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.

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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

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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

 

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 SAQs

Chapter 7 The Microbial World Short Answer Type Questions

Question 1. What are microbes?
Answer:

Microbes:

The term microbe is short for microorganisms, which means extremely diverse small organisms. A microbe is any living organism that spends its life at a size too tiny to be seen with the naked eye.

Microbes include bacteria and archaebacteria, protists, and some fungi. Viruses and the recently discovered prions are also considered microbes.

Question 2. What is a virus?
Answer:

Virus:

A virus is an acellular infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.

Question 3. What are bacteria?
Answer:

Bacteria:

Bacteria are microscopic prokaryotic organisms whose single cells have neither a membrane-enclosed nucleus nor other membrane-enclosed organelles like mitochondria and chloroplasts.

Question 4. What are protozoa?
Answer:

Protozoa:

The name ‘proto-zoa’ literally means ‘first animals’ and early classification systems grouped the protozoa as members of the animal kingdom.

However, they were recognized as a discrete assemblage based on their unicellularity and were assigned to the kingdom Protista. Protozoa are eukaryotic organisms that exist as structurally and functionally independent individual cells.

Question 5. What are fungi?
Answer:

Fungi:

A fungus (plural: fungi) is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms.

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

These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, protists, and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants and some protists.

Question 6. Which contains cellulose, unlike the cell walls of bacteria What are algae?
Answer:

Algae (singular: alga) are any of numerous groups of chlorophyll-containing, mainly aquatic eukaryotic organisms ranging from ‘ microscopic single-celled forms to multicellular forms, distinguished from plants by the absence of true roots, stems, dried Leaves.

Question 7. Write two characteristics of the virus.
Answer:

Characteristics of the virus:

Obligate intracellular parasite composed of nucleic acid (either DNA or RhlA) and protein coat.

Multiply inside living cells using the host cell machinery.

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. State for example the useful and harmful role of viruses.
Answer:

Useful Role Of Viruses:

Viruses have very clever ways of attacking all types of cells, including bacteria. Scientists are trying to find ways of using these viruses to kill bacteria, instead of antibiotics.

Harmful Role Of Viruses:

Viral infections can cause disease in humans, animals, and even plants. Respiratory viruses can induce rubella, measles, mumps, influenza, and the common cold.

Question 9. How viral infection can be prevented?
Answer:

Prevention Of Viral Infection:

Viral infections can cause disease in humans, animals, and even plants. However, they are usually eliminated by the immune system, conferring lifetime immunity to the host for that virus.

Antibiotics do not affect viruses, but antiviral drugs have been developed to treat life-threatening infections. Vaccines that produce lifelong immunity can prevent some viral infections.

Chapter 7 The Microbial World Short Answer Questions

Question 10. Write two characteristics of bacteria.
Answer:

Characteristics Of Bacteria:

  1. Prokaryotic organisms with cytoplasm and nucleic acids (both DNA and RNA).
  2. Membrane-bound cell organelles are absent.

Question 11. Write briefly about useful bacteria.
Answer:

Useful Bacteria:

Some bacteria degrade organic compounds for energy, and without bacteria, the earth would have no soil in which to grow plants.

Bacteria living in the gut(E. coli, Lactobacillus, Streptococcus, etc) can help animals break down food. These so-called ‘good bacteria help maintain the conditions necessary for food digestion.

Ammonifying bacteria (eg. Bacillus ramosus) release ammonia in soil by decay and putrefaction. Nitrifying bacteria (Nitrobacter) convert ammonia to nitrites.

Symbiotic (eg. Rhizobium) or nonsymbiotic (eg. Azotobacter) bacteria fix up atmospheric nitrogen into the soil to increase soil fertility.

  1. Bacitracin, a source of antibiotics, is extracted from Bacillus subtilis.
  2. Bacillus subtilis, Clostridium tertium etc help in extraction of fibre from jute, hemp and coir.

For the curing of tea and tobacco, My coccus cardigans and Bacillus megatherium are used.

Question 12. Write briefly about harmful bacteria.
Answer:

Harmful Bacteria:

There are many types of harmful bacteria, some of which are deadly, while others only cause minor illnesses. One of the most dangerous is Yersinia pestis, which caused the bubonic plague, and which still afflicts small portions of the world’s population.

A less dangerous, but still inconvenient, form is Campylobacter, which is responsible for most cases of food poisoning, causing severe intestinal discomfort and often vomiting.

Other bacteria may be an inconvenience if treated, but deadly if left on their own, such as the different types of Streptococcus that are responsible for strep throat and pneumonia.

Denitrifying bacteria convert nitrates to free nitrogen gas in soil with excessive water and poor aeration resulting in a reduction of soil fertility, eg. P. denitrificans, etc.

Food poisoning is caused by Clostridium botulinum, Micrococcus pyogenes, etc.

Bacteria also cause some harmful plant diseases like the soft rot of potatoes, angular leaf spots of cotton, plant tumors, etc.

WBBSE Class 8 School Science Chapter 7 The Microbial World SAQs

Question 13. State two characteristics of protozoa.
Answer:

Characteristics of protozoa:

  1. Protozoa are eukaryotic microorganisms lacking the capability of photosynthesis.
  2. Protozoa are notable for their ability to move independently (by pseudopodia/ cilia/ flagella), a characteristic found in the majority of species.

Question 14. Name the microbes that are employed in
Answer:

  1. conversion of lactose to lactic acid
  2. synthesis of Vit. B12
  3. sewage treatment
  4. tanning of leather
  5. production of protein-rich powder or protein cakes
  6. Lactobacillus (bacteria)
  7. Clostridium (bacteria.)
  8. Chlorella or Chlamydomonas (algae)
  9. Lichens
  10. Yeast (fungi)

Question 15. Write briefly about useful protozoa.
Answer:

Useful Protozoa:

Some protozoans live in the body of other organisms and help them. Termites, for example, have protozoans (Triconympha) living in their body.

  1. The protozoans digest the cellulose in the wood eaten by termites and convert it into carbohydrates that the termites can use.
  2. A large number of protozoa living in polluted water feed upon waste organic matter and thus purify it.
  3. The skeletal deposits of foraminiferans and radiolarians are associated with oil deposits.

Question 16. Write briefly about harmful protozoa.
Answer:

Harmful Protozoa:

Some protozoans cause diseases. The protozoan Entamoeba causes amoebiasis (amoebic dysentery) in human beings, while Plasmodium causes malaria.

  1. Trypanosoma, a parasitic protozoan that lives in the bloodstream of human beings, cattle, and other animals, causes a dangerous disease called sleeping sickness.
  2. About 200-300 varieties of protozoa live in the soil, feed on nitrogen-fixing bacteria, and reduce the fertility of the soil.
  3. Drinking water in natural conditions is made unpalatable by the reproduction of some free-living protozoa in it.
  4. Protozoans living in the gut of termites indirectly help in the destruction of wooden articles.

WBBSE Class 8 Science Important Short Answers

Question 17. State two characteristics of fungus.
Answer:

Characteristics of fungus:

Most fungi grow as tubular filaments called hyphae. An interwoven mass of hyphae is called mycelium. The walls of hyphae are often strengthened with chitin.

Fungi are not capable of producing their own food (due to lack of chloroplastid), so they get their nourishment from other sources.

Question 18. Write briefly about useful fungi.
Answer:

Useful Fungi:

Fungi, together with bacteria, are responsible for most of the recycling which returns dead material to the soil in a form in which it can be reused.

  1. Fungi are also important directly as food for humans. Many mushrooms are edible and different species are cultivated for sale worldwide.
  2. Yeast is used in baking bread, Penicillium came Berti is used in cheese to give flavor and shine to butter, etc.
  3. Fungi are used in the biological control of pathogenic bacteria and certain nematodes.

Question 19. Write briefly about harmful fungi.
Answer:

Harmful Fungi:

Some fungi are harmful as they cause disease: rusts and smuts on farm crops and orchards, athletes’ feet, oral thrush, ringworm disease, etc. Aspergillus, and Rhizopus infect food grains and make them unfit for consumption.

Question 20. State two characteristics of algae.
Answer:

Two Characteristics Of Algae:

  1. Algae are eukaryotic organisms that have no roots, stems, or leaves.
  2. Algae have chlorophyll and other pigments for carrying out photosynthesis.

Question 21. What are harmful algae?
Answer:

Harmful Algae:

Phytoplankton blooms, micro-algal blooms, toxic algae, red tides, or harmful algae, are all terms for naturally occurring phenomena.

Several hundred species of micro-algae are reported at times to form mass occurrences, so-called blooms. Nearly one-fourth of these species are known to produce toxins.

Short Answer Questions for Class 8 Microbial World

Question 22. Write briefly about useful algae.
Answer:

Useful Algae:

Humans use algae as food, for the production of useful compounds, as biofilters to remove nutrients and other pollutants from wastewaters to assay water quality, as indicators of environmental change, in space technology, and as laboratory research systems.

  1. Nostoc and Anabaena are good nitrogen fixers.
  2. Chara is used as larvicidal to destroy mosquito larvae.
  3. Chlorella is an antibiotic extracted from chlorella.

Question 23. What is a vaccine?
Answer:

Vaccine:

A vaccine is a biological preparation that provides active acquired immunity to a particular disease.

Question 24. What is immunity?
Answer:

Immunity:

In biology, immunity is the balanced state of having adequate biological defenses to fight infection, disease, or other unwanted biological invasions, while having adequate tolerance to avoid inflammation, allergy, and autoimmune diseases.

Question 25. What is vaccination?
Answer:

Vaccination:

Vaccination is the administration of antigenic material (a vaccine) to stimulate an individual’s immune system to develop adaptive immunity to a pathogen. Vaccines can .prevent or ameliorate morbidity from infection.

Question 26. What is an antigen?
Answer:

Antigen:

An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a foreign substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also be formed inside the body, as with bacterial toxins or tissue cells.

Question 27. What is an antibody?
Answer:

Antibody:

An antibody is a protein produced by the body’s immune system when it detects harmful substances, called antigens.

Question 28. What are antibiotics?
Answer:

Antibiotics:

Antibiotics or antibacterials are a type of antimicrobial used specifically against bacteria, and are often used in the medical treatment of bacterial infections.

They may either kill or inhibit the growth of bacteria. Several antibiotic agents are also effective against a number of fungi, and protozoans and some are toxic to humans and animals.

Question 29. What is symbiosis?
Answer:

Symbiosis:

Symbiosis is close and often long-term interaction between two or more different biological species. Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival.

For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own. Others are facultative, meaning that they can, but do not have to live with the other organism.

Question 30. What is parasitism?
Answer:

Parasitism:

Parasitism is a non-mutual symbiotic relationship between species, where one species, the parasite, benefits at the expense of the other, the host.

Question 31. What are saprophytes?
Answer:

Saprophytes:

Saprophytes are living organisms that feed on dead organic matter. They are considered extremely important in soil biology, as they break down dead and decaying organic matter into simple substances that can be taken up and recycled by plants. The term is usually used to refer to saprophytic fungi or bacteria.

Question 32. 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.

Question 33. What is the canning of food?
Answer:

Canning Of Food:

Canning is a method of preserving food in which the food contents are processed and sealed in an air-tight container.

Question 34. What is food preservation?
Answer:

Food Preservation:

Food preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), or other microorganisms (although some methods work by introducing benign bacteria or fungi to the food), as well as retarding the oxidation of fats that cause rancidity.

WBBSE Chapter 7 Microbial World Study Guide

Question 35. What is pasteurization?
Answer:

Pasteurization:

Pasteurization is a heat-treatment process that destroys pathogenic microorganisms in certain foods and beverages. It is named after the French scientist Louis Pasteur,

who in the 1860s demonstrated that abnormal fermentation of wine and beer could be prevented by heating the beverages to about 57° C for a few minutes.

Pasteurization of milk requires temperatures of about 63° C maintained for 30 minutes or, alternatively, heating to a higher temperature(72° C)and holding for 15 seconds (and yet higher temperatures for shorter periods of time).

Question 36. What is fermentation?
Answer:

Fermentation:

Fermentation is a metabolic process that converts sugar to acids, gases, and/or alcohol. It occurs in yeast and bacteria, but also in oxygen-starved muscle cells, as in the case of lactic acid fermentation.

