control of one through the control and management of natural predators and parasites.

Mechanical pest control is the use of hands-on techniques as well as simple equipment, devices, and natural ingredients that provide a protective barrier between plants and insects.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production weedicides

Types of crops and their uses Class 8

Physical pest control is a method of getting rid of insects and small rodents by removing, attacking, and setting up barriers that will prevent further destruction of one’s plants, or forcing insect infestations to become visual.

Every pest control chemical has a different mode of action. The mode of action is the way that the insecticide kills or repels the target pest. Most chemicals used in pest control are poisonous to humans.

A pesticide is any substance used to kill, Pesticide application refers to the practical way in which pesticides are delivered to their biological targets (e.g.pest organism, crop, or another plant).

One of the more common forms of pesticide application, especially in conventional agriculture, is the use of mechanical sprayers. Hydraulic sprayers consist of a tank, a pump, a lance (for single nozzles) or boom, and a nozzle (or multiple nozzles)

Harvesting

Harvesting a crop is an important task. The cutting of a crop after it is mature is called harvesting. In harvesting, crops are pulled out or cut close to the ground.

It usually takes 3 to 4 months for a cereal crop to mature. Harvesting in our country is either done manually by sickle or by a machine called a harvester.

In the harvested crop, the grain seeds need to be separated from the chaff. This process is called threshing. This is carried out with the help of a machine called ‘combine’ which is in fact a combined harvester and thresher.

After harvesting, sometimes stubs are left in the field, which is burnt by farmers. It causes air pollution. It may also catch fire and damage the crops lying in the fields. Farmers with small holdings of land do the separation of grain and chaff by winnowing.

Harvest Festivals: After three or four months of hard work there comes the day of the harvest. The sight of golden fields of standing crops, laden with grain, fills the hearts of farmers with joy and a sense of well-being.

The efforts of the past season have borne fruit and it is time to relax and enjoy a little. The period of harvest is, thus, of great joy and happiness in all parts of India.

Men and women celebrate it with great enthusiasm. Special festivals associated with the harvest season are Pongal, Baisakhi, Holi, Diwali, Nabanya, and Bihu.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production sickle

Storage

Storage of crops is an important task. If the crop grains are to be kept for a longer time, they should be safe from moisture, insects, rats, and microorganisms.

The fresh crop has more moisture. If freshly harvested grains (seeds) are stored without drying, they may get spoilt or attacked by organisms, losing their germination capacity.

Hence, before storing them, the grains are properly dried in the sun to reduce their moisture in them. This prevents attack by insect pests, bacteria, and fungi. Farmers store grains in jute bags or metallic bins.

However, large-scale storage of grains is done in silos and granaries to protect them from pests like rats and insects. Dried neem leaves are used for storing food grains at home.

For storing large quantities of grains in big godowns, specific chemical treatments are required to protect them from pests and microorganisms.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production storage.2

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing Storage

Food Production Processes

Examples of a few food production processes are given below-

Paddy/Rice

Rice is our principal food. Nearly half of the people of the world live on rice. We get it from paddy. The farmer first tills land very well.

Then they sow the seeds. In a few days, the seeds come up. About two months after, ears of paddy come out. After three months more, the paddy ripens.

Then we husk paddy and get rice. Rice is found all over the world. It grows best in India, Bangladesh, Pakistan, Burma, China, Japan, Thailand, etc.

Rice is a kind of food grain. It is obtained from a plant called paddy. It is a one-time breeding plant. It grows from two to three feet high. It feeds millions of people in the world.

Rice grows well in hot and moist climates. Sufficient rainfall is required for the proper growth of rice. Bangladesh, India, Pakistan, China, Japan, and Thailand are the main rice-producing countries in Asia.

Kinds of rice: There are four kinds of rice in our country. They are: push, aman, boro, and IRRI. Aush is sown in the month of baishakh and reaped in caravan or Bhadra.

Aman is sown in asar or sravan and reaped in agrarian or push. Boro is sown in winter and reaped in spring. IRRI is cultivated all year round.

Method of cultivation: Farmers plow and harrow their lands again and again and prepare them well for sowing seeds. Weeding is required for the proper growth of the plants.

Paddy becomes ripe in four to five months. Then they are cut, tied into bundles, carried home, and thrashed. Next, they are boiled, dried, and husked. This is how rice is obtained.

Utility: Rice is our staple food. We get many kinds of food from rice. We make chira, muri, khai, cake, polar, biriani, etc. from rice. Straw and husk are used as fuel. They are also used as fodder for cattle.

Process of cultivation

Rice cultivation is a complex activity that requires a series of processes to achieve the finished product. In general, paddy cultivation is quite distinctive and observes the following steps:

1. Preparation of Field

Paddy farmers get their fields ready before the rainy season. The weeds are cleared and the field is plowed by buffaloes or tractors to a depth of few Manures and fertilizers are added to the soil.

The whole surface is then covered with water of about 2.5 cm depth. The field then becomes ready for receiving seedlings from the nursery.

2. Transplantation

Generally, paddy seedlings are first prepared in the nursery and then transplanting is done in the field after about 40 days. Although in some areas of India and Sri Lanka seeds have been sown directly in the field and the seedlings sprout when the rain comes,

The yield of paddy from transplanting is greater than the direct sowing. The transplanted paddy also grows faster because of regular spacing and matures within a shorter period.

3. Field Maintenance and Irrigation

Paddy fields also require regular maintenance, such as occasional weeding and thinning out the more crowded patches, level of water is to be maintained according to the growth, and the fields are drained dry before the crop is harvested. Water standing 3 to 5 cm is essential at the base of the plant for proper growth.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production feild maintaince and irragation

4. Harvesting

The traditional harvesting system is either through a curved knife or a sharp-edged knife. It is very labor-intensive. Harvesting is done in the dry season when the weather is sunny. Mechanical combines which cut and thresh are used in Japan.

5. Threshing, Winnowing, and Milling

After the paddy stalks have been gathered and dried for a brief spell, their threshing is usually done. By beating the sheaves against the bars, the grains are separated from the stalks.

Now threshing machines have also been developed. Winnowing is a process of removing unwanted particles from paddy grains. The grains fall to the mat while lighter chaff blows out. Sometimes hand winnowing machines are also used.

Milling means the removal of the yellowish husks from paddy so that white or polished rice is obtained. In a rice mill, the paddy is made to pass between varying sets of hullers or rollers till it is milled or polished.

Mango

Mango (Mangifera indica) belonging to Family Anacardiaceae is the most important commercially grown fruit crop in the country. Mango is the leading fruit crop of India and is considered to be the king of fruits.

Besides the delicious taste, excellent flavor, and attractive fragrance, it is rich in vitamins A and C. The tree is hardy in nature and requires comparatively low maintenance costs.

Mango occupies 22% of the total under fruits comprising 1.2 million hectares, with a total production of 11 million tones. b

Uttar Pradesh and Andhra Pradesh are having the largest area under mango each with around 25% of the total area followed by Bihar, Karnataka, Kerala, and Tamil Nadu.

Mango fruit is utilized at all stages of its development both in its immature and mature state. Raw fruits are used for making chutney, pickles, and juices.

The ripe fruits besides being used for dessert are also utilized for preparing several products like squashes, syrups, nectars, jams, and jellies.

