Chapter 2 Levels Of Organization Of Life Organic And Inorganic Molecules Short Answer Type Questions
Question 1. What are vitamins?
Answer:
Vitamins:-
Vitamins are special components of food that are present in very little quantities, but they perform an elementary role in various physiological activities and in the development of immunity against different diseases.
Examples: Vit. A Vit. B, Vit. C, Vit. D, Vit. K, etc.
Question 2. What is meant by antivitamin? Give an example.
Answer:
Antivitamin:-
Certain organic compounds hinder the functions of some vitamins or denature some vitamins completely. These compounds are known as antivitamins.
Example: Galactoflavin is an antivitamin, which hinders the action of vitamin B12 or riboflavin.
Question 3. What is a pseudovitamin? Give an example.
Answer:
Pseudovitamin:-
A pseudovitamin is a substance that has a chemical structure similar to that of a vitamin but lacks the usual physiological effects of a vitamin. Example—Methylcobalamin is the pseudo vitamin of vitamin B12.
WBBSE Class Nine Life Science
Question 4. What is a Provitamin?
Answer:
Provitamin:-
The organic compound from which a vitamin is synthesized in the body of a living organism is called a provitamin.
Example: Vitamin A is synthesized in the liver from the liver from provitamin β-carotene.
Question 5. Mention the functions of vitamin A in the human body.
Answer:
The functions of vitamin A in the human body are as follows:
1. Vitamin A helps to maintain the health of the eye, tear gland, and retina.
2. It helps in maintaining healthy skin and muscle.
Question 6. Why vitamin A is called antixerophthalmic vitamin?
Answer:
Xerophthalmia is defined as the condition characterized by excessive and abnormal dryness of the eyeball, accompanied by conjunctivitis. This occurs basically due to the deficiency of vitamin A. Since vitamin A prevents Xerophthalmia, therefore it is called an antixerophthalmic vitamin.
Question 7. Mention the functions of vitamin D in the human body. Mention its sources.
Answer:
Functions of Vit.D:
1. Vitamin D helps in the uptake of phosphorus and calcium from the intestine.
2. It helps in the formation of teeth and bones.
Sources of Vit.D:
The sources of vitamin D are milk, cabbage, vegetable oil, cod liver oil, etc.
Question 8. why vitamin D is called antirachitic vitamin?
Answer:
Ricket is a disease caused by vitamin D deficiency. Since vitamin D helps in the prevention of the disease, therefore it is called antiricketic vitamin.
Question 9. Which vitamin is called anti sterility vitamin? Mention the main functions of this vitamin.
Answer:
Antisterility vitamin:
Vitamin E is called anti sterility vitamin.
Functions of vitamin E:
1. Vitamin E helps in the development of the embryo, reproductive organs, and muscles.
2. It helps to inhibit unwanted oxidation in the body by substances called free radicals.
Question 10. Which vitamin is called antihaemorrhagic vitamin? Mention the functions of this vitamin.
Answer:
Antihaemorrhagic vitamin:
Vitamin K is called the antihaemorrhagic vitamin.
Functions of vitamin K:
1. Vitamin K helps in prothrombin formation and blood coagulation.
2. It helps in the generation of energy in mitochondria.
Question 11. Which vitamin is called antiscorbutic vitamin? Mention the functions of this vitamin.
Answer:
Antiscorbutic vitamin:
Vitamin C is called antiscorbutic vitamin since it helps in preventing the disease scurvy.
The function of vitamin C:
1. It protects the body against some infections like common cough and cold.
2. It helps to keep bones and cartilage healthy.
3. It catalyzes the metabolism of carbohydrates.
Question 12. Mention the functions of Vitamin B3.
Answer:
The functions of vitamin B3 are as follows:
1. It catalyzes the transformation of carbohydrates to lipids.
2. It helps to stimulate the central nervous system.
3. It helps in cellular respiration and metabolism.
WBBSE Class Nine Life Science
Question 13. Which two vitamins help in cellular respiration? What is the similarity between iron and vitamin B12?
Answer:
Vitamin B1 and B2 help in cellular respiration.
Both iron and vitamin B12 help in the formation of red blood cells.
Question 14. Mention one function of chlorine. Write a function of manganese.
Answer:
The function of chlorine:
Chlorine helps to maintain the acid-base balance in the body.
The function of manganese:
Manganese regulates the normal level of carbohydrates in the blood.
Question 15. How do minerals control membrane permeability?
Answer:
Potassium (K) increases the membrane permeability of living cells whereas calcium (Ca) restricts it. Thus, mineral elements play an important role in controlling membrane permeability in the body.
Question 16. Mention some plant and animal sources of | food that are rich in magnesium.
Answer:
Plant sources of magnesium:
The plant sources of magnesium are green vegetables, grains, groundnut, bean, soybean, peas, etc.
Animal sources of magnesium:
The animal sources of magnesium are fish, chicken, egg, milk, etc.
Question 17. Mention some plant and animal sources of food that are rich in iron.
Answer:
Plant sources of iron:
The plant sources of iron are pulses, whole-wheat flour, spinach, lettuce, banana, etc.
Animal sources of iron:
The animal sources of iron are fish, eggs, mutton, liver, etc.