Question 37. What is retting?
Answer:

Retting:

Retting is a process employing the action of microorganisms and moisture on plants to dissolve or rot away much of the cellular tissues and pectins surrounding bast-fiber bundles, and so facilitating the separation of the fiber from the stem.

To extract fine fibers from the jute plant, a small stalk is harvested for pre-retting. Usually, this small stalk is brought 2 weeks of harvesting time. If the fiber can easily be removed from the Jute hurd or core, then the crop is ready for harvesting.

Question 38. What is Nitrogen fixation?
Answer:

Nitrogen Fixation:

Nitrogen fixation is a process in which nitrogen in the atmosphere is converted into ammonium. Atmospheric nitrogen or molecular nitrogen

(NJ is relatively inert: it does not easily react with other chemicals to form new compounds. Nitrogen fixation, natural and synthetic, is essential for all forms of life because nitrogen is required to biosynthesize the basic building blocks of plants, animals, and other life forms.

Question 39. What are Nitrogen-fixing bacteria? Nitrogen-fixing bacteria are microorganisms capable of transforming atmospheric

Answer:

Nitrogen-Fixing Bacteria:

Nitrogen into fixed nitrogen, inorganic compounds usable by plants. More than 90 percent of all nitrogen fixation is affected by them.

Two kinds of nitrogen fixers are recognized: free-living (non-symbiotic) bacteria, including the Cyanobacteria (or blue-green algae)

Anabaena and Nostoc, and such genera as Azotobacter, and Clostridium; and mutualistic (symbiotic) bacteria such as Rhizobium, associated with leguminous plants, and Spirillumlipoferum, associated with cereal grasses.

Question 40. What is nitrification?
Answer:

Nitrification:

Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. Nitrification is an important step in the nitrogen cycle in soil.

Short Answer Resources for Class 8 The Microbial World

Question 41. What is denitrification?
Answer:

Denitrification:

Denitrification is a microbially facilitated process of nitrate reduction (performed by a large group of heterotrophic facultative anaerobic bacteria) that may ultimately produce molecular nitrogen (NJ through d series of intermediate gaseous nitrogen oxide products.

Question 42. What is ammonification?
Answer:

Ammonification:

The process of ammonification is the result of the breakdown of organic matter such as dead animals and plants or waste materials like excrement.

This breakdown is accomplished by scores of microorganisms that utilize dead organic material for energy and produce ammonia and related compounds as a byproduct of their metabolisms.

Ammonification classically occurs in the soil, in an aerobic environment which gives the bacteria and other microorganisms oxygen to work with.

Question 43. What is the salting of food?
Answer:

Salting Of Food:

Salting is the preservation of food with dry edible salt. It is related to pickling (preparing food with brine, that is, salty water) and is one form of curing. It is one of the oldest methods of preserving food.

Question 44. What is pickling?
Answer:

Pickling:

Pickling is the process of preserving food by anaerobic fermentation in brine or vinegar. The resulting food is called pickle.

Question 45. What are methanogenic bacteria?
Answer:

Methanogenic Bacteria:

Methanogenic bacteria are a large and diverse group that is united by three features:

  1. they form large quantities of methane as the major product of their energy metabolism,
  2. they are strict anaerobes, (Hi) they are members of the domain archaea or archaebacteria.

Question 46. What is biogas?
Answer:

Biogas:

Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.

Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste, or food waste.

Biogas can be produced by anaerobic digestion with anaerobic bacteria, which digest material inside a closed system, or fermentation of biodegradable materials.

Biogas is primarily methane and carbon dioxide and may have small amounts of hydrogen sulfide. Biogas can be compressed, the same way natural gas is compressed to CNG, and used to power motor vehicles.

Question 47. Write the Differences between bacteria and virus
Answer:

The Differences between bacteria and virus:

Points of differences Bacteria Virus
Ribosomes  Present Absent
Cell wall Peptidoglycan/Lipopolysaccharide No cell wall, a Protein coat is present instead.
Living attributes Living organism Opinions differ on whether viruses are a form of life or organic structures that interact with living organisms.
Number of cells Unicellular; one cell No cells; not living
Structures DNA and RNA float freely in the cytoplasm. Has a cell wall and cell membrane. DNA or RNA is enclosed inside a coat of protein.
Treatment Antibiotics Vaccines prevent the spread and anti-viral medications help to slow reproduction but cannot stop it completely.

 

WBBSE Class 8 Science Practice Questions on Microbes

Question 48. Write the differences between fungi and bacteria.
Answer:

The differences between fungi and bacteria:

  1. Fungi are eukaryotes while bacteria are prokaryotes.
  2. Bacteria are single-celled whereas most fungi are multicellular except for yeast.
  3. The compositions within their cell walls are different.
  4. Fungi are heterotrophs while Bacteria can be autotrophs or heterotrophs.
  5. Bacteria have 3 distinct shapes furg have various shapes.

Bacteria reproduce sexually via binary fission whereas fungi are capable of reproducing both sexually or asexually. (There is no hard and fast rule that the differences should always be written in columns.

The above answer is an example. However, students can arrange them according to columns, if instructed by their teachers.)

Question 49. Write the differences between algae and fungi.
Answer:

The differences between algae and fungi:

Algae Fungus
1. Cell wall is made up of cellulose. 1. Cell wall is made up of chitin.
2. Cells contain chloroplasts. Hence, these are green in color. 2. Cells do not contain chloroplasts. Hence, these are colorless.
3. These are autotrophic. 3. These are heterotrophic.
4. Cells are uninucleated. 4. Cells or hypha are uninucleated, binucleated, or coenocytic.
5. The reserve food is starch 5. The reserve food is glycogen.

 

Question 50. Write the similarities and dissimilarities between algae and protozoa.
Answer :

Some similarities are:

  1. They have nuclei and can reproduce by mitosis followed by cell division.
  2. Many in both groups are able to move.
  3. Like the algae, some protozoans, like Euglena, are able to do photosynthesis.
  4. Both belong to the kingdom Protista.
  5. Some differences are
Characteristics Algae Protozoa
Nutritional type Photoautotroph Chemoheterotroph
Multicellularity Some None
Cellular arrangement Unicellular, colonial, filamentous Unicellular
Food acquisition Diffusion Absorptive; ingestive (cytostome)
Characteristic Pigments Motility; some form cysts

 

Question 51. Write the differences between symbiosis and parasitism.
Answer:

The differences between symbiosis and parasitism:

Symbiosis Parasitism
1. It is a relationship in which two organisms live together in a manner that is beneficial to both. 1. It is a relationship between two organisms that is beneficial to one (the parasite) and harmful to the other (the host).
2. Each partner in the relationship is called a symbiont. 2. The organism which draws food is called the parasite and the one which provides food and shelter is called the host.
3. For example, the relationship between root nodules of leguminous plants and Rhizobium (N2 -fixing bacterium), E. coli present in the human intestine. 3. For example, Cuscuta is a parasitic plant. Plasmodium is a parasite in the body of man and mosquito.

 

Question 52. Write the differences between parasite and saprophyte.
Answer:

The differences between parasite and saprophyte:

Parasite Saprophyte
1. The organism, which depends upon other organisms for its nourishment and growth, is known as a parasite. 1. The organism, which grows on dead and decaying material for its growth, is known as a saprophyte.
2. It has intracellular digestion. 2. It shows extracellular digestion.
3. It causes harm to the organism. 3. It does not depend on a living host.

 

WBBSE Class 8 School Science Chapter 7 The Microbial World VSAQs

WBBSE Chapter 7 The Microbial World VSAQs

Question 1. What are microbes?
Answer:

Microbes:

Microscopic living organisms other than plants and animals.

Question 2. What is the whitish layer, formed on the surface of bread during the rainy season?
Answer:

It is a layer of fungus.

WBBSE Class 8 Quick Answers on Microbes

Question 3. What are the most primitive and ancient organisms found on earth?
Answer:

Microbes are the most primitive and ancient organisms.

Question 4. Name one anaerobic microbe.
Answer:

Yeast (or tetanus-causing pathogen) is an anaerobic microbe.

Question 5. What is the term used to denote the organisms living on dead and decaying organic matter?
Answer:

They are called saprotrophs.

WBBSE Class 8 Very Short Answer Questions Microbial World

Question 6. Which microbes can produce their food?
Answer:

Algae can produce their food.

WBBSE Class 8 School Science Chapter 7 The Microbial World VSAQs

Question 7. What are thermophilic bacteria?
Answer:

Thermophilic Bacteria:

They can grow and survive even at about 100X.

Question 8. What types of bacteria are found in hot springs?
Answer:

Types of bacteria are found in hot springs:

Thermophilic bacteria are found in hot springs.

Question 9. What is staining?
Answer:

Staining:

It is the process of coloring specimens for identification under a microscope.

Question 10. Which cell organelle is present in bacteria?
Answer:

Ribosomes are present in bacteria.

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

Question 11. State the characteristics of bacterial DNA.
Answer:

It is circular DNA, not enclosed within the nucleus.

Question 12. Name a locomotory structure of protozoa, other than pseudopodia.
Answer:

The locomotory structures may be cilia or flagella.

Chapter 7 The Microbial World WBBSE Answers

Question 13. What are the units of fungal mycelium?
Answer:

Units of fungal mycelium:

A large number of hyphae form mycelium

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
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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

 

Question 14. Give an example of a unicellular roundish fungus.
Answer:

Yeast is a unicellular, roundish fungus.

Question 15. Why fungi can not synthesize their food?
Answer:

Because they do not have chloroplasts in their cell.

Question 16. Name colonial algae.
Answer:

Colonial algae:

Volvox is a colonial alga.

Question 17. Why algae can synthesize their own food (autotrophic)?
Answer:

Because they have chloroplasts in their cytoplasm.

Question 18. Which microbes cause smallpox?
Answer:

Smallpox is caused by a virus.

Question 19. Which microorganisms do not have a nucleus and cytoplasm?
Answer:

Viruses do not have a nucleus and cytoplasm.

WBBSE Class 8 Science Very Short Answer Format

Question 20. What type of nucleic acid is found in viruses?
Answer:

The nucleic acid is either DNA or RNA.

Question 21. Which microbes show the characteristic of living only within the body of a host?
Answer:

Viruses behave like living only within the body of a host.

Question 22. Which type of microbes causes amoebiasis?
Answer:

Some protozoal microbes are responsible.

Question 23. How tuberculosis can spread from one person to other?
Answer:

It can spread through cough and sneezing.

Question 24. Which symbiotic bacteria are found in root nodules of leguminous plants?
Answer:

Rhizobium lives in root nodules.

Question 25. Which symbiotic bacteria live in the human intestine?
Answer:

The symbiotic bacteria Escherichia coli live in the human intestine.

Question 26. Which microbial association is found in Lichen?
Answer:

In lichen, an association of algae and fungi is found.

Question 27. What is the term used to denote the mutually beneficial association between two organisms?
Answer:

The term is symbiosis.

Question 28. How the bacteria Azotobacter is helpful?
Answer:

It helps to fix nitrogen in the soil.

WBBSE Class 8 Science Important Very Short Answers

Question 29. What is the function of nitrifying bacteria?
Answer:

It converts ammonia into nitrate and nitrite.

Question 30. Which bacteria help in the formation of curd from milk?
Answer:

The bacteria is Lactobacillus.

Question 31. What is the term used for the process of food preservation in air-tight containers?
Answer:

It is known as canning.

Question 32. By which process, milk can be preserved?
Answer:

It is done by Pasteurization.

Question 33. what are antibiotics?
Answer:

Antibiotics:

These are life-saving drugs produced from microbes.

Question 34. Who first discovered antibiotics?
Answer:

Alexander Flemming first discovered antibiotics in the year 1928.

Question 35. What are antigens?
Answer:

Antigens:

Antigens are foreign substances that may enter our body fluid.

Very Short Answer Questions for Class 8 Microbial World

Question 36. What are antibodies?
Answer:

Antibodies:

Antibodies are protein substances produced by our body’s defense mechanism to fight against antigens.

Question 37. What is vaccination?
Answer:

Vaccination:

Vaccination is the administration of antigenic material (a vaccine) to stimulate an individual’s immune system to develop immunity against a pathogen.

Question 38. Name two diseases that can be controlled, by vaccination.
Answer:

Typhoid, tetanus, polio, diphtheria, smallpox, tuberculosis, etc (any two are to be .. mentioned).