India is the largest mango-producing country, accounting for about 60% of world production, the export of fresh fruit is Limited to Alphonso and Dashehari varieties.

India’s share in the world mango market is about 15 percent. Mango accounts for 40 percent of the total fruit exports from the country. There is good scope for increasing the area and productivity of mango in the country.

 

Importance of food production for Class 8

Climate: Mango can be grown under both tropical and sub-tropical climates from sea level to 1400 m altitude, provided there is no high humidity, rain, or frost during the flowering period.

Places with good rainfall and dry summer are ideal for mango cultivation. It is better to avoid areas with winds and cyclones which may cause flower and fruit shedding and breaking of branches.

Soil: Mango comes up on a wide range of soils from alluvial to laterite provided they are deep (minimum 6′) and well drained. It prefers slightly acidic soils.

Varieties: Though there are nearly 1000 varieties of mango in India, only the following varieties are grown in different states: Alphonso,

the simplest way is by pouring the paddy down from a height on a windy day to a large square mat on open Bangalore, Banganpalli, Bombai, Bombay Green, Dashehari, Fazli, Fernandin, Himsagar, Kesar, KishenBhog, Langra, Mankhurd, Mulgoa, Neelam, Samarbehist, Chausa, Suvarnarekha, Vanaraj and Zardalu.

Recently some mango hybrids have been released for cultivation by different institutes/ universities. These are – mallika, amrapali, mangeera, ratna, arkaanmol, etc.

Propagation: Farmers should always get vegetatively propagated, true-to-type plants from recognized nurseries. Inarching, veneer grafting, side grafting, and epicotyl grafting are the popular methods of propagation in mango.

Planting: Land should be prepared by deep plowing followed by harrowing and leveling with a gentle slope for good drainage.
Planting is usually done in the month of July- August in rainfed areas and during February- March in irrigated areas. In case of heavy rainfall zones, planting is taken up at the end of the rainy season.

One-year-old healthy, straight-growing grafts from reliable sources can be planted at the center of pits along with the ball of the earth intact during the rainy season in such a way that the roots are not expanded and the graft union is above the ground level. Plants should be irrigated immediately after planting.

Fertiliser Application: Fertilizers may be applied in two split doses, one half immediately after the harvesting of fruits in June/July and the other half in October, in both young and old orchards followed by irrigation if there are no rains. Foliar application of 3% urea in sandy soils is recommended before flowering.

Tea

Tea is the dried leaf of a bush. It contains theine and when added to boiling water along with sugar and milk, it gives a very cheap and stimulating drink.

Thus it is the most important beverage crop in India. Tea bush is supposed to be indigenous to China but it was reported by Major Robert Bruce in 1823 that indigenous tea bushes grew wild on the hill slopes of upper Assam. In the year 1840, tea seeds were.

Irrigation: Young plants are watered frequently for proper establishment. In the case of grown-up trees, irrigation at 10 to 15 days intervals from fruit set to maturity is beneficial for improving yield.

Harvesting and yield: The yield of mango varies greatly, depending upon the variety and agro-climatic conditions prevailing in a region. Grafted mango trees start bearing from the fifth year onward. However, seedling trees may take 8-10 years.

Economic Importance: Raw fruits of local varieties of mango trees are used for preparing various traditional products like raw slices in brine, amchur, pickle, murabba, chutney, pane (sharbat), etc.

Presently, the raw fruit of local varieties of mango is used for preparing pickles and raw slices in brine on the commercial scale while fruits of the Alphonso variety are used for squash in the coastal western zone.

The wood is used as timber, and dried twigs are used for religious purposes. The mango kernel also contains about 8-10% good-quality fat which can be used for saponification. Its starch is used in the confectionery industry.

Weed control and Plant protection: The mango orchard should be completely free from weeds. In order to control weeds, shallow hoeing at quarterly intervals should be done. Black plastic mulch should be used to restrict the germination of weed seeds and suppression of weed growth.

Mango crop suffers seriously from pests: hopper, mealy bug, fruit fly, shoot and stem borer, and stone weevil. The Hoppers are most divesting during the flowering period as they suck the sap from tender shoots, leaves, and panicles.

Proper pesticides are recommended for the protection of trees imported from China and commercial tea plantations were set up in the Brahmaputra valley.

There are four main types of tea: green tea, black tea, oolong tea, and white tea. There are even more varieties, including flavored, scented, and “herbal infusions,” but for the sake of simplicity, we’ll focus on the big four right now.

What many people don’t know is that these four types of tea come from one plant, not four different species of plant.

All tea begins with the plant known as Camellia sinensis, it’s the way the tea leaves are processed that gives us the different teas and their specific taste, color, and scent.

Conditions of Growth

Tea bush is a tropical and sub-tropical plant and thrives well in a hot and humid climate. There is a very close relationship between climate, yield, and quality of tea. The ideal temperature for its growth is 208-30°C and temperatures above 35°C and below 10°C are harmful to the bush.

It requires 150-300 cm of annual rainfall which should be well distributed throughout the year. While the prolonged dry spell is harmful to tea, high humidity, and heavy demand morning fog favor the rapid development of young leaves.

Alternate waves of warm and cool winds are very helpful for tea leaves. Tea is a shade-loving plant and develops more vigorously when planted along with shady trees.

In order to increase the yield, the proper dose of nitrogenous fertilizers such; as ammonium sulfate should be given to the soil.
Although tea requires heavy rainfall for its growth, stagnant water is injurious to its roots.

It is, therefore, grown on hill slopes where water drains away easily and water-logging does not take place. However, it grows equally well in the valley if the drainage is good. Most of the tea plantations in India are found at elevations varying from 600 to 1,800 meters above sea level.

Tea is a labor-intensive crop and requires an abundant supply of cheap and skilled labor, especially at the time of plucking the tea leaves.

This is a tedious process that requires skilled manipulation of fingers for plucking two leaves and a bud at a time. For this purpose, women laborers are employed in large numbers.

Distribution

Tea cultivation in India is highly concentrated in a few selected pockets. The following three areas of tea cultivation are identified according to their importance as tea producers and their location.

North-Eastern India: It is more or less a triangular area mainly in Assam and West Bengal. Assam is the largest producer of tea accounting for over 51 percent of the production and over 53 percent of the area under tea cultivation in India.

West Bengal is the second largest producer contributing over 22 percent of India’s tea from about one-fourth of the country’s total area under tea cultivation.

The entire tea of West Bengal is produced in three northern districts of Darjeeling, Jalpaiguri, and Coochbehar.
South India: In South India tea is produced in Nilgiri, Cardamom, Palni, and Anaimalai hills in Tamil Nadu, Kerala, and Karnataka states.

Northwest India: Some of the tea is produced in the Dehra Dun, Almora, and Garhwal districts of Uttaranchal and in Kangra Valley and Mandi district of Himachal Pradesh. Green tea is produced in the Kangra valley of Himachal Pradesh.

Plantations

Planting: Planting is a crucial operation as it basically determines the development and productive level of tea throughout its economic life.

Wrong planting of good planting materials is doubly unproductive as an investment is lost both on account of producing the plants and in the failure to put them up for productivity. Therefore, care, planning, and refinement of techniques are essential for long-term benefits.

Pruning: It basically helps in maintaining the plant as a low bush in a phase of continuous vegetative growth. Pruning both stimulates and controls growth.

