NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals

Exercises

Question:- 1. Fill in the blanks:

(a) The main steps of nutrition in humans are __________, __________, __________, _________ and __________.

(b) The largest gland in the human body is __________.

(c) The stomach releases hydrochloric acid and ___________ juices which act on food.

(d) The inner wall of the small intestine has many finger-like outgrowths called _________.

(e) Amoeba digests its food in the ____________ .

Answer:- (a) The main steps of nutrition in humans are ingestion, digestion, absorption, assimilation, and egestion.

(b) The largest gland in the human body is liver.

(c) The stomach releases hydrochloric acid and digestive juices which act on food.

(d) The inner wall of the small intestine has many finger-like outgrowths called villi.

(e) Amoeba digests its food in the food vacuole.

Question:- 2. Mark ‘T’ if the statement is true and ‘F’ if it is false:

(a) Digestion of starch starts in the stomach. (T/F)

(b) The tongue helps in mixing food with saliva. (T/F)

(c) The gall bladder temporarily stores bile. (T/F)

(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)

Answer:- (a) Digestion of starch starts in the stomach. (False)

(b) The tongue helps in mixing food with saliva. (True)

(c) The gall bladder temporarily stores bile. (True)

(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (True)

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

(a) Fat is completely digested in the

(i) stomach          (ii) mouth       (iii) small intestine       (iv) large intestine

Answer:- (iii) small intestine       

 (b) Water from the undigested food is absorbed mainly in the

(i) stomach       (ii) foodpipe       (iii) small intestine       (iv) large intestine

Answer:- (iv) large intestine

Question:- 4. Match the items of Column I with those given in Column II:

Answer:-

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

Answer:- Villi are little finger-like projections that emerge from the small intestine’s walls. They improve the surface area available for digested food absorption. The nutrients from the digested meal can be absorbed via the blood vessels found within the villi.

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

Answer:-Bile juice is secreted by the liver and stored in the gallbladder. The bile serves a very important role in fat digestion.

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

Answer:- Cellulose is a carbohydrate that can be digested by ruminants but not by humans due to a lack of the cellulase enzyme essential for cellulose digestion.

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

Answer:- Glucose is a simple sugar that is quickly absorbed by the blood, whereas other carbs must first be converted down into glucose before being absorbed; as a result, glucose provides immediate energy.

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

(i) absorption of food                           ________________.

(ii) chewing of food                              ________________.

(iii) killing of bacteria                           ________________.

(iv) complete digestion of food         ________________.

(v) formation of faeces                       ________________.

Answer:- (i) absorption of food                           Small intestine

(ii) chewing of food                              Buccal cavity

(iii) killing of bacteria                           Stomach

(iv) complete digestion of food         Small intestine

(v) formation of faeces                       Large intestine

Question:- 10. Write one similarity and one difference between the nutrition in amoeba and human beings.

Answer:-  Similarity:- The holozoic type of nutrition is followed by both amoeba and humans.

Difference:- Humans intake food through buccal cavity whereas amoeba intake food through pseudopodia.

Question:- 11. Match the items of Column I with suitable items in Column II

Answer:-

Answer:-

Question:- 12. Label Fig. 2.11 of the digestive system.

Answer:-