Question 39. Which gas may be produced from the treatment of wastes?
Answer:

Methane gas may be produced.

Question 40. Name algae that is used in space shuttles.
Answer:

Chlorella is used to clean the enclosed air.

Question 41. Name some methods of food preservation.
Answer:

Pasteurization, Pickling, Freezing, etc.

WBBSE Class 8 Science Study Guide Microbial World

Question 42. What are biofertilizers?
Answer:

Biofertilizers:

Biofertilizers are the microbes that can bring about the nutrient enrichment of soil and enhances the nutrient availability to crop plants. Example: Azotobacter, Azolla-anabaena, Rhizobium etc.

Question 43. Name two plant pathogenic fungi.
Answer:

Albugo Candida and Puccinia graminis.

Microbial World WBBSE Class 8 Resources

Question 44. Name two algae that are used as food.
Answer:

Alaria and Laminaria.

Question 45. Name a virus that is used as a biopesticide.
Answer:

Nucleopolyhedrosin virus (NPV).

WBBSE Solutions For Class 7 History Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule

WBBSE Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule Long Question And Answers

Question 1. Discuss Akbar’s Rajput Policy. Or, What policy did Emperor Akbar follow against the Rajputs?
Answer:

Akbar’s Rajput Policy:

  • Mughal Emperor Akbar realized that to strengthen the Mughal Empire, it was vital to obtain the support of the Hindus, particularly the Rajputs, a brave and loyal martial race.
  • He tried to bring the Rajputs in his favor by establishing friendly relations with them. He also wished to give an Indian colour to the Mughal policy.

The Rajput policy of Akbar

  • Matrimonial alliance: Akbar followed a policy of diplomacy and matrimonial alliance towards the Rajputs. He married the daughter of Biharimal (Bhara Mal), the king of Amber and gave his son Jahangir in marriage to the daughter of Bhagwan Das. He also married the princesses of Marwar, Bikaner, Bundi, and Ranthambhore and these states accepted his supremacy.
  • Military power: Mewar was not ready to accept Akbar’s overlordship. The Sisodia rulers Rana Udai Singh and his son, Rana Pratap refused to submit before Akbar. Akbar fought against Udai Singh to occupy Mewar in 1567 and the Mughals defeated Rana Pratap in the Battle of Haldighat in 1576. However, he could never curb Rana Pratap.
  • Recruitment in high ranks: To obtain the loyalty and friendship of the Rajputs, Akbar appointed them to high posts in the civil and military departments.
  • Religious tolerance: To befriend the Rajputs, Akbar also abolished the Hindu pilgrim tax and jizya and participated in Hindu festivals like Holi, Diwali, and others. Thus, the Rajputs became powerful allies of the Mughals and became the strongest and most loyal pillar of support for the Mughal empire.

Read and Learn More WBBSE Solutions For Class 7 History

Question 2. Discuss Aurangzeb’s Rajput Policy.
Answer:

Mughal Emperor Aurangzeb adopted an illiberal policy towards the Rajputs. He was never inclined to maintain a friendly relationship with Rajputs. Sir Jadunath Sircar has termed Aurangzeb’s Rajput policy as an ‘extreme political ignorance’.

The Rajput Policy of Aurangzeb Political Activities:

  • Control over Marwar: Aurangzeb was narrow-minded and reversed the policy of friendship towards the Rajputs, unlike his predecessors. After the death of Yashwant Singh, he tried to occupy Marwar.
  • Mewar invasion: He attacked Mewar. but later on concluded peace with both Mewar and Marwar, due to the spirited resistance of the Rajputs. He was foolish enough to interfere in the internal feuds of the Rajputs as it escalated into a full-fledged Mughal- Rajput contest.

Results:

  • Aurangzeb was a bigot, blinded by his orthodoxy. He failed to realize that the Rajputs were invaluable for the Mughals. They were the major strength against the Pathans in the north-western frontiers and the Marathas in the Deccan.
  • Aurangzeb’s Rajput policy proved to be very harmful. The loss of Rajput support spelled doom for the Mughals. Aurangzeb brought about the decline of the Mughal empire due to his imprudence.

 

WBBSE Solutions For Class 7 History Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule

Question 3. Write a note on the Mansabdari System.
Answer:

Mughal Emperor Akbar introduced the Mansabdari System in India in 1577, on the Persian model of Central Asia.

Mansabdari System

  1. Meaning: The word Mansab meant rank or position, and one who occupied this rank was called Mansabdar.
  2. Salary: Mansabdars received salaries either in cash or in the form of jagirs, in lieu of cash. They had to keep a fixed number of horses and horsemen, whom they maintained spending the revenue earned from the Jagir.
  3. Ranks: There were thirty-three ranks of Mansabdars, with the lowest being 10 and the highest being 10,000. This number signified the number of horses and horsemen under the Mansabdar.

Features:

  1. The system was not hereditary. Mansabdars were appointed, transferred, promoted, and demoted according to the will of the emperor.
  2. Mansabdars were transferred from one Jagir to another after a certain period of time. After the death of Mansabdar, his entire property came under the Emperor’s control. Mansabdars were sometimes granted pompous titles like Khan-i-Khanan and Khan-i-Jahan.

Question 4. Write a note on Jagirdari System in the Mughal Empire.
Answer:

Jagir was a piece of land allotted to a particular person by the State for the realization of land revenue. The donee of Jagir was termed Jagirdar.

Jagirdari System

1. Types:

There were various forms of Jagir in the Mughal polity.

  1. Tankha Jagirs: These were bestowed on those who received Jagirs from the ruler in lieu of cash salaries.
  2. Watan Jagirs: These were occupied by Zamindars as hereditary rights.
  3. Mashrut Jagirs: These were bestowed on specific persons in lieu of particular posts.
  4. Inam Jagirs: These were bestowed as rewards to accomplished or pious men.

2. Crisis:

A crisis overtook the Jagirdari system from the reign of Aurangzeb itself.

  1. The Jagirdars were engaged in a mutual rivalry with each other for the most fertile jagirs of North India which yielded high revenue, as none wanted to be posted in the politically turbulent Deccan. This gave rise to jealousy and conspiracy among different parties and groups in the royal court.
  2. There was a wide gulf between Jama (the assessed revenue) and Haasil (the actual revenue collected) from farmers. This fuelled corruption. So, the Jagirdari system reached a critical situation.
WBBSE Class 7 Geography Notes WBBSE Solutions For Class 7 History
WBBSE Solutions For Class 7 Geography WBBSE Class 7 History Multiple Choice Questions
WBBSE Class 7 Geography Multiple Choice Questions WBBSE Solutions For Class 7 Maths

 

Question 5. Write what you know about the status of Zamindars in the Mughal era.
Answer:

Zamindars were those individuals who enjoyed ownership of land in lieu of certain terms and conditions.

Zamindars in the Mughal era

Different names: The term Zamindar had various synonyms in various parts of the country. He was called Satarohi and Vishwi in Ayodhya and Bhoomi in Rajasthan.

Classification:

In the Mughal era, there were three levels of Zamindars

  • Samanta:
    • These Zamindars were independent and sovereign in their own estates. Their lands were measured and the revenue was assessed accordingly.
    • The Mughal emperors included them in to the administrative system by bestowing jagirs and man says. Middle-ranked or intermediate
  • Zamindars:
    • They had no specific ownership of land but were in charge of revenue collection and maintenance of law and order.
    • They were called Chaudhury, Deshmukh, Muqaddam, Mukhia, and Kanungo.
  • Primary Zamindars:
    • They were posted under middle-ranking zamindars. They were hereditary owners of land and had the right to sell land and transfer ownership.
    • Villages or lands were measured and the revenue was assessed thereafter.

Question 6. Describe the structure and nature of the Mughal nobility.
Answer:

Structure of Mughal nobility During the Mughal era Zamindars, Jagirdars, and Mansabdars together formed the nobility or aristocracy.

  1. Mansabdars: They consisted of three racial groups-Iranis, Turanis, and Hindustanis.
  2. Jagirdars: They were of four categories based upon four types of Jagirs-Tankha, Watan, Mashrut, and Inam.
  3. Zamindars: They were divided into three types-Samanta, middle-rank intermediate Zamindars, and primary Zamindars.

Nature of Mughal Polity

  • The Mughal royalty and nobility were more or less synonymous. The nobles occupied high ranks in the administrative spheres. They performed civil and military duties and responsibilities in return for handsome salaries.
  • The aristocracy was not always hereditary but had specific groups like Irani, Turani, Rajput, Afghan, Sheikhzada, and minority classes of Indian Muslims.

Understanding Mughal Relations with Rajputs

Question 7. Describe the nature of the Mughal polity. Or, State the administrative ideals of the Mughal Empire.
Answer:

The Mughal Empire was set up by Babur in 1526 on the ruins of the Delhi Sultanate.

Nature of Mughal Polity

1. Benevolent despotism:

  • The Mughal rulers emphasized on the welfare of the subjects. The ruler was absolute but a benevolent despot.
  • He was at the same time the commander-in-chief, the highest judge in the court of appeal, and the main legislator. Akbar’s ideals were followed by Jahangir and Shah Jahan.

2. Military character:

  • The Mughal State was basically a military State. Apart from the Sadar and Qazi, all other Mughal employees performed military responsibilities.
  • Prof. Tapan Roychoudhuri and other historians felt, that the Mughal State was founded on military strength.

3. Secularism:

  • The Mughal empire followed a policy of universal tolerance. All the rulers, except Aurangzeb, followed this policy and retained the secular character of the State.
  • The Mughal emperors believed in divine right.
  • Yet, they treated people of all castes and creeds equally. This secular character was specifically reflected in the policies of Akbar.

4. Blend of communal diversity:

  • The Mughal nobility possessed a diverse character, comprising of Iranis, Turanis, Mongols, Indian Muslims (Hindustanis) and Hindus.
  • This enriched the Mughal administration.

Question 8. Describe the Zabti System.
Answer:

Zabti System:

  • Todarmal, the revenue Minister of the Mughal emperor Akbar, made the Dahsala system more logical and streamlined. The modified revenue system was called the Zabti System.
  • He decided that one-third of the average agricultural output should be given up as land revenue, either in cash or in kind.

Zabti System

1. Major divisions:

The land was measured both in terms of the fertility of soil and rate of agricultural production and then divided into four parts-

  1. Polaj: Land that was cultivated throughout the year and never left fallow.
  2. Parauti: Land which was sometimes left fallow to recover fertility.
  3. Chachar: Land that was cultivated every four years.
  4. Banjar: Land which was left out of cultivation for five years or more.

2. Subdivisions:

  • The Polaj and the Parauti lands were divided into three categories- excellent, mediocre and poor, based on the volume of average agricultural output.
  • The total produce of ten years was determined, the average was obtained and one-third of this average was fixed as revenue.

3. Evaluation:

  • The State acquired the entire share of the revenue without any intermediary collector and the peasants or ryots were also aware of the amount of revenue they had to pay to the State.
  • The ryots received the Patta document from the State, highlighting their rights on land and so, they could not be evicted easily. This system was not followed all over India, so all peasants were not benefited by this.

Question 9. Compare between the Rajput policy of Akbar and that of Aurangzeb.
Answer:

During the reign of Akbar the Rajputs were loyal supporters and the bulwark of the Mughal empire. But the unwise policy of Aurangzeb had pushed them to the path of rebellion.

Comparison between the Rajput policy of Akbar and Aurangzeb

  1. Rajput policy of Akbar: He understood the value of the Rajput alliance in building an empire in India. He followed the policy of reconciliation with the Rajputs in order to secure their cooperation.
  2.  Rajput policy of Aurangzeb: The Rajput policies adopted by Aurangzeb were strict and stern. All the Rajput rulers were at peace with the Mughals when Aurangzeb ascended the throne. But Aurangzeb reversed the policy. He never kept faith in their loyalty.
  3.  Factors responsible for Aurangzeb’s conflict with the Rajputs:
    • Aurangzeb was an expansionist.
    • He was a bigot.
    • Conflict with Marwar.
    • Conflict with Bundelkhand.

Results:

Because of Akbar’s liberal policy, the valiant Rajputs joined hands with the Mughals. Aurangzeb’s Rajput policy proved very disastrous for the Mughals and deprived Aurangzeb of the loyalty of the brave Rajputs.