It removes dead, diseased, and overage wood, and thus helps rejuvenate bushes that have crossed the period of maximum productivity.

Fertilizer: The nutrients that are removed from the plant as yield and from the soil by the plant for its growth, should be replenished.

ideally, nutrient requirements should be related to local soil conditions in addition to yield and they must be monitored continuously to ensure an optimum balance of nutrients.

Weed control: Weeds affect tea by competing with it for moisture, nutrients, and sunlight. The ultimate effect is a considerable reduction in yield.

Thus, the timing of weed emergence relative to the growth stages of tea is an important parameter in weed management. Apart from directly causing crop losses, weeds in tea areas also act as secondary hosts for some important pests of tea.

Pest Management: The simultaneous presence of different species of mites and insects, each with their characteristic mode of feeding, diverse habitat, and seasonal cycles, call for optimal management of the pests which should be both ecologically and economically sound.

Crop duration and harvest: Plucking commences when the tea bush is 3 years old. The plucking of the extreme tip of the growing branch consists of an unopened bud together with two leaves popularly known as “Two leaves and a bud”, while fine plucking is anything less than this.

In South India, plucking continues throughout the year at weekly intervals during March-May and at intervals of 10 -14 days during the other months.

Processing of tea

Once workers gather enough quantities of tea leaves, their stash is quickly carried over to a tea factory located right on the plantation.

The factory is placed close to the source of the leaves because once the tea is plucked, oxidation immediately begins. The oxidation process is important in understanding tea — it must be closely monitored during production and is essential in determining the type and quality of the tea.

Oxidation is what happens when you cut up a piece of fruit and leave it out for too long — the color of the fruit changes, usually turning brown or black. Depending on the type of tea you want, oxidation can be a necessary part of processing tea leaves.

Tea tasting is the process in which a trained taster determines the quality of a particular tea. Due to climatic conditions, topography, manufacturing process, and different clones of the Camellia sinensis plant (tea), the final product may have vastly different flavors and appearances.

These differences can be tasted by a trained taster in order to ascertain the quality prior to the sale of possibly blended tea.

Animal Husbandry

Food is obtained from animals for which animals are reared & are provided with proper food & shelter. This is called Animal Husbandry. Examples of food obtained from animals are- eggs, milk, meat, etc.

  1. Honeybee and apiculture
  2. Apiculture is the management and study of honeybees.

Although apiculture refers to the honeybee, the vital role all bees play in the pollination of crops and flowering plants has caused apiculture to also include the management and study of non-Apis bees such as bumblebees and leafcutter bees.

Bees collect pollen and nectar. Pollen is the protein source needed for bee brood development while nectar is the carbohydrate source providing energy.

(Ni) Nectar is a sugar solution produced by flowers containing about 80% water and 20% sugar.

Foraging bees store the nectar in the ‘honey sac’ where the enzyme invertase will change complex sugars into simple sugars called monosaccharides.

Upon return to the hive, the foraging bee will disgorge the partially converted nectar solution and offer it to other bees. Housekeeping bees will complete the enzymatic conversion, further removing water until the honey solution contains between 14 – 20% water.

Honey is too dry for any microbes to live in. Honey is non-perishable and can be kept indefinitely in a cool, dry place.

The flavor, aroma, and color of honey are determined by the floral source The honeybee colony is comprised of one queen, thousands of worker bees and a few hundred male bees called drones. Colony size varies according to the season and condition of the colony.

Activities in the honeybee colony

A colony of honeybees comprises a cluster of several to 60,000 workers (sexually immature females), a queen (a sexually developed female), and, depending on the colony population and season of the year, a few to several hundred drones (sexually developed males). A colony normally has only one queen, whose sole function is egg-laying.

The bees cluster loosely over several wax combs, the cells of which are used to store honey (carbohydrate food) and pollen (protein food) and to rear young bees to replace old adults.

A beehive is an enclosed structure in which honey bees live and raise their young. Although worker bees only live for approximately six weeks, they spend their lives performing tasks that benefit the survival of their colony.

When a worker bee turns 10 days old, it develops a wax-producing gland inside its abdomen. Workers gather nectar from different flowering plants and carry nectar within their honey sacs, where it mixes with a specialized enzyme.

After returning to the hive, the worker bee vomits the nectar in the honey chamber and moves its wings very rapidly. By the flowing air, the liquid from the nectar evaporates and the stuff becomes honey.

The glands of worker bees convert the sugar contents of honey into wax, which oozes through the bee’s small pores to produce tiny flakes of wax on their abdomens.

Workers chew these pieces of wax until they become soft and moldable, and then add the chewed wax to the honeycomb construction.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production honey bee colony

 

Bee Development

All three types of adult honey bees pass through three developmental stages before emerging as adults: egg, larva, and pupa. The three stages are collectively labeled brood.

While the developmental stages are similar, they do differ in duration. Unfertilized eggs become drones, while fertilized eggs become either workers or queens.

Nutrition plays an important part in the caste development of female bees; larvae destined to become workers receive less royal jelly and more of a mixture of honey and pollen compared to the copious amounts of royal jelly that the queen larva receives.

Types of honeybees

  1. Four important species of honeybees are as follows.
  2. The rock bee, Apis dorsata.
  3. The Indian hive bee, Apis cerana indica. The Indian species in not Apis indica; it is Apis cerana indice.
  4. The little bee, Apisflorea.
  5. The European or Italian bee, Apis mellifera.
  6. Castes of Honeybee

Honeybee is a social insect. The nest of the honeybee is known as a beehive. A hive in summer consists of 32 to 50 thousand individuals, depending on the locality.

The members of honeybees are of three castes namely the queen bee, the worker bee, and the drone bee. All three types depend on each other for their existence. There is normally one queen, 10,000 to 30,000 workers, and a few hundred drones in a colony.

Queen Bee: There is only one queen in a honeybee colony. Queens are fertile females formed from fertilized eggs. It is slightly larger than a worker bee, with a longer abdomen.

It does not have pollen baskets on her legs. Eggs destined to become queens are laid in a larger cell, and the larvae are fed only royal jelly.

The royal jelly is a salivary secretion of the worker bees. The adult queen’s sole duty is to lay eggs, up to 2,000
a day.

it is fed by the workers and never leaves the hive except to mate. Queen bees also have stings and use them in battles with each other for dominance of the colony.

The life span of a queen bee is 3-4 years. When the colony is crowded with adult bees, the queen leaves with a set of workers to establish new colonies and promote propagation. This natural phenomenon is called swarming.

Drone Bee: Drones are haploid fertile males because they develop parthenogenetically from unfertilized eggs. They are larger than workers and smaller than queens.

They are quite noisy and unable to gather food. They are stingless and their sole biological function is to mate with the queen. The number of drones in a colony varies from 200-300 but during unfavorable seasons they are driven out.

Worker Bee: The vast majority of adult honey bees in any colony are female worker bees. The worker bees are sterile females. They have no individual existence throughout their life. They labor for the betterment of the colony.

The functions of the worker bees are: tending and feeding young bees (larvae), making honey, making royal jelly and beebread to feed larvae, producing wax, cooling the hive by fanning wings, gathering and storing pollen, nectar, and water, guarding the hive, building, cleaning and repairing the comb, and feeding and taking care of the queen and drones.

