NCERT Solutions for Class 7 Science Chapter 2 – Nutrition in Animals are important as they cover many new topics essential for your academic growth. Below given solution can be accesed online.
NCERT Solution for Class 7 Science Ch 2 - Nutrition in Animals
Exercise Questions with Answers
1. Fill in the blanks:
(a) The main steps of nutition 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 ...............
Answers :
(a) ingestion, digestion, absorption, assimilation , egestion.
(b) liver
(c) digestive
(d) villi
(e) food vacuole
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)
Answers :
(a) F (b) T (c) T (d) T
3. Tick (✔) 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
4. Match the items of Column I with those given in Column II :
| Column I | Column II |
|---|---|
| Food components | Product(s) of digestion |
| Carbohydrates | Fatty acids and glycerol |
| Proteins | Sugar |
| Fats | Amino acids |
| Column I | Column II |
|---|---|
| Food components | Product(s) of digestion |
| Carbohydrates | Sugar |
| Proteins | Amino acids |
| Fats | Fatty acids and glycerol |
5. What are villi ? What is their location and function ?
Answer :
Villi are finger-like projections or outgrowths found in the small intestine of our digestive system. They increase the surface area for the absorption of digested food.
6. Where is the bile produced ? Which component of the food does it help to digest ?
Answer :
Bile juice is produced in the liver and aids in the digestion of fats by breaking down large fat globules into smaller ones.
7. Name the type of carbohydrate that can be digested by ruminants but not by humans. Give reason also.
Answer :
Cellulose is a carbohydrate that can be digested by ruminants but not by humans, as humans lack the cellulase enzyme necessary for its digestion.
8. Why do we get instant energy from glucose ?
Answer :
Glucose is a simple sugar that is easily absorbed into the blood, while other carbohydrates must first be broken down into glucose before they can be absorbed. Therefore, glucose provides instant energy.
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 .............
Answers :
(i) Small intestine
(ii) Buccal cavity
(iii)Stomach
(iv) Small intestine
(v) Large Intestine
10. Write one similarity and one difference between the nutrition in amoeba and human beings.
Answer :
Similarity: Both amoeba and human beings follow the holozoic type of nutrition.
Difference:
- Humans intake food through the buccal cavity.
- In amoeba, food is ingested through pseudopodia.
11. Match the items of Column I with suitable items in Column II
| Column I | Column II |
|---|---|
| (a) Salivary gland | (i) Bile juice secretion |
| (b) Stomach | (ii) Storage of undigested food |
| (c) Liver | (iii) Saliva secretion |
| (d) Rectum | (iv) Acid release |
| (e) Small intestine | (v) Digestion is completed |
| (f) Large intestine | (vi) Absorption of water |
| (vii) Release of faeces |
Answer :
| Column I | Column II |
|---|---|
| (a) Salivary gland | (iii) Saliva secretion |
| (b) Stomach | (iv) Acid release |
| (c) Liver | (i) Bile juice secretion |
| (d) Rectum | (ii) Storage of undigested food |
| (e) Small intestine | (v) Digestion is completed |
| (f) Large intestine | (vi) Absorption of water |
12. Label Fig. 2.11 of the digestive system.
Answer :
13. Can we survive only on raw, leafy vegetables/grass ? Discuss.
Answer :
No, we cannot survive solely on raw, leafy vegetables because they primarily consist of cellulose, which we are unable to digest due to the absence of a cellulose-digesting enzyme in our bodies.