Conceptual Questions on Cultural Exchange Between Mughals and Rajputs

Question 10. What was the Deccan policy of Aurangzeb? What was its result?
Answer:

Deccan policy of Aurangzeb Aurangzeb’s Deccan policy refers to the extended period of conflict and diplomacy between the Mughals and the states of Bijapur, Golconda, and the Marathas under Shivaji and his successors.

Results

  1. Annexation of Bijapur and Golconda was a blunder on the part of Aurangzeb as it destroyed the check on the Marathas.
  2. With the annexation of Bijapur and Golconda the Mughal empire became too large to be ruled by one man or from one center.
  3. Long warfare caused serious damage to the Muhgal economy. It exhausted the royal treasury. It gave rise to the rebellion in the army. They were deprived of their salary.
  4. The emperor’s absence from the capital for long 26 years was damaging for the empire. He lost control over the officers of the north. Conclusion: According to historians, “The Deccan was the grave of his reputation as well as of his body.”

Question 11. Describe the Mughal administrative system from Babur to Akbar.
Answer:

Mughal administrative system from Babur to Akbar

1. Babur:

  • Babur ruled in India for four years. Within this short period, he disposed of three formidable rivals and founded a royal house on a solid footing.
  • As he was engaged in a war for the greater part of this period, he could not undertake any administrative reforms. There were no significant administrative changes in the time of Humayun also, due to political instability.

2. Influence of Sher Shah:

  • Apart from being a great warrior, Sher Shah was also an able administrator and leader. Moreover, Sher Shah largely influenced the administrative system of Akbar.
  • Therefore, it is true that Akbar was not an innovator but he had the talent to build up an efficient system of administration on the basis of a happy combination of foreign and indigenous elements.

Class 7 WBBSE History Question Answer

3. Akbar and the Mansabdari System:

  • Towards the end of Akbar’s reign, his empire was divided into 15 provinces (subahs), which were subdivided into Sarkar and Parganas.
  • The Mansabdari system which was introduced by Akbar was the basis of the civil and military administration of the country. The word ‘mansab’ literally means ‘rank’ or status in imperial service. The holder of ‘mansab’ was called ‘mansabdars’.

4. Appointment of the Rajputs:

As the Rajputs were efficient in battle and warfare, they were of offered ‘mansabs’ by Akbar. Their military skill was appreciated by him.

Conclusion:

Later, due to its inherent weakness, the system was abolished during the rule of Aurangzeb.

Question 12. Describe the administrative principles of the Mughals.
Answer:

The Mughal rule of over two hundred years constitutes an important chapter in the history of India. The Mughals made valuable contributions in different spheres of Indian life.

Administrative principles of the Mughals

  1. Political Unity: In ancient India, there was no political or administrative unity among them. But in Mughal India, there was a uniform system of administration all over the empire.
  2. Administrative Principles of Akbar:
    1. Akbar was the real founder of the administrative system of the Mughals. According to the historians, the Mughal system of administration was not original.
    2. The Mughal system of administration was therefore a mixture of Indian and foreign elements. Akbar did not ignore anything-Indian tradition, village autonomy-all found their rightful place in the administrative system.
    3. This system was broad-based upon the willing support of the people.
  3. Din-i Ilahi: The principle of mutual faith and understanding was known as Sulh-i kul. Din-i Ilahi was the outcome of this principle.

Real-Life Scenarios Involving Conflicts with Rajputs

WBBSE Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule Short Question And Answers

Question 1. What was the relationship of Akbar with the Rajputs?
Answer:

The relationship of Akbar with the Rajputs:

  • Akbar was a true statesman. He understood the value of the Rajput alliance in building an empire in India. He followed a policy of conquest and reconciliation with the Rajputs in order to secure their cooperation.
  • Akbar entered into matrimonial alliance with some royal families. He abolished the pilgrimage tax and the Jizya from the Hindus only to foster relations between them.

Question 2. What were the effects of Akbar’s Rajput Policy?
Answer:

The effects of Akbar’s Rajput Policy:

  • The Mughal policy towards the Rajputs contributed to the expansion and consolidation of the Mughal Empire. In fact, the policy was largely designed to serve the political needs for the empire.
  • The Rajput policy of Akbar effectively ended the centuries-old animosity between the two since the Rajputs were assimilated in the administrative structure of the empire.
  • It affected the public policies of Akbar and helped in the development of a composite culture.

Question 3. How far the ‘Deccan Ulcer’ of Aurangzeb responsible for the downfall of the Mughal empire?
Answer:

‘Deccan Ulcer’ of Aurangzeb was responsible for the downfall of the Mughal empire:

  • The failure of Aurangzeb in the Deccan wars destroyed the military strength and prestige of the Mughals. Too much of expenditure made the Mughal Government bankrupt.
  • Moreover, with the annexation of Bijapur and Golconda, the Mughal empire became too large to be ruled. The emperor’s absence from the capital for long 25 years was damaging for the empire.
  • Thus the Deccan wars can be called the ulcer that destroyed the Mughal empire. The inherent administrative chaos of the empire played a vital role in the decline of the Mughal empire.

Question 4. What was Sulh-i Kul? What were its effects?
Answer:

Sulh-i Kul:

  • The theory of divine right was very much linked with the concept of Akbar’s paternal government. One of the necessary virtues of this type of government was the promotion of ‘peace with all’.
  • Sulh-i Kul which implied religious toleration. The outcome of Sulh-i Kul was Din-i Ilahi which was introduced by Akbar in 1582.

Effects:

  • By Sulh-i Kul, Akbar, as a national monarch, wanted to establish a national religion. Sulh-i kul as well as Din-i Ilahi was an experiment in that direction.
  • This principle provided a common platform for all the people, where they can unite for God and the king. It must have strengthened the hands of Akbar and his administration.

Class 7 WBBSE History Question Answer

Question 5. Write about the Suba’s administration.
Answer:

Suba’s administration:

  • The Mughal Empire was divided into fifteen provinces or the Subas. The governors of the Subas or the Subadars were in charge of the provinces. The provinces were divided into districts or ‘Sarkars’.
  • Sarkars were further subdivided into Parganas. A pargana had numerous villages under it. There were administrative blocks in every suba.

Question 6. Write a note on Akbar’s revenue system.
Answer:

Akbar’s revenue system:

  • Raja Todarmal, as finance minister of Akbar, introduced a new system of revenue known as ‘Zabti’ and a system of taxation called ‘Dahshala’ or a ten-years settlement.
  • He took a careful survey of crop yields and prices cultivated for a period of ten years (1570 to 1580). On this basis, the tax was fixed on crops in cash.
  • Farmers could get loans easily from the state which could be repaid in installments. In bad seasons, remission of revenues were granted to the farmers.

Examples of Real-Life Applications of Historical Knowledge

Question 7. How was Akbar influenced by Humayun to adopt the policy of the Rajput alliance?
Answer:

  • The Mughal emperor Humayun became fully aware of the fact that the Rajputs were the most powerful landlords of northern India.
  • So to seize the power of Hindustan, it was important for the Mughals to maintain a cordial relationship with the Rajputs. Later, Akbar himself revised the Rajput policy and absorbed the Rajputs in the mansabdari system.

Question 8. Give examples of Akbar’s liberal Rajput policy.
Answer:

Akbar’s liberal Rajput policies were

  1.  Akbar gave complete religious freedom to his Hindu wives and gave an honored place to their parents and relations in the nobility and he gave high posts to Rajputs in his empire.
  2. He married Rajput princesses to strengthen his ties with the Rajputs.
  3. He also abolished sectarian taxes on non-Muslims.

Question 9. “From Akbar to Aurangzeb, there were much similarities in the Mughal Rajput policy.”-What are they? What are they
Answer:

  • In pursuance of his policy towards the Rajputs, Akbar absorbed them into the mansabdari system. Jahangir and Shah Jahan too followed the same policy.
  • Later, at the time of Aurangzeb, the Rajputs were brought within the fold of Mansabdari system. They were also given high posts in the royal court.

Important Definitions Related to Mughal Policies

Question 10. What were the factors that contributed to the Deccan policy of Aurangzeb?
Answer:

Aurangzeb’s policy towards the Deccan had political as well as economic purposes.

  1. The extension of the empire was one purpose of Aurangzeb.
  2. Aurangzeb was tempted to conquer them with a view to possessing their wealth. He also wanted to realize much more revenues from the states.

Therefore, Aurangzeb was not satisfied simply by the acceptance of his suzerainty by them but he desired to annex them to the Mughal empire.

Question 11. Who introduced Din-i Ilahi? What was its main principle?
Answer:

  1. Din-i llahi, a monotheistic religion was put into effect by Akbar in 1582 AD.
  2. The main principle of this religion was ‘Sulh- i kul’, which means ‘peace with all’, ‘universal peace’, ‘absolute peace’, etc.

Question 12. What were the main features of the Mansabdari system?
Answer:

The main features of the Mansabdari system were

  1. The emperor himself appointed or dismissed the mansabdars. He was always the last word.
  2. The system was not hereditary.
  3. They were often offered titles like ‘Khan-i- Khanan’, ‘Khan-i-Jahan’ etc.

Question 13. How the mansabdars were paid?
Answer:

Mansabdars were paid his salary in cash. All the ‘mansabdars’ were paid through an assignment of ‘jagir’ which bore the cost of their maintenance. Their horsemen were also looked after in this way.

Short Answers on Deccan Policy of the Mughals

WBBSE Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule Very Short Question And Answers

Question 1. Where was Asirgarh?
Answer: It was in Khandesh.

Question 2. Who introduced Din-i Ilahi?
Answer: Akbar introduced Din-i Ilahi.

Question 3. Who was in charge of ‘mansabs’?
Answer: Mansabdars were in charge of ‘mansabs’.

Question 4. Who was the finance minister of Akbar?
Answer: Todarmal was the finance minister of Akbar.

Question 5. Who reintroduced Jizya?
Answer: Aurangzeb reintroduced Jizya.

Question 6. Who was Jagirdar?
Answer: The holder of ‘Jagir’ was called Jagirdars.

Question 7. How many Subas were there in the Mughal Empire?
Answer: There were 15 subs in the Mughal Empire.

Question 8. What was the other name of the Dahsala settlement?
Answer: The other name of Dahsala Settlement was Todarmal Settlement.

Question 9. Who introduced the mansabdari system?
Answer: Akbar introduced the mansabdari system.

Question 10. Name the two states of the Deccan which were conquered by the Mughals.
Answer: Aurangzeb aimed to destroy the Maratha powers under Shivaji and annex Golconda and Bijapur to fetch more money from there.

Question 11. What was the ‘Dahsala’ system?
Answer:

‘Dahsala’ system: Dahsala system was a system of taxation. ‘Daha’ means ‘ten’. Under the system, Todarmal took a careful survey of crop yields and prices cultivated for a period of 10 years.