Life cycle: The virgin queen bee mates once in her life. During the breeding season of winter, a unique flight takes place by one queen followed by several drones.

This flight is called the “nuptial flight”. After mating, she returns to the hive and lays eggs. Honeybees pass through four distinct life stages namely the egg, larva, pupa, and adult through metamorphosis.

The queen bee lays an egg in the comb. The egg generally hatches into a larva which is a legless grub that resembles a tiny white sausage.

The larva is fed with a mixture of pollen and nectar called beebread. However, the queen-forming larvae are fed on royal jelly for full larval life and they are taken for further development into a special chamber called the queen’s chamber.

The cell is capped with wax by worker bees. Inside the cell larva spins a delicate silken cocoon around itself and the larva transforms into a pupa. The pupa doesn’t eat.

Ultimately the adult comes out of the cocoon. The queen, worker, and drone bees take 16,21, and 24 days respectively for their complete development.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production Mordern beehive structure

 

How Do Honeybees Make Hives?

Worker honeybees make hives to store honey and feed themselves throughout winter when they cannot go outdoors to forage for food.

Honey bee hives are made of six-sided tubes, which are the shapes for optimal honey production because they require less wax and can hold more honey.

Similar to the habits of domesticated honeybees, they construct hives by chewing wax until it becomes soft, then bonding large quantities of wax into the cells of a honeycomb.

Structure of a bee comb. The combs of bees are formed mainly by the secretion from the wax glands present in the abdomen of the worker bee The cells of the comb are of various types.

The storage cells’ contain honey and pollen. They are. built in the margin and at the top of the comb. The brood cells contain the young stages of the honeybees and they are built in the center and the lower part of the comb.

Young ones of honey bees are collectively called broods. Brood chamber is divided into three types they are, Worker-chamber, Drone-chamber, Queen -chamber There is no special chamber for adults except the queen. They move on the surface of the comb.

Modern beehive structure: The modern beehive is a movable-frame hive. It is a wooden frame box made of single or double walls. A modern hive consists of a bottom board, brood chamber, supper chamber, inner cover, and top cover.

They are placed one above the other and fixed on a stand. The bottom board acts as the entrance for the bees. The brood chamber is a wooden box inside which numerous frames called “comb foundations” are fixed.

Comb foundations consist of sheets of pure bee wax. These wax sheets are embossed with the pattern of hexagons of a size equal to the base of natural brood cells.

The worker bees secrete wax to extend the walls of these cells. The comb foundation helps in controlling the rise of the cells and reduces the number of drone cells.

These frames of the comb are movable and can be lifted, hence the name for the hive “movable frame hive”. The chamber above the brood chamber is the super chamber inside which honey is secreted and stored.

This equipment has narrow spaces of 4 mm which allows only the workers to enter the super chamber. The top cover can be lifted to inspect the state of the colony or honey formation.

In India, apart from the modern hive, another three types of beehive namely Langstroth, Newton, and Jeolikote are in practice.
tablespoon of sugar will give you about 15 calories.

Furthermore, the carbohydrates in honey can be easily converted into glucose by even the most sensitive stomachs, since it is very easy for the body to digest this pure, natural substance.

Source of Vitamins and Minerals: Honey contains a variety of vitamins and minerals. The type of vitamins and minerals and their quantity depend on the type of flowers used for apiculture. Commonly, honey contains Vitamin C, Calcium, and Iron.

Antibacterial and Antifungal Properties: Honey has antibacterial and antifungal properties, so it is often used as a natural antiseptic in traditional medicines.

Antioxidants: Honey contains nutraceuticals, which are very effective for the removal of free radicals from the body. As a result, our body’s immunity is improved against many conditions, even potentially fatal ones like cancer or heart disease.

Beehive products

Honey: Honey has been treasured as one of nature’s most perfect food. Other than honey, the products such as bee wax, bee venom, propolis, royal jelly, and pollen are obtained as beehive products.

Health Benefits of Honey: The health benefits of honey include the following treatments, taken from both traditional and modern medical experts. aquatic (freshwater and marine) organisms like fish, prawns, crabs, pearls, etc.

Pisciculture- This is the method of fish farming in which fish are raised in an artificial way for breeding and transportation.

Aquaculture- Aquaculture though simply means fish farming, in a broader sense, it is farming of aquatic organisms like fish, prawns, etc., and plants for breeding and rearing.

Fish Culture or Pisciculture

Fish is one of the most delicious and widely eaten aquatic animals and it is enriched with omega-3- fatty acid, a necessary constituent of a balanced diet.

As fish is a beloved food item all over the world, so its cultivation and harvesting are done on a larger scale in different parts of the globe.

Some branches of cultivation and harvesting fish are known as Fisheries, Pisciculture, Aquaculture, and Mariculture. Let us see the difference between these different ways of producing fish a larger scale.

Terminology

Fisheries- It deals with all the aspects of harvesting or raising economically important

Weight Loss: Though honey has more calories than sugar, when honey is consumed with warm water, it helps in digesting the fat stored in your body. Similarly, honey and lemon juice as well as honey and cinnamon help in reducing weight.

Energy Source: Honey contains about 64 calories per tablespoon. Therefore, honey is used by many people as a source of energy. On the other hand, aquatic (freshwater and marine) organisms like fish, prawns, crabs, pearls, etc.

Pisciculture- This is the method of fish farming in which fishes are raised in artificial way for breeding and transportation.

Aquaculture- Aquaculture though simply means fish farming, in a broader sense, it is farming of aquatic organisms like fish, prawns, etc., and plants for breeding and rearing.

Mariculture- Mariculture involves the cultivation of only marine organisms, unlike any aquatic organism. This is the method of fish farming which is done usually on a very broader scale means by forming an enclosed section of the ocean.

Type of fisheries

Depending on the type of resources, it may be of the following types-
Capture fisheries: The process of obtaining fish from natural resources like lakes, rivers, ponds, etc. is called capture fishing. Capture fisheries are the exploitation of aquatic organisms without stocking the seed.

Recruitment of the species occurs naturally. This is carried out in the sea, rivers, reservoirs, etc. Fish yield decreases gradually in capture fisheries due to indiscriminate catching of fish including brooders and juveniles.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing type of fisheers

 

Culture fisheries: It is the production of fish in a given body of water such as ponds, lakes, or reservoirs using scientific methods of feeding, breeding, etc.

so as to enhance the output is called culture fishing-A culture fishery is the cultivation of selected fishes in confined areas with utmost care to get maximum yield.

The seed is stocked, nursed, and reared in confined waters, and then the crop is harvested. Culture takes place in ponds, which are fertilized, and supplementary feeds are provided to fish to get maximum yield.

In order to overcome the problems found in capture fisheries to increase production, considerable attention is being given to the culture fisheries.

Fishing in India: Fishing in India is a major industry in its coastal states, employing over 14 million people. Fish production in India has increased more than tenfold since its independence in 1947.

According to the Food and Agriculture Organization (FAO) of the United Nations, fish output in India doubled between 1990 and 2010.

India is endowed with vast and varied aquatic resources (Marine and Inland) amenable for capture fisheries. India is the third-largest producer of fish and the second-largest producer of inland fish in the world.