WBBSE Class Nine Life Science
Question 18. Which elements and vitamins help in the formation of our skeletal structure?
Answer:
Calcium (Ca) and phosphorus (P) are the main building components of bones and teeth. Similarly, vitamin D and vitamin C are the vitamins which also help in the formation o tee and bones. Thus, these elements and vitamins take part in the formation of the skeletal structure of the human body.
Question 19. Mention two animal sources and a plant source of calcium.
Answer:
Two animal sources of calcium are fish and egg and a plant source of calcium is pea.
Question 20. What is the function of sodium in the human body?
Answer:
The functions of sodium in the human body are as follows:
1. It helps to maintain the cardiac cycle, blood pressure, blood volume, and acid-base balance.
2. It helps in the conduction of nerve impulses.
3. It also helps to maintain the density of urine.
Question 21. Mention a plant source and an animal source of sodium.
Answer:
A plant source of sodium is vegetables and an animal source of sodium is butter.
Question 22. Which diseases are caused due to deficiency of vitamins A, G, D, and B12?
Answer:
Deficiency of Vitamin A – Xerophthalmia.
Deficiency of Vitamin C – Scurvy.
Deficiency of Vitamin D – Rickets.
Deficiency of Vitamin B12 – Pernicious anemia
Question 23. Mention deficiency diseases of one water soluble and one fat soluble vitamins.
Answer:
Vitamin C is a water-soluble vitamin. Its deficiency causes scurvy.
Vitamin D is a fat soluble vitamin. Deficiency of this vitamin causes rickets in children.
Question 24 Name the vitamins, which act as antioxidants. Mention the significance of antioxidants.
Answer:
Vitamins acting as antioxidants:
Vitamins A, C, E, and P act as antioxidants.
Significance of antioxidants: Free radicals induce cell aging. Antioxidants destroy free radicals and thus help to keep our bodies fit.
Question 25 Mention the functions of the vitamin B complex.
Answer:
The functions of the vitamin B complex are:
1. Vitamins B and B help in amino acid metabolism.
2. Vitamin B2 helps in the activation of other vitamins.
3. Vitamin B3 and B5 take part in the formation of NADP and Coenzyme A respectively, which take part in different metabolic reactions.
4. Vitamin B6, B7, and B12 take part in fat metabolism.
5. Vitamin B9, and B12 help in DNA synthesis.
Question 26 What happens in case of folic acid deficiency?
Answer:
In the case of folic acid deficiency, the following anemia Megaloblastic occurs-
1. and Leucopoenia.
2. Weakening of muscles.
3. Loss of weight and disruption of mental stability.
Question 27 What is meant by macronutrients?
Answer:
The elements, which are essentially required in larger quantities to maintain normal growth and nutrition and deficiency which are distinctly noticeable in our body, are called macronutrients. Example-Calcium, phosphorus, etc.
Question 28 Name the macronutrients, required for the human body.
Answer:
Following are the macronutrients required for the human body-Calcium, phosphorus, magnesium, sodium, potassium, etc.
Question 29 What is meant by micronutrients?
Answer:
The elements which are required in little quantities for normal growth and nutrition and deficiency of which are not distinctly noticeable in our body, are called micronutrients. Example-Molybdenum, boron, etc.
Question 30. Name some micronutrients required for the human body.
Answer:
Following are some of the micronutrients required for the human body-Iron, copper, boron, zinc, iodine, etc.
Question 31. Mention two important roles of magnesium.
Answer:
Two important roles of magnesium are:
1. It takes part in the formation of bones and teeth.
2. It controls muscle contraction and the function of the nervous system.
Question 32 Mention the importance of potassium.
Answer:
The importance of potassium is:
1. It regulates heart rate and muscle contraction.
2. It directly takes part in neural transmission and guides different cellular reactions.
Question 33 Mention the relation between calcium and he relation betwee vitamin D.
Answer:
Vitamin D helps in calcium absorption in the body. In the absence of this vitamin, calcium uptake in bones and teeth is hindered. Thus vitamin D helps in adding calcium to bones and teeth.
Question 34 What will happen, if the level of sodium drops in the blood?
Answer:
In case of deficiency of sodium in the blood, hyponatremia may occur. In this situation, there will be a severe scarcity of water in the body followed by a sharp decline in blood pressure.
Question 35. What is the importance of iodine in human nutrition?
Answer:
Similar question:
Mention one importance of iodine. Iodine is an essential component of thyroxine hormone. This hormone plays a very important role in controlling the metabolic rate of our body. Deficiency of this hormone causes goiter. Thus, iodine is one of the most important micro-elements needed for nutrition in humans.
Question 36. How does the increased level of fluorine in drinking water cause harm to the human body?
Answer:
Increased levels of fluorine in drinking water may cause damage to teeth and bones. The enamel of the teeth becomes weak and turns brownish in colour. It also results in the formation of a cavity leading to a condition called dental fluorosis.
Apart from this, fluorine forms a cementing layer on the spine and bones of the legs, resulting in the loss of their natural flexibility. In addition to this, high fluoride ingestion can also cause a range of gastrointestinal symptoms like nausea, pain, and vomiting.
Moreover, excess fluoride level in the body results in polyuria (frequent urination), polydipsia (excessive thirst), and constipation followed by diarrhea.