WBBSE Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule Fill In The Blanks

Question 1. The word ‘watan’ means_____________ (native land/national flag/foreign).
Answer: Native land

Question 2.(Amar Singh/Pratap Singh/Man Singh)______________, son of Rana Pratap was awarded a high mansab.
Answer: Amar Singh

Question 3. The name of the important fort of Khandesh was______________ (Asirgarh/Bidar/Chittor).
Answer: Asirgarh

Question 4. Aurangzeb spent______________  (20/22/25) years in Deccan.
Answer: 25

Question 5. Aurangzeb had to accept the Maratha leader ______________ (Shivaji/Shambhuji/Nana Saheb) as an independent King.
Answer: Shivaji

Question 6. Akbar’s principle of mutual respect and peace with all is known as ______________ (Sulh-iKul/Din-i Ilahi/mansabdari).
Answer: Sulh-iKul

Question 7. The ‘provinces’ were called ______________ (Suba/Sarkar/Pargana).
Answer: Suba

Question 8. The meaning of the word ‘mansab’ is______________  (title/rank/land).
Answer: Rank

Question 9. The high-ranking mansabdars were called______________  (Karori/Amir/Shah).
Answer: Amir

WBBSE Chapter 5 The Mughal Empire Topic B The Nature Of Rajput And The Deccan Policy Of The Mughals Imperial Rule True Or False

Question 1. Aurangzeb imposed Jizya on the Hindus.
Answer: True

Question 2. A Deccan ulcer was created by Shah Jahan.
Answer: False

Question 3. Sulh-i Kul was introduced by Aurangzeb.
Answer: False

History Class 7 WBBSE

Question 4. The mansabdar system was hereditary.
Answer: False

Question 5. ‘Daha’ means ‘ten’.
Answer: True

Question 6. The word ‘mansab’ means rank.
Answer: True

Question 7. Provinces of the Mughal empire were ‘Suba’.
Answer: True

Question 8. The Dahsala system was introduced by Jahangir.
Answer: False

Question 9. ‘Watan’ means foreign land.
Answer: False

Question 10. Din-i Ilahi was promulgated in 1582 AD.
Answer: True

WBBSE Solutions For Class 8 School Science Chapter 7 The Microbial World Review Questions

Chapter 7 The Microbial World Review Questions MCQs

Question 1. Microbes are

  1. Living
  2. Non-living
  3. Inorganic compounds
  4. None of these

Answer: 1. Living

Question 2. Microbes are visible by

  1. Naked eye
  2. Microscope
  3. Hand lens
  4. Spectacle

Answer: 2. Microscope

Question 3. Bacteria, viruses, and protozoa are

  1. Animals
  2. Plants
  3. Microbes
  4. Carriers

Answer: 3. Microbes

Question 4. The application of microbial metabolism to transform simple raw materials into valuable products is called

  1. Biocatalysis
  2. Tissue culture
  3. Genetic engineering
  4. Fermentation

Answer: 4. Fermentation

WBBSE Solutions For Class 8 School Science Chapter 7 The Microbial World Review Questions

Question 5. An ideal place of survival of microbes

  1. Damp places
  2. Sunny places
  3. Dry places
  4. Rocky surfaces

Answer: 1. Damp places

Read And Learn More WBBSE Solutions For Class 8 School Science Review Questions

Question 6. The microbes that can produce their own food

  1. Protozoa
  2. Virus
  3. Algae
  4. Bacteria

Answer: 3. Algae

Question 7. Microbes prefer the temperature for growth

  1. 0°C-5°c
  2. 25°C-35°c
  3. 100°C-110°c
  4. Sub-zero temperature

Answer: 2. 25°C-35°c

Question 8. For microscope observation, specimens are generally

  1. Moist
  2. Heated
  3. Stained
  4. Acidified

Answer: 3. Stained

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 9. Which one is not a microbe?

  1. Bacteria
  2. Fungus
  3. Small plants
  4. Virus

Answer: 3. Small plants

Question 10. Microbes may be

  1. Beneficial or harmful
  2. Always Harmful
  3. Always Beneficial
  4. All of these

Answer: 1. Beneficial or harmful

Question 11. Curd, milk, cheese, and butter are produced with the help of

  1. Yeast
  2. Acetobacter
  3. Penicillium
  4. Streptococcus

Answer: 4. Streptococcus

Question 12. Antibiotics are mostly produced commercially from

  1. Viruses
  2. Saprophytic bacteria
  3. Parasitic host
  4. All of these

Answer: 2. Saprophytic bacteria

Question 13. Louis Pasteur is famous for the discovery of

  1. Bacteria
  2. Life
  3. Vaccine of hydrophobia
  4. Antigen

Answer: 3. Vaccine for hydrophobia

Chapter 7 The Microbial World WBBSE Solutions

Question 14. Bacteria are placed under the kingdom

  1. Plantae
  2. Monera
  3. Protista
  4. Akaryota

Answer: 2. Monera

Question 15. Pseudopodia is the locomotory structure of

  1. Bacteria
  2. Algae
  3. Protozoa
  4. Virus

Answer: 3. Protozoa

Question 16. Hyphae is a term associated with

  1. Fungi
  2. Algae
  3. Microbes
  4. Virus

Answer: 1. Fungi

Question 17. Penicillium is a

  1. Fungus
  2. Algae
  3. Medicine
  4. Fertilizer

Answer: 1. Fungus

WBBSE Class 8 Science Important Review Questions

Question 18. An example of colonial algae is

  1. Chlamydomonas
  2. Volvox
  3. Spirogyra
  4. Mucor

Answer: 2. Volvox

Question 19. Biofertilizers include

  1. Cyanobacteria
  2. Mycorrhizal fungi
  3. Nitrifying bacteria
  4. All of these

Answer: 4. All of these

Question 20. Virus can be seen under

  1. Electron microscope
  2. Simple light microscope
  3. Compound light microscope
  4. None of these

Answer: 1. Electron microscope

Question 21. The nucleic acid of the virus is

  1. Both DNA and RNA
  2. Either DNA or RNA
  3. Only rna
  4. Only DNA

Answer: 2. Either DNA or RNA

Review Questions for Class 8 Microbial World

Question 22. Viruses are

  1. Unicellular
  2. Multicellular
  3. Acellular
  4. Prokaryotes

Answer: 3. Acellular

Question 23. The word ‘virus’ in Latin means

  1. Poison
  2. Sweet
  3. Dangerous
  4. Friend

Answer: 1. Poison

Question 24. Which is not a bacterial disease?

  1. Tuberculosis
  2. Tetanus
  3. Cholera
  4. Aids

Answer: 4. Aids

Question 25. Which is a protozoan disease?

  1. Polio
  2. Malaria
  3. Ringworm
  4. Polio

Answer: 2. Malaria

Microbial World WBBSE Study Guide

Question 26. Diarrhea is transmissible through

  1. Air
  2. Carrier
  3. Water
  4. Food

Answer: 3. Water

Question 27. Amoebiasis is caused by a

  1. Protozoa
  2. Virus
  3. Fungus
  4. Algae

Answer: 1. Protozoa

Question 28. Rhizobium is a

  1. Parasite
  2. Symbiont
  3. Free-living
  4. Host

Answer: 2. Symbiont

Question 29. In humans, e. Coli supplies

  1. Vitamin b12
  2. Vitamin c
  3. Nitrogen
  4. Protein

Answer: 1. Vitamin b12

Chapter 7 Microbial World WBBSE Resources

Question 30. Which of the following is not a communicable disease?

  1. Cancer
  2. Cholera
  3. Chickenpox
  4. Malaria

Answer: 1. Cancer

Question 31. Saprophytes draw nourishment from

  1. Living organism
  2. Parasites
  3. Dead organic matter
  4. Metallic substances

Answer: 3. Dead organic matter

Question 32. Which is not a nitrogen-fixing bacteria?

  1. Clostridium
  2. E. Coli
  3. Azotobqcter
  4. Y. Pestis

Answer: 2. E. Coli

Question 33. The breakdown of the nitrogenous compounds to ammonia is

  1. Ammonification
  2. Nitrification
  3. Nitrogen fixation
  4. Denitrification

Answer: 1. Ammonification

Question 34. Curd forming microorganisms is

  1. Lactobacillus
  2. Penicillium
  3. Rhizobium
  4. Metha no-bacteria

Answer: 1. Lactobacillus

Question 35. Which of the following diseases is not caused by bacteria?

  1. Cholera
  2. Typhoid
  3. Measles
  4. Tuberculosis

Answer: 3. Measles

Question 36. Antibiotics may be produced from

  1. Microbes
  2. Animals
  3. Plants
  4. Minerals

Answer: 1. Microbes

Question 37. The microorganisms which can multiply and reproduce only inside the cells of other organisms are

  1. Protozoa
  2. Fungi
  3. Virus
  4. Bacteria

Answer: 3. Virus

Question 38. Antibiotics are not effective against

  1. Bacteria
  2. Fungus
  3. Microbes
  4. Virus

Answer: 4. Virus

Question 39. Which of the following is not an area where microorganisms are employed?

  1. Preparation of drugs
  2. Recycling of materials in nature
  3. Preparation of food by photosynthesis
  4. Increasing the fertility of the soil

Answer: 3. Preparation of food by photosynthesis

Question 40. Proper vaccination can prevent the spread

  1. Bacteria
  2. Virus
  3. Protozoa
  4. Algae

Answer: 2. Virus

Question 42. Refrigeration helps in food

  1. Preservation
  2. Degradation
  3. Nitrification
  4. Preparation

Answer: 1. Preservation

Question 43. A pathogenic protozoan residing in the human digestive tract is

  1. T. Gambiense
  2. P. Ovale
  3. Trichonympha
  4. Giardia intestinalis

Answer: 4. Giardia intestinalis

Question 44. Which among the following vitamin is/are produced using microbes?

  1. Vit b12
  2. Carotene
  3. Riboflavin
  4. All of these

Answer: 4. All of these

Question 45. Which one is a viral disease ?

  1. Mumps
  2. Tetanus
  3. Pneumonia
  4. Ringworm

Answer: 1. Mumps

Chapter 7 The Microbial World Fill in the blanks

 

Question 1. The algae___________is used as food in the space station.
Answer: Chlorella

Question 2. Bread mold is a type of ___________
Answer: Fungus

Question 3. Microbes have survived over ___________ billion years on earth.
Answer: 3.5

Question 4. ___________ microbes can survive in presence of oxygen.
Answer: Aerobic

Question 5. ___________ are the microbes that can produce their own food.
Answer: Algae

Question 6. The process of coloring specimens for microscopic observation is known as ___________.
Answer: Staining

Question 7. An example of the kingdom Protista is ___________.
Answer: Protozoa

Question 8. Bacterial nucleus is known as___________ .
Answer: Nucleoid

Question 9. Membrane-bound cell organelle is absent in ___________.
Answer: Bacteria

Question 10. In 1674,___________ proved the existence of bacteria.
Answer: Leeuwenhock

Question 11. Bacteria are placed under the kingdom ___________
Answer: Monera

Question 12. Pseudopodia is the locomotory organ of some ___________.
Answer: protozoa

Question 13. Yeast is a unicellular ___________.
Answer: Fungus

Question 14. In fungus, a large number of ___________ together form mycelium.
Answer: Hyphae

Question 15. Fungi can not synthesize their food due to lack of ___________.
Answer: Chloroplast

WBBSE Class 8 Science Practice Questions on Microbes

Question 16. Spirogyra is a ___________ filamentous algae.
Answer: Multicellular

Question 17. Algae are ___________ in color.
Answer: Green

Question 18. Hydrophobia is a ___________ disease.
Answer: Viral

Question 19. Mushroom is a ___________.
Answer: Fungus

Question 20. Parasites live in association with ___________.
Answer: Host

Question 21. Vitamin deficiency may be caused by the death of beneficial ___________ within our intestine.
Answer: Bacteria

Question 22. Rhizobium lives in the root nodules of ___________ plants.
Answer: Leguminous

Question 23. Lichen has an association of ___________ and fungus.
Answer: algae

Question 24. In the case of symbiosis both organisms of an association are mutual ___________.
Answer: Benefited

Question 25. The process of surviving on decomposed organic wastes is known as ___________.
Answer: Saprophytes

Question 26. Clostridium is a ___________ fixing bacteria.
Answer: Nitrogen

Question 27. Alcohol is produced from sugar by the fungus ___________
Answer: Yeast

Question 28. Pasteurization is performed to preserve ___________.
Answer: Milk

Question 29. The antibiotic is produced from the fungus ___________ Penicillium.
Answer: Penicillin

Question 30. The natural form of resistance against infection is called ___________.
Answer: Immunity

Chapter 7 The Microbial World Identify As ‘True’ Or ‘False’

Question 1. is not seen by the naked eye.
Answer: True

Question 2. Microbes have most above.
Answer: False

Question 3. The aerobic microbe can survive in absence of oxygen.
Answer: False

Question 4. Bacteria belong to the kingdom Protista.
Answer: False

Question 5. Some microbes can produce their own food.
Answer: True

Question 6. Staining is required for the microscopic observation of specimens.
Answer: False

Question 7. Bacteria, fungi, and plants are microbes.
Answer: False

Question 8. All microbes are harmful.
Answer: False

Question 9. Plastid is absent in bacteria.
Answer: False

Question 10. Rotest Koch discovered the pathogens of malaria.
Answer: False

Question 11. A few protozoa are multicellular.
Answer: False

Question 12. All protozoa possess cilia or flagella
Answer: False

Question 13. Fungi can grow either in the presence or absence of sunlight.
Answer: True

Question 14. Spirogyra is unicellular algae.
Answer: False

Question 15. viruses are acellular.
Answer: True

Question 16. Sibiu. lost’s body viruses behave as inert particles.
Answer: True

Question 17. Influenza and mumps are viral diseases.
Answer: True

Question 18. Ringworm is an animal.
Answer: False

Question 19. AIDS may be transmitted by coughing and sneezing.
Answer: False

Question 20. Rhizobium is a symbiotic protozoan.
Answer: False

Question 21. Lichen is a parasite.
Answer: False

Question 22. Plants can not take atmospheric nitrogen directly from the air.
Answer: False

Question 23. Soyabean is a leguminous plant.
Answer: True

Question 24. Bacteria can convert vinegar to alcohol.
Answer: False

Question 25. The vaccine is an antibiotic drug.
Answer: False

Question 26. Microbes may be used in the treatment of waste materials.
Answer: True

Chapter 7 The Microbial World Match The Column

1. 