The fisheries sector provides employment to over 11 million people engaged fully, partially, or in subsidiary activities pertaining to the sector, with an equally impressive segment of the population engaged in ancillary activities.

The potential of fish production from marine and inland sources has been estimated at 3.9 million tonnes and 4.5 million tonnes, respectively.

Inland Fisheries: Inland waters are aquatic-influenced environments located within land boundaries. This includes those located in coastal areas, even where adjacent to marine environments.

Inland water systems can be fresh, saline, or a mix of the two (brackish water). Inland resources comprise of rivers and canals, estuaries, floodplains, wetlands, lagoons, and reservoirs.

While the marine water bodies are used mainly for capturing fisheries resources, the inland water bodies are widely used both for culture and capture fisheries.

Inland capture fisheries of India have an important place; it contributes to about 30% of the total fish production.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing marine fisheers

 

Marine Fisheries: The captured marine fishery resource of India comprises a long coastline (8118 km.) and an Exclusive Economic Zone (EEZ) (2.025 sq. km).

Marine capture fisheries play a vital role in India’s economy, providing employment and income to nearly two million people. Out of the total fish production in India, about 70% is obtained from the sea.

This gives the idea that how important is the marine fishery with its great economic and commercial values.

There are two main coastlines in India i.e., the East coast and the West coast. Out of these two the west coast is more productive because of better circulation and more oceanic character of its water.

Several exploratory surveys of fish wealth in the deep water on both coasts have been done which indicates that like coastal fisheries, deep sea fisheries can also be of much commercial and economic value.

Carp Culture

Carp are various species of oily freshwater fish of the family Cyprinidae, a very large group of fish native to Europe and Asia. Carp is a large freshwater fish native to central Asia.

Introductions in many countries have helped to make carp the most widely distributed freshwater fish in the world. They are highly cultured and domesticated in aquaculture for food and ornamental purpose.

Freshwater fishes cultured in India are mainly major carp, minor carp, exotic carp, and other fishes. Fishes like Katla, mrigal, and rohu (rui) are 3 major carps of India. A lot of research, hybridization, reduce breeding have been carried out with carps distressfully.

Indian major carp grow fast and can reproduce even in artificial ponds. v. Minor carps are smaller in size than major carp. They do not produce as many eggs as major carp.

Kalbasu, bata,punti, etc., are minor carps. minor carp fishes grow to a size of 30- 100 2cm. with an average weight of 1 to 1.5 kg. The rate of egg production is very low in these fishes.

When the indigenous fishes are not favored for culture due to economic viability, exotic breeds are selected and cultured. These fishes yield nutritious food and earn foreign exchange.

Examples of exotic carp are silver carp, grass carp, and common carp. Other common freshwater fishes are – lata, maguro, single, koi, Tangra, Boal, tilapia, panda, bhetki, etc. However, these fishes are not carp.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production crap fish

 

Indian Carp culture: Indian aquaculture has been,n growing at a fast pace over the last two d^cpdes, with freshwater aquaculture contributing over 95% of the production.

The three major carps cultured in India, namely, Katla (Catla catla), rohu (Labeo rohita), and mrigal (Cirrhinus mrigala), contribute as much as 87 percent of the total Indian aquaculture production.

Three exotic carp were also introduced, namely, silver carp (Hypophthalmichthys molitrix); grass carp (Ctenopharyngodon idyllic), and common carp (Cyprinus carpio).

There are also several other medium and minor carp species, namely kalbos(Labeo calabash) bata (L. bata), and Puntif Puntius sarana), which are important in aquaculture.

Among catfishes, major (Ciarias batrachus) is the only species that is widely cultured, while the catfish, Singh (Heteropneustes fossilis) is cultured to some extent in the eastern states.

The finfish species of importance include climbing perch koi (Anabas testudineus), lata (Channa striata), and tilapia (Oreochromis mossambicus).

Preparation of pond

Pond preparation involves making the ponds weed and predator-free and generating adequate natural food for the survival and growth of fish.

Spawning: Because of constant temperature and favorable weather conditions, carps spawn all year round in India. Spawning takes place early in the morning when the water surface cools down to about 18 degrees.

The female carp swims near the water’s surface followed by the male carp in nuptial swimming and rubbing each other’s bodies. The female lays an egg and the male releases its milt and the eggs are fertilized.

Three days after fertilization, the eggs begin to hatch. The newly hatched larva (seedling) is about 5.5 mm long, delicate, and transparent, with a yolk sac attached to the belly.

It rarely swims but settles on the bottom or on some floating object. On the second day, the larva starts swimming, and on the third-day swims actively from surface to bottom.

During these stages, the larva or fry gets its nourishment from the yolk sac, which disappears on the third day and the fry now must search for food and eat.

Supplementary fry- feed in the form of hard-boiled egg yolk or powdered milk can be applied on the water surface at this time. When the fry grows slightly larger, about the size of a finger, it is called a fingerling.

Nursery ponds are constructed to rear carp fry or larvae. A normal-sized nursery pond measures 5 x 10 m, with a depth of 0.5 m. Before filling up the water the pond should be cleaned thoroughly to get rid of predators and parasites that may be destructive to the larvae. About 1,500 to 3,000 fries can be stocked in the nursery pond.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production winnowing prepation of pond

Food processing techniques for Class 8 students

Rearing ponds where adult carp are cultured until they reach marketable size, are needed, which have dimensions of 15 x 50 m and depth of 1.5 to 2 m.

Rearing ponds should also be thoroughly cleaned before filling them with water. This is done by exposing the bottom and letting it dry thoroughly.

The next step involves the application of fertilizers, which encourages the growth of aquatic plants, moss, and algae, which are important natural food and also lead to the growth of microfauna.

Manure in the form of chicken dropping is the most commonly used being cheaper and more readily available in large quantities. When carp fry reaches a length of about 5 to 7 cm, they are transferred from the nursery pond to the rearing pond and allowed to grow to the adult stage.

Stocking ponds: Ponds are stocked with fish fries of the appropriate size. Fingerlings over 10 cm in size are recommended for stocking in culture ponds.

In composite fish farming, a combination of six species is cultured, namely, Katla, rohu, mrigal, and exotic carp like silver carp, grass carp, and common carp.

Supplementary feeds like groundnut oil cake and rice bran are fed to fishes during culture. At the end of the culture period of say 12 months, the fish will reach the marketable size and fetch attractive prices.

Aeration may be done mechanically to increase the concentration of dissolved oxygen in ponds, by paddle wheel aerators, aspirator aerators, and submersible pond aerators. It is also necessary to replace a certain amount of water at regular intervals.

Harvesting

Harvesting of fish is usually done after a culture period of 10 months to one year. However, fish attaining the marketable size can be harvested periodically depending on several factors,

which also reduces the pressure of density in the ponds and thereby provides sufficient space for the growth of fish.

Induced breeding of carps: Induced fish farming has allowed farmers to breed and raise species that do not naturally reproduce in captivity,

manipulate the timing of reproduction to suit production cycles, get fish to spawn on a predetermined date, and fertilize and incubate eggs under hatchery conditions.

The strategy is to inject the fish with one or more naturally occurring reproductive hormones or synthetic analogs to manipulate the maturation of gonads and ovulation.

Sewage-fed fishery: Increasing population, industrialization, and urbanization have created problems in the form of waste disposal.

