Chapter 8: Nutrition explains how living organisms obtain and utilize nutrients for energy and growth. This post presents Class 9 Biology Chapter 8 MCQs, helping students revise the chapter’s core concepts such as types of nutrition, heterotrophic and autotrophic nutrition, human digestive system, and importance of a balanced diet.
1. What is nutrition?
- A. Process of respiration
- B. Process of obtaining and using food ✅
- C. Process of reproduction
- D. Process of digestion
Explanation: Nutrition is the process by which organisms take in food and utilize it for growth and energy.
2. Which type of nutrition involves organisms making their own food?
- A. Autotrophic ✅
- B. Heterotrophic
- C. Parasitic
- D. Saprophytic
Explanation: Autotrophs like plants synthesize their food through photosynthesis.
3. Which part of the plant is responsible for photosynthesis?
- A. Root
- B. Leaf ✅
- C. Stem
- D. Flower
Explanation: Leaves contain chlorophyll which traps sunlight needed for photosynthesis.
4. What is the primary source of energy in a human diet?
- A. Proteins
- B. Vitamins
- C. Carbohydrates ✅
- D. Fats
Explanation: Carbohydrates are the main energy-providing component of food.
5. Which organ releases bile for digestion?
- A. Stomach
- B. Liver ✅
- C. Pancreas
- D. Small intestine
Explanation: The liver produces bile which aids in the digestion of fats.
6. What is the role of saliva in digestion?
- A. Digests proteins
- B. Breaks down starch ✅
- C. Absorbs nutrients
- D. Emulsifies fats
Explanation: Saliva contains the enzyme amylase which starts the digestion of starch.
7. Where does the digestion of proteins start?
- A. Mouth
- B. Stomach ✅
- C. Small intestine
- D. Large intestine
Explanation: The stomach secretes pepsin which begins protein digestion.
8. What is a balanced diet?
- A. Food rich in one nutrient
- B. Diet containing all essential nutrients ✅
- C. Only vegetarian food
- D. High-fat diet
Explanation: A balanced diet provides all nutrients in proper amounts for good health.
9. Which nutrient is necessary for body growth and repair?
- A. Fats
- B. Proteins ✅
- C. Carbohydrates
- D. Vitamins
Explanation: Proteins are building blocks needed for tissue repair and growth.
10. Which vitamin is essential for good vision?
- A. Vitamin A ✅
- B. Vitamin C
- C. Vitamin D
- D. Vitamin K
Explanation: Vitamin A is important for the maintenance of healthy eyesight.
11. Which structure absorbs nutrients in the small intestine?
- A. Stomach lining
- B. Villi ✅
- C. Large intestine
- D. Pancreas
Explanation: Villi increase the surface area for absorption of digested food in the small intestine.
12. What is the function of the large intestine?
- A. Absorption of water ✅
- B. Digestion of proteins
- C. Digestion of fats
- D. Enzyme production
Explanation: The large intestine absorbs water and forms feces.
13. Kwashiorkor is caused by deficiency of:
- A. Proteins ✅
- B. Fats
- C. Carbohydrates
- D. Vitamins
Explanation: Protein deficiency leads to diseases like kwashiorkor, especially in children.
14. Which enzyme digests fats?
- A. Pepsin
- B. Lipase ✅
- C. Amylase
- D. Trypsin
Explanation: Lipase breaks down fats into fatty acids and glycerol.
15. Which part of the digestive system has acidic pH?
- A. Mouth
- B. Stomach ✅
- C. Small intestine
- D. Liver
Explanation: The stomach has hydrochloric acid, creating a low pH suitable for protein digestion.