Column – A Column – B
A. Bacteria 1. Fungi
B. Protozoa 2. Plantae
C. Fungus 3. Monera
D. Algae 4. Protista

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

2.

 Column – A Column – B
A. Bacteria 1. living or non-living
B. Virus 2. mycelium or hyphae
C. Fungi 3. pseudopodia or cilia
D. Protozoa 4. cell wall and nucleoid

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

3. 

Column – A Column – B
A. Malaria 1. Through food
B. Tuberculosis 2. Through vector
C. Amoebiasis 3. Through blood
D. Hepatitis 4. Through cough

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

4.

Column – A Column – B
A. Plasmodium 1. Saprophyte
B. Lichen 2. Parasite
C. Clostridium 3. Free-living
D. Mucor 4. Symbiotic

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

5.

Column – A Column – B
A. Barber’s itch 1. Bacteria
B. Diarrhoea 2. Virus
C. Encephalitis 3. Fungi
D. Leprosy 4. Protozoans

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

6.

Column =- A Column- B
A. Through drinking water 1. AIDS
B.Through vector 2. Amoebiosis
C. Through blood 3. Kalazar
D. Through air 4. Tuberculosis

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

WBBSE Notes For Class 8 School Science Chapter 7 The Microbial World

Chapter 7 The Microbial World

What are Microbes?

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.

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

Microbial Characteristics

Many characteristic features are used in classifying and identifying microorganisms. In general, these characteristic features have been divided into several major categories.

Read And Learn More WBBSE Notes For Class 8 School Science

1. Classical Characteristics

The classical type of approach such as morphological, physiological, biochemical, ecological, and genetic characteristics has been widely employed to study microbial taxonomy and it also provides phylogenetic information about microorganisms.

2. Morphological characteristics

Morphological features are important in microbial taxonomy for many reasons. Morphology is easy to study and analyze both eukaryotic and prokaryotic microorganisms.

Many different morphological features are used in the classification and identification of microorganisms. Some of these features are cell size, cell shape, colonial morphology, ultrastructural characteristics, staining behavior, cilia, and flagella, mechanism of motility, color, etc.

3. Physiological and Metabolic characteristics

Physiological and metabolic characteristics are very useful because they are directly related to the nature and activity of microbial enzymes and transport proteins.

Because proteins are gene products, analysis of these characteristics provides an indirect comparison of microbial genomes.

4. Ecological characteristics

Microorganisms are well-associated and growing in terrestrial freshwater and marine environments. The taxonomically important ecological properties are life cycle patterns,

The nature of the symbiotic relationships, and the ability to cause disease in particular hosts and habitat preferences such as temperature, pH, oxygen, and osmotic concentration.

WBBSE Notes For Class 8 School Science Chapter 7 The Microbial World

5. Genetic characteristics

Most eukaryotes can reproduce sexually; hence genetic analysis has been of considerable usefulness in the classification of these types of microorganisms.

However, prokaryotes do not reproduce sexually, and chromosomal gene exchange (through transformation and -conjugation) is sometimes useful in the classification of prokaryotes.

The major Characteristics of microbes are

1. Microbes are found almost everywhere, i.e. in deserts, polar regions, saline or brackish water wetlands, and hot streams, and also found in the alimentary canal of humans as well as termites:

2. The majority of microbes require oxygen for survival. However, yeast and tetanus-causing pathogens can survive under low concentrations of oxygen.

3. Damp places are ideal for their growth and survival. Their growth is better in darker places

4. Some of them cannot survive in direct sunlight. Some of them (Saprophytes) collect their food from dead and decaying organic substances.

5. Some of them (Parasites) find shelter in other animals and collect food from different organs or tissues or cells of those animals. Some are able to synthesize their own food (Autotrophs).

WBBSE Class 8 Microbial World notes

6. Generally, the microbes can grow well between 25’Cto 38°C. A few microbes can even grow and survive at- 108C. Some others can grow and survive even above 100°C.

7. The thermophilic (heat-loving) bacteria can grow and reproduce at 100°C. The thermophilic bacteria are found in hot springs and deep-sea hydrothermal vents.

8. Without staining, microbes are invisible to us under the microscope.

Read And Learn More WBBSE Notes For Class 8 School Science

Classification of Microbes

Microbes Are Classified As Follows:

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)

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

Understanding microbes for Class 8

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

WBBSE Chapter 7 summary on microbes

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).

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

Types of microorganisms Class 8

Algae

Algae are found in fresh and saltwater around the world where they can either be free-floating (planktonic) or attached to the bottom.

They can also grow on rocks and trees and in soil when enough water is available. Algae can exist as single cells, an example of which is Chlamydomonas, or joined together in chains like Spirogyra or made up of many cells, for instance, Rhodymenia (red seaweed).

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World Algae

 

All algae contain a pigment called chlorophyll and they make their own food by photosynthesis. Chlorophyll is contained in the chloroplasts and gives many algae their green appearance. Their cell contains a cell wall, nucleus, and other cell organelles.

Fungi

Fungi cannot synthesize their own food as plants do. They have cell walls, nuclei, and other organelles but these do not have chloroplast.

Hence they cannot synthesize food. The cell wall is composed of chitin. Fungi include single-celled living things that exist individually, such as yeast, and multicellular clusters, such as molds or mushrooms.

Yeast cells look round or oval under a microscope. They’re too small to be seen as individuals, but you can see large clusters of them as a white powdery coating on fruits and leaves.

Groups called decomposers to grow in the soil or on dead plant matter where they play an important role in the cycling of carbon and other elements.

Some are parasites of plants causing diseases such as mildews, rusts, scabs, or canker. In crops, fungal diseases can lead to significant monetary loss for the farmer.

A very small number of fungi cause diseases in animals. In humans, these include skin diseases such as athlete’s foot, ringworm, and thrush.

Fungi live in the soil and on your body, in your house and on plants and animals, and in freshwater and seawater. A single teaspoon of topsoil contains about 120,000 fungi. They need moist and warm conditions to grow.

 

WBBSE Solutions For Class 8 School Science Chapter 7 The Mircobial World fungi

Importance of microorganisms in nature for Class 8

Fungi absorb nutrients from living or dead organic matter that they grow on. They absorb simple, easily dissolved nutrients, such as sugars, through their cell walls.

They give off special digestive enzymes to break down complex nutrients into simpler forms that they can absorb. Some fungi are quite useful to us.

We’ve used several kinds to take antibiotics to fight bacterial infections. We use baker’s yeast, to make bread rise and to brew beer.

There are some dangerous fungi that cause diseases in plants, animals, and people. Fungi ruin about a quarter to half of harvested fruits and vegetables each year.

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.

Nutritional Relationships with Other Organisms

Microbes are related to several other organisms to maintain their life and derive nourishment. Some of these relationships are –

1. 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.

2. 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.

3. 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.

Microbial interactions in the environment Class 8

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.

Role of Microbes in the Environment

The human body has( 10-100 trillion microbes living on it, making it one giant super-organism. Since the first link between microbes and diseases was made, people have been advised to wash their hands.

Scientists, however, have recently started to investigate more closely how the microbes that call the human body home affect our health. While some microbes cause disease, others are more beneficial, working with our bodies in many subtle ways.

Microbes and Human Health In fact, many of these microbes are actually beneficial. The microbes living in our digestive system break down food and produce useful vitamins.

The millions of microbes that coat our skin and insides form a protective barrier against more dangerous microbes. Without them, our bodies would be open to microbial attack.

In spite of the benefits, a relatively small number of microbes are harmful to humans. Disease-causing micro organisms are called pathogens.

Many diseases and epidemics are caused by microbes: the plague, smallpox, AIDS, influenza, food poisoning, malaria, and anthrax. These diseases result in severe illness or even death.

Those microbial diseases which spread from an infected person to a healthy person through the air, water, food, physical contact, etc are called communicable diseases.

Some of the communicable diseases are cholera, the common cold, chicken pox, Tuberculosis, etc. As scientists learn more about bacteria, fungi, and viruses, they are better able to treat and prevent these diseases. Common treatments include antibiotics that kill bacteria and vaccines that help the body fight off viruses.

2. Microbes and Ecosystems:

Recycling of waste Microbes obtains energy from their environment. Like humans, many microbes do this by eating plant and animal material.

This is called biodegradation. A typical microbe buffet consists of waste from humans and other animals, dead plants and animals, and food scraps.

Bacteria, fungi, and algae all take part in decomposing—or breaking down—this waste material. Without them, the world would quickly be overrun with discarded food scraps, raw sewage, and dead organisms.

Microbial decomposition releases nutrients into the environment that are needed by other organisms. Microbes are also involved in the cycling of many other important compounds in— and between—ecosystems, including oxygen, carbon, and nitrogen.

Many microbes use the energy of sunlight to convert carbon dioxide to oxygen, which we need to breathe. As they do this, they create new organic material— themselves—which is then eaten by other organisms.

In this way, the cycling of nutrients and energy continues. Microbes like methanogenic bacteria produce biogas, an environment-friendly biofuel.

3. Microbes and Food and Agriculture

People have a long history of using microbes in agriculture and food production. Microbes play a part in the production of food, such as yogurt, cheese, wine, bread, vitamins, beans, and chocolate.

Alcohol is produced by microbes like Yeast. In some cases, microbes function as they would in their original environment. For example, bacteria living around the roots of bean plants (Rhizobium, acetobacter, Clostridium, etc) convert nitrogen from the air into a form that the plant can use, like fertilizer.

People have also learned how to use the natural abilities of microbes to create new food, such as by making beer from grains.

4. Industrial Applications of Microbes

Microbes are so efficient at what they do that scientists use them in many industrial applications. Decomposing microbes are active in wastewater treatment plants, composting facilities, and landfills.

They break down food scraps and waste materials into compost or fertilizer that can be used in gardens or in agriculture. Some industrial facilities capture methane gas that is produced during certain types of decomposition.

The methane can then be used to make ethanol for cars or to generate electricity. Microbes are employed to separate jute fiber from jute stem.

Many types of scientific research involve altering the DNA of microbes or using their DNA to alter other organisms. By changing the DNA sequence of microbes, scientists can use them to create compounds that the microbes would not normally produce.

This includes medical products like Insulin or sources of fuel. Microbes are also used to change the DNA sequence of other organisms, such as changing plants to become resistant to insects or viruses.

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.

Microorganisms and their roles for Class 8 students

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.

Useful and Harmful Microbes

People often use the word germ instead of microbe, so you might think that microbes are all harmful. But some are useful to us.

Useful microbes

  1. Some useful microbes are listed below-
  2. Bacillus thuringiensis – a common soil bacterium that is a natural pest-killer in gardens and on crops.
  3. Arbuscular mycorrhizas – fungus living in the soil that helps crops take up nutrients from the soil.
  4. Saccharomyces cerevisiae – fungus, ba maker’s yeast that makes bread rise.
  5. Escherichia coli-one of many kinds of microbes (bacteria) that live in your digestive system to help you digest your food every day.
  6. Streptomyces – bacteria in soil that makes an antibiotic used to treat infections.
  7. Pseudomonas putida – one of many microbes that clean wastes from sewage water at water treatment plants.

We’ve been using microbes for thousands of years to make products we need and enjoy.

For example, you can thank fungi for the cheese on your cheeseburger and yeast for your bun. Cheese and bread are two microbe-made food people have been enjoying since time began.

In pollution control, researchers are using bacteria that eat methane gas to clean up hazardous waste dumps and landfills.
Fungi and bacteria produce antibiotics such as penicillin and tetracycline.

