Class 7 Science

Animal Nutrition

NCERT Solution

Question 1: Fill in the blanks.

  1. The main steps of digestion in humans are _____ ____ _____ _____ ______
  2. The largest gland in human body is _______
  3. The stomach releases hydrochloric acid and _____ juices which act on food.
  4. The inner wall of the small intestine has many finger like structure called _______.
  5. Amoeba digest its food in the ________

Answer: (a) ingestion, digestion, absorption, assimilation and egestion, (b) liver, (c) digestive juices, (d) villi, (e) food vacuole

Question 2: Mark T if the statement is true and F if it is false

  1. Digestion of starch starts in the stomach.
  2. The tongue helps in mixing food with saliva.
  3. The gall bladder temporarily stores bile.
  4. The ruminants bring back swallowed grass into their mouth and chew it for some time.

Answer: (a) F, (b) T, (c) T, (d) T

Question 3: Tick (√) mark the correct answer in each of the following.

a. Fat is completely digested in the

  1. Stomach
  2. Mouth
  3. Small intestine
  4. Large intestine

Answer: (iii) Small intestine

b. Water from the undigested food is absorbed mainly in the

  1. Stomach
  2. Food pipe
  3. Small intestine
  4. Large intestine

Answer: (iv) Large intestine

Question 4: Match the column

Column AColumn B
(1) Food components(a) Products of digestion
(2) Carbohydrates(b) Fatty acid and glycerol
(3) Proteins(c) Sugar
(4) Fats(d) Amino acids

Answer: (1) a, (2) c, (3) d, (4) b

Question 5: What are villi? What is their location and function?

Answer: Villi is the finger like projections. These are found in the inner walls of small intestine. It helps in absorption of the digested food.

Question 6: Where is the bile produced? Which component of the food does it digest?

Answer: Bile is produced in the liver. Bile helps in digestion of fats.

Question 7: Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.

Answer: Cellulose is the type of carbohydrates which is digested in ruminants but not in humans. Ruminants have a large sac –like structure between the small intestine and large intestine, in which cellulose of the food is digested by the action of certain bacteria. Such structure is not present in human. Hence human cannot digest cellulose while ruminants can.

Question 8: Why do we get instant energy from glucose?

Answer: Glucose is simple sugar so there is no need of digestion. It directly reaches the cells where it gives energy after respiration.

Question 9: Which part of the digestive canal is involved in:

  1. Absorption of food ________
  2. Chewing of food ________
  3. Killing of bacteria ________
  4. Complete digestion of food _______
  5. Formation of faeces _________

Answer: (a) small intestine, (b) mouth, (c) stomach, (d) small intestine, (e) large intestine

Question 10: Match the following column

Column IColumn II
(A) Salivary gland(1) Bile juice
(B) Stomach(2) Absorption of water
(C) Liver(3) Saliva secretion
(D) Rectum(4) Acid release
(E) Small intestine(5) Release of faeces
(F) Large intestine(6) Storage of undigested food

Answer: A -3, B - 4, C- 1, D- 5, E - 2, F- 6

Question 11: Label the diagram of the digestive system.


digestive system