Wastes arise from virtually all forms of human activities. The common means of disposal of these materials is to dump them outside the village or city limits, to burn them, or to discharge them into ponds and rivers.

But in recent times things have changed. The use of waste for productive purposes has generated a new idea of waste management. Sewage is a rich nutrient resource, cheaply available around big towns and cities.

It can be well-utilized: for fertilizing paddies, fishponds, and horticulture crops. Waste recycling also helps in maintaining a clean environment.

For fish cult urn sewage water from stabilizing tank well as the water after dilution can be utilized. Air-breathing fishes are more suitable to be cultured In sewage treatment ponds as they can survive In water with lesser dissolved oxygen content.

Fish like maguro, single, lata, tilapia, grass carp, etc., are the species of choice to be considered for culture in sewage-treated ponds.

Numerous species of fish are farmed in the sewage-fed ponds called burls In the East Kolkata wetlands.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production induced breeding of craps

 

Nutritional value of fish

Fish Is a food of excellent nutritional value, providing high-quality protein and a wide variety of vitamins and minerals, including vitamins A and D, phosphorus, magnesium, selenium, and Iodine in marine fish.

Its protein – like that of meat – is easily digestible and favorably complements dietary protein provided by cereals and legumes that are typically consumed in many developing countries.

Fishes may be classed as either whitefish or oily fish. Whlteflsh, such as rohu, Katla, mrigal, etc, contain very little fat (usually less than 1%) whereas oily fish, such as English, panda, etc, contain between 10-25%.

Human food and its sources for Class 8

The latter, as a result of Its high-fat content, contains a range of fat-soluble vitamins (A, D, E, and K) and essential fatty acids, all of which are vital for the healthy functioning of the body.

Experts agree that, even in small quantities, fish can have a significant positive impact on improving the quality of dietary protein by complementing the essential amino acids that are often present in low quantities in vegetable-based diets.

But recent research shows that fish is much more than just an alternative source of animal protein. Fish oils in fatty fish are the richest source of a type of fat that is vital to normal brain development in unborn babies and infants. Without adequate amounts of these fatty acids, normal brain development does not take place.

Poultry farming

Poultry farming is the raising of domesticated birds such as chickens, ducks, turkeys, and geese, for the purpose of farming meat or eggs for food. Poultry is farmed in great numbers with chickens being the most numerous.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production polutry farming

 

Advantages of Chicken farming

  1. The initial investment is a little lower than layer farming.
  2. The rearing period is 6-7 weeks only.
  3. More flocks can be taken in the same shed.
  4. Broilers have high feed conversion efficiency i.e. least amount of feed is required for unit body weight gain in comparison to other livestock.
  5. Faster return from the investment.
  6. Demand for poultry meat is more compared to sheep/goat meat.
  7. Important terminologies associated with poultry

Breed: Birds with a common origin, having specific characteristics, such as body shape, that distinguish them from other groups within the same species.

Strain: Chicks having specific characteristics, produced in specific farms by breeding.

Variety: The subdivisions of breeds based on specific characteristics, for example- white Leghorn, brown Leghorn, etc.

Chick: Young chicken of either sex from day 1 to about 5-6 weeks of age.

Grower: Chicken of either sex from 6 weeks to 6 months of age.

Cock: A mature male chicken.

Cockerel: A male chicken from day 1 to about 1 year of age.

Hen: A mature female chicken.

Pullet: A female chicken less than one year of age.

Fowl: Generally refers to larger birds.

Broiler/ Fryer: A young bird of either sex, usually of meat-type breeds up to 8-10 weeks of age and weighing 1.5-2.5 kg. The term broiler is applied to chicks that have especially been bred for rapid growth.

  1. Broiler strains are based on hybrid crosses between Cornish White, New Hampshire, and White Plymouth Rock.
  2. In broiler production there are two main production phases:
  3. keeping of parent stock and production of day-old-chicken and
  4. Growing and finishing of broilers.

Layers: Layers are efficient egg producers, breeds used for egg production in the industrial production system are almost entirely based on the White Leghorn and Rhode Island Red.

  1. Selection and crossbreeding techniques have resulted in productive laying hens producing 15 – 19 kg of eggs per year. In layer production,
  2. sometimes two phases of production are recognized:
  3. growing phase up to approximately 140 days; and
  4. productive phase from 140 – 560 days.

 

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production eggs

 

Culling: The process of eliminating undesirable or non-reproductive animals.

Litter: The accumulation of materials, such as hay, sawdust, etc., to form the bed or floor of an animal farm.

Rooster: A young chick of meat type, weighing more than 1.5 kg.

Mash: A form of completely balanced feed that is finely ground and mixed so that birds can easily consume them and got proper nourishment.

Different Breeds Of Chicken

Different breeds are classified in different ways-

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Example- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According To Utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

3. According To Weight

Light breed: These breeds have body weights of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have body weights of more than 3 kg. Example- Aseel, Brahma, etc

According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

1. According to a place of origin

Mediterranean breeds: They originated in Europe, by the side of the Mediterranean Sea. They are small birds with lightweight but mature early and start egg laying. Examples- leghorn, Minorca, etc.

American breeds: The breeds originated in North America, due to hybridization with different Asiatic and Mediterranean breeds. They yield a considerable good amount of flesh and egg. Examples- are Rhode Island Red, New Hampshire, Plymouth Rock, etc.

English breeds: They are popular for their meat. Examples- Sussex, Australia, etc.

Asiatic breeds: These breeds originated in Asia. A few important ones are – Brahma, Cochin, etc. Indian indigenous breeds are – Aseel, Chittagong, Ghagus, etc.

2. According to the utility

Laying breed: They lay about 220 or more eggs per year. Example- Leghorn.

Table breed or Meat breed: They produce a good amount of flesh. Examples- Aseel, Cochin, etc.

Dual breed: They produce both egg and flesh in moderately good amounts. Examples- Rhode Island Red, New Hampshire, etc.

According to weight

Light breed: These breeds have a body weight of about 2-3 kg. Example- Leghorn.

Heavy breed: These breeds have a body weight of more than 3 kg. Example- Aseel, Brahma, etc

4. According to broodiness

Sitter: They sit on their eggs i.e., the mother incubates the eggs. Examples- Brahma, Aseel, etc.

Non-sitter: The mothers do not sit on their eggs. Eggs are generally incubated in artificial incubator machines. Examples- Leghorn, Minorca, etc.

Different systems of fowl or chicken farming Generally different systems of farming are followed by poultry keepers. These may be-

  1. Free range or extensive system
  2. Semi-intensive system
  3. Intensive system:
  4. Battery cage system,
  5. Deep litter system.

1. Free range system

Free-range poultry farming consists of poultry permitted to roam freely instead of being contained in any manner. A free-range chicken must have daytime access to open-air runs for at least half of their life.

Free-range chickens grow slowly. Free-range poultry production requires that the poultry have access to the outside. The birds are to be protected from predatory animals and intruders. At present, due to several disadvantages and a shortage of space, this method is almost obsolete.

2. Semi-intensive system

This system is adopted where the amount of free space available is limited. It is necessary to allow 20-30 square yards per bird of outside run.

The birds are kept in a large enclosed area during the day time and are kept in adjacent farmhouses during the night and in unfavorable weather conditions.