These are medicines we use to fight off harmful bacteria that cause infections, and other discomforts. Scientists have changed the genetic material of bacteria and yeasts to turn them into medicine.

Harmful microbes

Microbes cause disease when they are able to reproduce in the body. They produce harmful Lactobacillus acidophilus – one of the bacteria that turn milk into yogurt.

There are many other important jobs microbes do. They are used to make medicine. They break down the oil from oil spills. They make up about half of the oxygen we breathe.

They are the foundation of the food chain that feeds all living thin harmful disease-causing microbes in them are infected.

A few harmful microbes, for example, less than 1% of bacteria, can invade our body (the host) and make us ill. Microbes cause infectious diseases There is also strong evidence that microbes may contribute to many non-infectious chronic diseases such as some forms of cancer and coronary heart disease.

Different diseases are caused by different types of microorganisms. Microbes that cause disease are called pathogens.

 

Infectious disease Microbe that causes the disease Type of microbe
Cold Rhinovirus Virus
Chickenpox Varicella zoster Virus
German measles Rubella Virus
Whooping cough Bordetella pertussis Bacterium
Bubonic plague Yersinia pestis Bacterium
TB (Tuberculosis) Mycobacterium tuberculosis Bacterium
Malaria Plasmodium falciparum Protozoan
Ringworm Trichophyton rubrum Fungus
Athletes’ foot Trichophyton mentagrophytes Fungus

 

Uses of microorganisms in daily life for Class 8

To cause an infection, microbes must enter our bodies. The site at which they enter is known as the portal of entry. Microbes can enter the body through the four sites listed below:

  1. Respiratory tract (mouth and nose) e.g. Influenza virus which causes the flu.
  2. Gastrointestinal tract (mouth oral cavity) e.g. Vibrio cholerae which causes cholera.
  3. Urogenital tract e.g. Escherichia coli which causes cystitis.
  4. Breaks in the skin surface e.g. Clostridium tetani which causes tetanus.

It is important to remember that:

  1. A pathogen is a microorganism that has the potential to cause disease.
  2. An infection is the invasion and multiplication of pathogenic microbes in an individual or population.
  3. The disease is when the infection causes damage to the individual’s vital functions or systems.
  4. An infection does not always result in disease.

WBBSE Class 8 School Science Chapter 6 The Structure of Living Organisms SAQs

WBBSE Chapter 6 The Structure Of Living Organisms Short Answer Type Questions

Question 1. What is a microscope?
Answer:

Microscope:

Microscopes are instruments which can both magnify and resolve small objects so that they can be used for observing objects which are not visible to the naked eye. The magnification may range from 15 to 20 times (simple microscope) to 107 times (Electron microscope).

Question 2. What is meant by the magnification of a microscope?
Answer:

Magnification of a microscope:-

Magnification is the power of enlargement or ratio of the size of an object observed under the microscope and its actual size seen with the unaided naked eye.

Question 3. What is meant by resolving the power of a microscope?
Answer:

Resolving the power of a microscope:

The ability to distinguish two close points as distinct clear points are called the resolving power or limit of resolution of a microscope.

WBBSE Class 8 School Science Chapter 6 The Structure of Living Organisms SAQs

WBBSE Class 8 Structure of Living Organisms Short Answer Solutions

Question 4. Write the functions of the cell membrane. Important functions are—
Answer:

Functions of the cell membrane:

  1. Help in cellular compartmentalization.
  2. Bind the semifluid contents of the cell.
  3. Protect the cell from injury.
  4. Act as a semipermeable membrane between a cell and its environment.

Question 5. Write the functions of mitochondria. Important functions are—
Answer:

Functions of mitochondria:

  1. Act as a powerhouse of a cell by forming ATP.
  2. Contain several enzymes.
  3. Transmit some genetic information from one generation to other.

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

Question 6. Name the different types of plastids and state their specific roles in the plant body.
Answer:

Three types of plastids and their roles are—

  1. Chloroplastid—helps photosynthesis.
  2. Chromoplastid—Produce the colour of the flower.
  3. Leucoplastid—Store food materials.

Question 7. Write the common function of RER and SER.
Answer:

Common function of RER and SER:

  1. Provide a large surface area inside a cell for performing biochemical reactions.
  2. Act as a cytoskeletal framework.

Question 8. What is autolysis? State the cell organelle associated with it.
Answer:

Autolysis:

Autolysis is the self-destruction of a cell, tissue or organ with the help of lysosomes. It occurs in ageing, dead and diseased cells.

Question 9. What are vacuoles? How they are formed?
Answer:

Vacuoles:

Vacuoles are non-cytoplasmic areas present inside the cytoplasm. They are believed to be formed by expansion and pinching off from the endoplasmic reticulum.

Chapter 6 Living Organisms Short Answer Questions WBBSE

Question 10. What are cell inclusions or orgastic substances?
Answer:

Cell Inclusions or Orgastic substances:

These are non-living substances present in the cell. They may be organic or inorganic and may be present inside cells in soluble or insoluble states. Cell inclusions are generally of three categories—reserve food, excretory or secretory products and mineral matters.

Question 11. What are the principal types of cells?
Answer:

Principal types of cells:-

Cells are generally of two types—prokaryotic cells (ex-bacteria) and eukaryotic cells (plant and animal cells with true nuclei).

Question 12. Name the double-membraned and membrane-less cell organelles.
Answer:

Double membrane—Mitochondria and chloroplast. Membrane less—Ribosome and centrosome.

Question 13. What is a unit membrane?
Answer:

Unit membrane:

All cellular membranes (like plasma membrane, mitochondrial membrane, Golgi membrane, etc.), are similar in structure and hence it is called unit membranes. It is composed of protein and lipids.

Question 14. What is nuclear reticulum?
Answer:

Nuclear reticulum:

These are network-like structures found inside the nucleus of non-dividing cells. They are formed of DNA and protein. These structures condense during cell division and form chromosomes.

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 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 15. What are the characteristics of mammalian RBCs?
Answer:

Characteristics of mammalian RBCs

Mammalian RBCs are biconcave disc-like cells. They lack a nucleus and hence can hold more haemoglobin. This helps in carrying more oxygen to cope with higher metabolic activities.

Question 16. What are the advantages of multicellular organisms?
Answer:

Advantages of multicellular organisms:

  1. Different cell types help in the division of labour.
  2. Cells can adjust properly to the changing environment and can perform specialized functions.

Question 17. Write the characteristics of eukaryotic cells.
Answer:

Characteristics of eukaryotic cells:

  1. The cells have a definite nucleus.
  2. Definite chromosomes are present.

Membrane-bound cell organelles like— Mitochondria, Golgi bodies, etc., are found.

Question 18. Write the similarities between animal and plant cells.
Answer:

Similarities between animal and plant cells:

Both types of cells possess—

  1. nuclear membrane,
  2. true nucleus and
  3. membrane-bound cell organelles like- mitochondria, endoplasmic reticulum etc.

Question 19. What is a tissue?
Answer:

Tissue:

A group of cells of similar origin and function constitute a tissue. Every organ consists of many tissues. For example—our stomach contains epithelial, muscular, nervous and connective tissues.

Short Answer Questions for Structure of Living Organisms

Question 20. What is primordial utricle ?
Answer:

Primordial utricle:

In plant cells, due to the presence of a large vacuole, the nucleus and cytoplasm are pushed towards the periphery of the cell forming a thin layer beneath the cell membrane. This layer is known as a primordial utricle.

 

WBBSE Solutions For Class 8 School Science Chapter 6 The Structure of Living Organisms primordial uticle

 

Question 21. Write the differences between a Light microscope and an Electron microscope.
Answer:

Differences between a Light microscope and an Electron microscope:

Points of differences Light microscope Electron microscope
1. Illumination Visible light. A beam of electrons.
2. Lenses Glass lenses. Electron lens
3. Electricity Not required.  Required.
4. Contrast Achieved by dyes. Archived by use of heavy metals.
5. Size Small and portable. Large and fixed.
6. Magnification 2000-4000X. 50,000-3,00,000X.

 

Question 22. Write the differences between Unicellular and Multicellular organisms.
Answer:

Differences between Unicellular and Multicellular organisms:

Points of differences Unicellular Multicellular
1. Number of cells Single. Large number.
2. Function The same cell performs all functions. Not found. Different cells perform different functions.
3. Division of labour Not found.   Well observed
4. Size Microscopic Generally macroscopic.

 

Living Organisms Chapter 6 Study Guide WBBSE

Question 23. What is protoplasm? What is middle lamella?
Answer:

Protoplasm:

Protoplasm is the physical basis of life within which occurs all the vital functions of life. It is a viscous substance present inside the cell membrane of all living cells. It consists of cytoplasm, nucleus and vacuoles.

In multicellular plants, cells do not move as they are firmly joined together. The common cementing layer present between two adjacent cells is called the middle lamella.

 

WBBSE Solutions For Class 8 School Science Chapter 6 The Structure of Living Organisms Middle lamella

 

Question 24. Write the differences between Mitochondria and Chloroplast.
Answer:

Differences between Mitochondria and Chloroplast:

Points of differences Mitochondria Chloroplast
1. Colour Colourless. Generally green.
2. Occuranee All eukaryotic cells. Only in plant cells.
3. inner membrane. Become folded to form cristae. Unfolded and remain attached to thylakoids.
4. Energy source Convert chemical energy. Convert light energy.

 

Question 25. Write differences among Chloroplastid, Chromoplastid and Leucoplastid.
Answer:

Differences among Chloroplastid, Chromoplastid and Leucoplastid:

Chloroplastid Chromoplastid Leucoplastid
1. Green in colour. Coloured, other than green. Colourless.
2. Green chlorophyll pigment present.  Non-chlorophyll pigment is present. Pigments absent.
3. Found in leaves and stem Found in flowers, fruits etc. Found in the root.
4. Help in photosynthesis. Help in pollination and dispersal of seeds. Help in food storage.

 

Question Who discovered the nucleus? Draw a typical nucleus showing its structures.
Answer:

Robert Brown first discovered the nucleus.

 

WBBSE Solutions For Class 8 School Science Chapter 6 The Structure of Living Organisms nuclews

Short Answer Resources for Class 8 Structure of Living Organisms

Question 26. Write the differences between the Cell membrane and the Cell wall.
Answer:

Differences between the Cell membrane and the Cell wall:

Points of differences Cell membrane Cell wall
1. Location Both animal and plant cells. Only in plant cells.
2. Composition  Protein and lipid. Cellulose, hemicellulose, lignin, etc.
3. Nature Thin, elastic, living and semipermeable.  Thin, non-elastic, dead and permeable.

 

Question 28. Write the differences between Nucleoid and Nucleus.
Answer:

Differences between Nucleoid and Nucleus:

Points of differences Nucleoid Nucleus
1. Covering membrane Absent. Present.
2. Component absent Nucleolus absent. Nucleolus present.
3. Chromosome Absent.  Present.
4. Location Prokaryotic cell. Eukaryotic cell.

 

Question 29. Name the organelles which are described by the following-

  1. transporting channel of the cell
  2. A powerhouse of the cell
  3. Digestive bag of cell
  4. Control room of the cell

What is a prokaryotic cell?
Answer:

  1. ER
  2. mitochondria
  3. Lysosome
  4. nucleus

A cell having intermediate characters of prokaryotes and eukaryotes is called a eukaryotic cell. Ex: Marine photosynthetic dinoflagellates

Question 30. Write the differences between Mesosomes and Mitochondria.
Answer:

Differences between Mesosomes and Mitochondria:

Points of differences Mesosome Mitochondria
1. Location Prokaryotic cell. Eukaryotic cell.
2. Origin/Formation From the folding of the cell membrane. From pre-existing mitochondria.
3. Membrane Single membrane-bound  Double membrane-bound.
4. Cristae Absent. Present.

 

Question 31. Write the Difference between Nucleoplasm and Cytoplasm
Answer:

Difference between Nucleoplasm and Cytoplasm:

Points of differences Cytoplasm Nucleoplasm
1. Location In between the cell membrane and nuclear membrane. Inside the nuclear membrane.
2. Function Hold cell organelles. Hold nucleolus and nuclear reticulum.
3. Division Divisible into ectoplasm and endoplasm. No such division.

 

Question 32. Meristematic cells have a prominent nucleus and dense cytoplasm but they lack vacuole-why? What happens when

  1. The plasma membrane of a cell breaks down
  2. Golgi apparatus is removed from a cell?

Answer:

Meristematic cells lack vacuoles to regulate cell division continuously.

  1. The cell will die
  2. Lysosomes will not be formed.

Question 33. Write the differences between Golgi bodies and the Endoplasmic reticulum.
Answer:

Differences between Golgi bodies and the Endoplasmic reticulum:

Points of differences Golgi bodies Endoplasmic reticulum
1. Location Close to the nucleus. Scattered throughout the cytoplasm.
2. Types Only one type. Two types-rough and smooth.
3. Function Secretion. Protein and lipid synthesis. Also, form a cellular skeletal framework.

 

WBBSE Class 8 Science Practice Questions on Living Organisms

Question 34. Write the differences between the Endoplasmic reticulum and the Nuclear reticulum.
Answer:

Differences between the Endoplasmic reticulum and the Nuclear reticulum:

Points of differences Endoplasmic reticulum Nuclear reticulum
1. Nature Cell organelle. Part of the nucleus.
2. Structure Tubular. Network like.
3. Composition Membrane-bound. Made up of DNA and protein.
4. Function Form cellular framework. Carry hereditary material.

 

Question 35. Write the differences between the Rough endoplasmic reticulum and Smooth endoplasmic reticulum.
Answer:

Differences between the Rough endoplasmic reticulum and Smooth endoplasmic reticulum

Points of differences Rough ER Smooth ER
1. Structure Rough. Smooth.
2. Ribosomal association Ribosomes associated. Ribosomes are not associated.
3. Function  Help in protein synthesis. Help in the synthesis and storage of lipids.

 

WBBSE Class 8 Science Important Short Answers

Question 36. Write briefly about the structure of the centrosome. Mention its functions.
Answer:

Structure of the centrosome:

Centrosome consists of two parts: centrioles and centrosphere. Centrioles appear as two empty cylinders during cell division. They are situated at right angles to each other. Each cylinder is made up of fine microtubules arranged longitudinally.
The centrosphere is the clear homogeneous cytoplasm present around the centrioles. Functions:

  1. Centrioles are necessary for spindle formation during cell division
  2. The tail of spermatozoa is formed from one centriole.

 

WBBSE Solutions For Class 8 School Science Chapter 6 The Structure of Living Organisms centrosome

 

Question 37. Write the differences between nuclei and Nucleolus.
Answer:

Differences between nuclei and Nucleolus:

Points of differences Nucleus Nucleolus
1. Location Important cell organelle, present within the cytoplasm. Part of the nucleus is present in the nucleoplasm.
2. Membrane association Membrane-bound structure. Not bound by a membrane.
3. Function Control cellular activities and lodge genetic information. Help in the synthesis of ribosomal RNA.

 

Question 38. Some of the adaptations in animals are given below:

  1. White fur
  2. Strong tail
  3. a layer of fat under the skin
  4. thick skin
  5. Long beak.

Which of these adaptations are for polar regions? What do you mean by xerophytes?
Name the cells located in gills which can expel excess Na+ and Cl “from the body.
Answer:

Adaptations marked (1), (3) and (4). Plants growing in deserts or situations with a great dearth of water are called Xerophytes Example: Cactus Chloride cells (in gills).

WBBSE Class 8 School Science Chapter 6 The Structure of Living Organisms VSAQs

WBBSE Chapter 6 The Structure Of Living Organisms VSAQs

Question 1. Name the structural and functional unit of a living body.
Answer:

The structural and functional unit of a living body is the cell.

Question 2. Who observed cells for the first time? Robert Hooke (1965) observed dead cork cells in honey-comb-shaped

Answer: cell walls for the first time.

Question 3. Who observed living cells for the first time? Leeuwenhoek (1673) observed living cells like
Answer:

bacteria, protozoa, spermatozoa, red blood cells, etc., for the first time.

Question 4. Who discovered the microscope?
Answer:

The first microscope was built by Janssen (1590). It was first modified by Galileo (1610) and then by Robert Hooke.

Question 5. What is cell theory?
Answer:

Cell theory:

Cell theory states that all organisms are made up of cells.

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

Question 6. Who proposed cell theory?
Answer:

Cell theory was proposed by Schleiden and Schwann (1839).

Question 7. What is the source of illumination of a light microscope?
Answer:

Visible light is the source of illumination of a light microscope.

Question 8. Why electron microscope is named so?
Answer:

In the case of the electron microscope, the source of illumination is a beam of electrons.

WBBSE Class 8 Very Short Answer Questions Living Organisms

Question 9. How many lenses are used in the simple light microscope?
Answer:

Only one ocular lens is used in the case of a simple light microscope.

WBBSE Class 8 School Science Chapter 6 The Structure of Living Organisms VSAQs

Question 10. How many lenses are used in the compound light microscope?
Answer:

Three lenses are used in the compound light microscope.

Question 11. What types of lenses are used in light microscopes?
Answer:

Glass lenses are used.

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Question 12. What types of lenses are used in an electron microscope?
Answer:

Electromagnetic lenses are used.

Question 13. What amount of magnification can be achieved in the light microscope?
Answer:

The magnification can be about 2000-4000 times.

Question 14. What amount of magnification can be achieved in an electron microscope?
Answer:

A magnification of about 50,000 to 300,000 times can be achieved.

Structure of Living Organisms Chapter 6 WBBSE Answers

Question 15. Name a unicellular organism.
Answer:

Amoeba is a unicellular organism.

Question 16. Name two multicellular organisms.
Answer:

Mosquitoes, humans etc., are multicellular organisms.

Question 17. Give two examples of hexagonal-shaped cells.
Answer:

Examples of hexagonal-shaped cells:

Liver cells and meristematic tissue cells are hexagonal.

Question 18. Name algae having a filamentous body.
Answer:

Spirogyra looks like a thread or filament.

Question 19. What are pseudopodia ?
Answer:

Pseudopodia:

Pseudopodia are temporary cellular outgrowths from the body of Amoeba, which help in locomotion.

Question 20. Write about the shape of our RBCs.
Answer:

Shape of our RBCs:

The cells are circular disc-like and flattened at the centre.

Question 21. Which cells can receive stimuli from the environment and conduct it?
Answer:

Nerve cells are capable of these functions.

Question 22. Where in the animal body, fat is stored?
Answer:

Most fat of the animal body is stored beneath the skin.

WBBSE Class 8 Science Very Short Answer Format

Question 23. Where do we find stone cells?
Answer:

Stone cells:

Stone cells are found in the seed coat and fruit coat of some plants.

Question 24. Which tissue cells are responsible for the movement of food through the alimentary canal?
Answer:

Muscle tissue cells are mostly responsible.

Question 25. What is the main difference between meristematic tissue and permanent tissue?
Answer:

Meristematic tissue is composed of meristematic cells which are in a state of cell division to produce new cells.
A permanent tissue is composed of mature cells that have lost the power of cell division and have attained a permanent form.

Question 26. Name the tissue that forms the horn in mammals.
Answer:

Epithelial tissue

Question 27. Give an example of two cells that aid in vision.
Answer:

Rod cells and cone cells of the retina.

Question 28. Name two organelles of a plant cell that contain their genetic material and ribosomes.
Answer:

Plastids and mitochondria.

Question 29. Name two cells that do not possess a nucleus.
Answer:

Prokaryotic cells like those of bacteria and cyanobacteria.

Question 30. Name the yellow and orange pigments of chromoplastids.
Answer:

Yellow ⇒carotene ⇒Orange Zanthophyll

Question 31. Which cell organelle participates in cell division of animal cells?
Answer:

Centrosome

WBBSE Class 8 Science Chapter 6 Quick Answers

Question 32. Name the principal types of plant tissue.
Answer:

Two principal types—meristematic and permanent.

Question 33. Name the principal types of animal tissues.
Answer:

Four principal types—epithelial, connective, muscular, and nervous.

Question 34. Give two examples of connective tissue.
Answer:

Examples of connective tissue:

Blood and bones are connective tissue.

Question 35. Name two organelles that are formed from the cell membranes.
Answer:

Endoplasmic reticulum and Golgi bodies are formed from the plasma membrane.

Question 36. Name the part of protoplasm present inside the nucleus.
Answer:

Nucleoplasm is present inside the nucleus.

Question 37. What is the chemical name of a gene?
Answer:

Chemical name of a gene:

Deoxyribonucleic acid (DNA).

Question 38. State the function of the nucleolus.
Answer:

Function of the nucleolus:

It helps in the formation of ribosomes by forming ribosomal RNA.

Very Short Answer Questions for Class 8 Organisms

Question 39. What are cristae? Where it is found?
Answer:

Cristae:

These are finger-like projections of the inner mitochondrial membrane towards the matrix.

Question 40. From which cell organelles, enzymes, and hormones are synthesized?
Answer:

Golgi bodies.

Question 41. Which cell organelles are associated with the destruction of pathogens?
Answer:

Lysosomes are responsible for the destruction of some pathogens.

Question 42. What are rough endoplasmic reticulums?
Answer:

Rough endoplasmic reticulums:

The endoplasmic reticulums provided with ribosomes on their outer surface are called rough endoplasmic reticulums.

Question 43. What is histology?
Answer:

Histology:

The microscopic study of cells and tissues is known as histology.

Question 44. What is cytology?
Answer:

Cytology:

The study of cells is known as cytology.

WBBSE Class 8 Science Important Very Short Answers

Question 45. What is a histological stain?
Answer:

Histological stain:

These are chemical substances (generally colored and known as dyes) that help to differentiate different parts of a cell under a microscope.

Question 46. Write the characteristics of a desert region.
Answer:

Characteristics of a desert region:

The environment is very dry and hot, as is the minimum rainfall.

Question 47. What is a high-altitude environment?
Answer:

High-altitude environment:

The environment above the height of 15000 feet or more from ground level.

Question 48. What is antifreeze protein?
Answer:

Antifreeze protein:

These are protein molecules that prevent ice formation inside the cell.

Question 49. In which animals do we find antifreeze proteins?
Answer:

In animals which live in very dry and cold environments.

WBBSE Class 8 Very Short Answer Resources

Question 50. What is aerenchyma?
Answer:

Aerenchyma:

Aerenchyma is a modified parenchyma cell of plants, filled with enough air bubbles to help them float in water.

Question 51. What are chloride cells?
Answer:

Chloride cells:

These are some specialized cells found in animals living in salt water, which help to eliminate excess salt from the body.

Question 52. What are mesosomes?
Answer:

Mesosomes:

These are the structures found in bacterial cells, which compensate for the absence of mitochondria and help in respiration.

Question 53. Which animals can tolerate high acidity?
Answer:

Animals living in environments rich in decaying compounds.

Question 54. Why wing muscles of insects contain more mitochondria?
Answer:

Flapping of wings requires more energy.

Question 55. Where do you find myoglobin?
Answer:

Myoglobin:

Myoglobin is a protein found in muscle cells.

Question 56. Name one similarity between the nucleus and mitochondria.
Answer:

Both nucleus and mitochondria are double membrane-bound organelles.

Living Organisms WBBSE Study Guide for Short Answers

Question 57. What do you mean by polymorphism of Lysosomes?
Answer:

Polymorphism of Lysosomes:

Lysosomes are polymorphic, i.e. these have four main types based on morphology. These are primary lysosome, secondary lysosome, residual body and autophagic vacuole.

Question 58. Which cell organelle remains attached to the nuclear membrane?
Answer:

RER

Question 59. Identify the following cells—
Answer:

  1. spindle-shaped with both ends tapering helps in contraction and relaxation
  2. of isodiametric cells located in the stem or root tip, leaf bud etc.
  3. kidney-shaped, controls the opening and closing of stomata.
  4. a cell devoid of organelles like mitochondria, ER, Golgi bodies etc.
  5. Muscle cells
  6. meristematic cells
  7. guard cells
  8. Prokaryotic bacterial cell

Question 60. Bacteria do not have chloroplast but some bacteria are photoautotrophic in nature. Which part of bacterial cell performs photosynthesis?
Answer:

Bacteria do not have chloroplast but some bacteria are photoautotrophic in nature:

The photosynthetic pigments or thylakoids are present in the cytoplasm of bacterial cells that carry out photosynthesis.