3. Intensive system

This system is usually adopted where land is limited. In this system, the birds are confined to the house entirely with no access to the land outside.

The intensive system may be of the following types-

Battery cage system: Battery cages are a housing system used for various animal production methods, but primarily for egglaying hens.

The name arises from the arrangement of rows and columns of identical cages connected together, sharing common divider walls, as in the cells of a battery.

In a battery cage, the rate of food and water, and the duration and intensity of light are tightly controlled. There is no access to the natural environment, nor any opportunity to conduct natural behaviors such as perching, dust bathing, wing flapping or nesting.

Environmental conditions are automatically controlled, including light duration, which mimics summer day length. This stimulates the birds to continue to lay eggs all year round.

Advantages

  1. A greater number of birds is reared per unit of area
  2. Facilitates correct maintenance of record
  3. Helps in identifying poor producers and prompt culling
  4. It helps in the production of clean eggs
  5. Easy control of parasitic disease
  6. Prompt steps to control feed wastage.

The cage method of housing is ideal for the area with moderate climate conditions where the day temperature in summer does not high and the temperature does not fall too low.

Egg production of the caged layer was reported to be more than those kept in a deep litter system.

Deep litter system: Deep litter system is commonly used all over the world. Litter is the substance that is used for farm animals to sleep on.

In the deep litter system, the poultry birds are kept in large pens of up to 250 birds each, on the floor covered with litter like straw, sawdust, or dried leaves up to a depth of 6-8 inches.

Deep litter is a method of chicken waste management that calls for droppings and bedding material to compost inside the chicken coop instead of being cleaned out and replaced regularly.

With the deep litter method, a carbon-based litter absorbs nitrogen from chicken droppings, which ferments in an odor-free process to produce rich, valuable humus just as in a traditional compost pile.

WBBSE Solutions For Class 8 School Science Chapter 8 Human Food And Food Production different system of fowl or chicken farming..

Advantages

  1. It is economical, hygienic, comfortable, and safe for birds
  2. Controls diseases and vices
  3. It increases the efficiency of production
  4. Materials such as paddy husks, sawdust, dried leaves, chopped straw, and groundnut kernels depending upon the availability can be used as litter materials.
  5. Nutritional value of chicken
  6. Naturally low in sodium.
  7. 100 grams of skinless boneless chicken has 31 grams of protein, or more than half the recommended daily allowance.

A good source of niacin, which aids in metabolism; vitamin B6, important to the immune system and blood sugar; biotin, which aids in cell growth; vitamin Bu, involved in nerve and red blood cell maintenance.

  1. Nutritional value of egg
  2. Contain one of the highest quality proteins of any food.
  3. A large egg contains about 70 calories and 6 grams of protein.
  4. A single egg contains 13 essential nutrients.
  5. Egg proteins contain time-release energy which helps maintain blood glucose levels and makes people feel full and energized longer.

 

WBBSE Class 8 School Science Chapter 7 The Microbial World LAQs

WBBSE Chapter 7 The Microbial World Long Answer Questions

Question 1. What are microbes? Where they are found? What are the major classes of microbes?
Answer:

Microbes:

The term microbe is short for microorganisms, which means small organisms visible only under microscopes. A microbe is any living thing that is too tiny to be seen with the naked eye.

Microbes are the oldest form of life on earth. They may live as individuals or cluster together in communities. Microbes live in the water you drink, the food you eat, and the air you breathe.

WBBSE Class 8 School Science Chapter 7 The Microbial World LAQs

Right now, billions of microbes are swimming in your belly and mouth, and crawling on your skin Don’t worry; over 95% of microbes are good for you.

Microbes include bacteria, viruses, fungi, algae, and protozoa. These single-cell organisms are invisible to the eye, but they can be seen with microscopes.

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World Mircobes

Classification of Microbes

The term microbe is short for microorganism, which means small organisms. To help people understand the different types of microbes, they are grouped or classified in various ways.

Microbes are very diverse and represent all the great kingdoms of life. In fact, in terms of numbers, most of the diversity of life on earth is represented by microbes.

Here is an outline of the major groups of microorganisms:

  1. Viruses
  2. Bacteria (Monera)
  3. Algae (Plantae)
  4. Fungi
  5. Protozoa (Protista)

Read And Learn More WBBSE Solutions For Class 8 School Science Long Answer Type Questions

Viruses

A virus is acellular and composed basically of a tiny bundle of genetic material (either DNA or RNA) carried in a shell called the viral coat.

They have no boundary wall, cytoplasm, or nucleus. Thousands of different viruses, which come in many shapes, are parasites and disease-causing agents.

Viruses are found on or in just about every material and environment on Earth from soil to water to air. Viruses do not show most of the characteristics of living things outside the living host.

But if they come into contact with a suitable plant, animal, or bacterial cell, they spring into action. They infect and take over the cell like pirates hijacking a ship.

Viruses exist to reproduce only. To do that, they have to take over suitable host cells. The new viral genes then come together and assemble into whole new viruses.

The new viruses are either released from the host cell without destroying the cell or eventually build up to a large enough number that they burst the host cell.

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World virus

WBBSE Class 8 Microbial World Long Answer Questions

Question 2. What are bacteria? Classify them according to the structure.
Answer:

Bacteria:

Bacteria consist of only one cell, but they are a very complex group of living things. Unlike viruses, bacteria feed, move, and respire as well as reproduce on their own.

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World Shape of bacteria

 

Some bacteria can live in temperatures above the boiling point and in cold below the freezing point. There are thousands of species of bacteria.

Bacteria are classified into 5 groups according to their basic shapes: spherical (cocci), rod (bacilli), spiral (spirilla), comma (vibrios), or corkscrew (spirochaetes). They can exist as single cells, in pairs, chains, or clusters.

Some bacteria can make their own food from sunlight, just like plants. Also like plants, they give off oxygen. Other bacteria absorb food from the material they live on or in. They have no membrane-bound cell organelles.

A single teaspoon of soil contains more than a billion (1,000,000,000) bacteria. Bacteria reproduce by binary fission. In this process the bacterium, which is a single cell, divides into two identical daughter cells. Binary fission begins when the DNA of the bacterium divides into two (replicates).

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WBBSE Solutions For Class 8 Maths WBBSE Class 8 History Notes
WBBSE Class 8 History Multiple Choice Questions WBBSE Solutions For Class 8 History
WBBSE Solutions For Class 8 Geography

 

Differences between bacteria and viruses:

Because bacteria and viruses cause many of the diseases we’re familiar with, people often confuse these two microbes. But viruses are entirely different from bacteria.

For one thing, they differ greatly in size. The biggest viruses are only as large as the tiniest bacteria. Another difference is their structure. Bacteria are complex compared to viruses.

A typical bacterium has a rigid cell wall and a thin, rubbery cell membrane surrounding the fluid, or cytoplasm, inside the cell.

A bacterium contains all of the genetic information needed to make copies of itself—its DNA—in a structure called a chromosome. In addition, it may have extra loose bits of DNA called plasmids floating in the cytoplasm.

Bacteria also have ribosomes, necessary for copying DNA so bacteria can reproduce. Some have threadlike structures called flagella that they use to move.

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World bacteriophage

Chapter 7 The Microbial World Detailed Answers WBBSE

Question 3. What are protozoa? Write about harmful protozoa. What is Achaea?
Answer:

Protozoa:

Protozoa are single-celled organisms having one or more nuclei. They come in many different shapes and sizes ranging from an Amoeba which can change its shape to its fixed shape and complex structure.

They live in a wide variety of moist habitats including freshwater, marine environments, and soil. They can live freely or in a colony.

Protozoa mainly feed on bacteria, but they also eat other protozoa, and sometimes fungi. Some protozoa absorb food through their cell tissues.

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World Protozoa

 

Others, surround food and engulf it. Others have openings similar to mouth pores into which they sweep food.
Protozoa can be classified into three general groups based on their shape. One group is the Ciliates, which are generally the largest protozoa. The second group is the Amoebae.

The nutrients from living or dead organic matter that they grow on. They absorb simple, easily dissolved nutrients, such as sugars, third group is the Flagellates, which are usually the smallest of the protozoa.

Most protozoa do us no harm. But there are a few that cause diseases. One type of amoeba can live in human intestines. It feeds on red blood cells and causes a disease known as dysentery.

Another species of protozoa can sicken hundreds of thousands of people when it gets into the tap water. Perhaps the best-known deadly protozoa cause malaria, a terrible disease that leads to about 800,000 deaths each year worldwide.

WBBSE Class 8 Science Long Answer Solutions

Question 4. What is parasitism? Write about parasitic microbes.
Answer:

Parasitic:

They derive their nutrition from the plants and animals on which they grow. Certain enzymes are produced by them which decompose or kill the protoplasm of the host cells.

The interrelationship between the parasitic microbe and the host is called parasitism. Such effects of the parasites on the host become visible to the naked eye as disease symptoms.

Many well-known diseases of human beings like typhoid, tetanus, tuberculosis, pneumonia, and many others are due to parasitic bacteria.

Microbes are also known as pathogenic bacteria. Some bacteria grow well only in the presence of oxygen, while others grow well in absence of oxygen. The former is known as aerobes and the latter are anaerobes.

Question 5. What are saprophytes? Write a note about saprophytic microbes.
Answer:

Saprophytic:

They grow on dead and decaying plants and animals, dung,’ rotten wood, stagnant water, and many other decaying substances rich in organic matter.

Certain enzymes secreted by the bacteria decompose the complex organic substances of the substrate, converting them into simpler ammonium compounds.

They cause decay and therefore are also known as putrefying bacteria. The souring of milk, the manufacture of cheese, the preparation of butter from milk, and vinegar from sugarcane juice, are various processes completed by the action of certain specific saprophytic bacteria.

Zygomonas ferments glucose-producing alcohol, lactic acid, and carbon dioxide, and plays a significant role in the wine industry.

Acetobacter oxidizes organic compounds to organic acids such as lactic acid thus having a significant role in the vinegar industry. Lactobacillus converts sugars into lactic acid. Canned food is spoiled by some Bacillus and Clostridium bacteria.

WBBSE Class 8 Science Important Long Answer Questions

Question 6. What is symbiosis? Explain the term with examples from microbes.
Answer:

Symbiotic:

Symbiosis is the phenomenon by which two organisms maintain a relationship with each other to be mutually benefitted. In symbiotic mode, organisms develop a special relationship with certain other organisms to obtain nourishment.

Organisms involved in this type of relationship are called symbionts. Rhizobium bacteria is a striking example of this type.

They occur in root nodules of leguminous plants and help in fixing the free nitrogen of the atmosphere in the soil for the plants which in return provides carbohydrates and protection to the bacteria.

They are also called nitrogen-fixing bacteria and add to the fertility of the soil. Azotobacter and Clostridium are other examples of nitrogen-fixing bacteria.

They are found in chalky soil and obtain energy from the carbohydrates present in the soil. The energy so obtained is used in fixing atmospheric nitrogen into amino acids in the soil which react with the calcium salts, forming nitrites and thereafter nitrates.

Lichens form a very good example of a symbiotic relationship. Lichens are formed by the symbiotic relationship between algae and fungi sharing a single colony.

Fungus provides water, nutrients, and shelter in the form of the network formed by mycelium. Algae synthesize the food for the entire colony through the process of photosynthesis.

Question 7. Write about various microbial habitats with suitable examples.
Answer:

Microbial Habitat:

Microbes live in almost every nook and corner you can think of, from 20 miles beneath the Earth’s surface to 20 miles overhead. They live at temperatures less than -20 degrees Celsius to temperatures hotter than the boiling point.

Microbes thrive on a huge range of food including oil and toxic wastes. Every time you walk on the ground you step on billions of microbes.

Microbes live in the soil, on rocks, inside roots, buried under miles of earth, in compost piles, and toxic waste all over the earth’s surface.

Microbes are found in boiling hot springs and on frozen snow fields. Most animals interact with microbes in important ways, and all animals, as well as all plants and fungi, depend on microbes for their survival.

Microbes live in their digestive systems, in their mouths, and on their skin. Microbes are important for the good health of animals.

Animals provide microbes with food and shelter. That is why animals are called “hosts” to microbes. For example, cows depend on microbes for their food.

Cows and other animals called ruminants have special stomachs called rumens which are host to billions of microbes that help these animals survive.

Also, we depend on microbes to clean up our environment. Without microbes to get rid of all the dung from animals, the world would be a really smelly place. Microbes make this world a cleaner place.

Long Answer Format for Class 8 Microbial World

Question 8. What is lichen? Mention some economic importance of lichens.
Answer:

Lichen:

A lichen is a composite organism that emerges from algae or cyanobacteria (or both) living among filaments of a fungus in a mutually beneficial (symbiotic) relationship.

The fungus benefits from the symbiotic relationship because algae or cyanobacteria produce food by photosynthesis. The algae or cyanobacteria benefit by being protected from the environment by the filaments of the fungus,

  1. which also gathers moisture and nutrients from the environment, and (usually) provides an anchor to it.
  2. Economic importance of Lichens:
  3. Lichens are used in the tanning of leather.
  4. Important dyes are prepared from lichens for use in woolen and silken clothes.
  5. Lichens like Evernia is used in cosmetics and perfumes.
  6. Lichens are indicators of pollution
  7. Lichens play important role in soil formation.

Question 9. Write the full form of DOTS. What is food poisoning? Mention the names of two bacteria that cause food poisoning. What are the symptoms of food poisoning?
Answer:

DOTS:

DOTS stands for Directly Observed Treatment, short course.

The disease caused due to the presence of a large number of microorganisms (like bacteria and fungi) in the food or due to the presence of toxic substances in food formed by the action of microorganisms, is called food poisoning.

Bacteria Food poisoning
Clostridium botulinum Botulism
Salmonella Typhimurium Salmonellosis

 

The Microbial World WBBSE Class 8 Comprehensive Answers

Question 10. Mention two types of yeast that are used as food. Name two microbial vitamins along with their sources. Name a disease-causing microorganism in animals.
Answer:

Two types of yeast that are used as food:

Yeast type Organism used Purpose
Baker’s Yeast Saccharomyces cerevisiae Used to leaven bread
Food Yeast Torulopsis utilize Used as a dietary supplement in deficient diets

 

Microbial vitamin Source
Vit. B12 Bacillus coagulans
Riboflavin Ashbya gossypii

Anthrax un animals is caused by bacillus anthracis