Class 7 Science Chapter 2 ‘Nutrition in Animals’ NCERT Solutions by Sciक्षक

Introduction

Before trying to attempt to answer the NCERT exercise questions, you should have a thorough understanding of class 7 Science chapter 2 i.e. ‘Nutrition in Animals‘.

If you haven’t understood the chapter yet, then worry not you can go through it easily and develop a crystal clear understanding of various concepts from our notes whose link has been provided below.

NCERT Exercise Questions and Answers

Que. 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 _____________.

Ans. 1 (a) The main steps of nutrition in humans are ingestion, digestion, absorption, assimilation and egestion.
(b) The largest gland in the human body is the 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.

Que. 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)

Ans. 2 (a) Digestion of starch starts in the stomach. (F)
(b) The tongue helps in mixing food with saliva. (T)
(c) The gall bladder temporarily stores bile. (T)
(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T)

Que. 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

(b) Water from the undigested food is absorbed mainly in the
(i) stomach (ii) food pipe (iii) small intestine (iv) large intestine

Ans. 3 (a) (iii) small intestine
(b) (iv) large intestine

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

Ans. 4 The matched items of Column I with Column II are:

Que. 5 What are villi? What is their location and function?

Ans. 5 Villi are the small finger-like projections or outgrowth that are present in the inner wall of the small intestine. Their main function is the absorption of the nutrients from the digested food in the small intestine and then passing them into the bloodstream. Villi increase the surface area of absorption in the small intestine.

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

Ans. 6 Bile is produced in the liver and stored in the gall bladder. It helps in the digestion of fats.

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

Ans. 7 The carbohydrate that can only be digested by ruminants is cellulose. Humans can’t digest cellulose because we don’t have the cellulose-digesting bacteria in our guts and also our digestive system doesn’t secrete any digestive juice(s) (enzyme) that can digest the cellulose.

Que. 8 Why do we get instant energy from glucose?

Ans. 8 Glucose is the simplest carbohydrate which can easily be absorbed into the bloodstream without the need for any digestion, unlike other carbohydrates. Then our cells perform respiration in which the glucose is broken down with the help of oxygen which provides energy to our body.

Que. 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 ________.

Ans. 9 (i) Small intestine.
(ii) Mouth or Buccal cavity.
(iii) Stomach.
(iv) Small intestine.
(v) Large intestine.

Que. 10 Write one similarity and one difference between the nutrition in amoeba and human beings.

Ans. 10 Similarities: (i)Both amoeba and human beings need food for their survival.
(ii) Food is digested in the body with the help of digestive juices.

Differences: (i) Human beings ingest the food via mouth whereas the amoeba engulfs the food with the help of pseudopodia.
(ii) The digestive juices in humans are secreted by the salivary glands, stomach, pancreas and small intestine whereas in amoeba they are secreted inside the food vacuole.

Que. 11 Match the items of Column I with suitable items in Column II

Ans. 11 The items of Column I and II are matched suitably as:

Que. 12 Label Fig. 2.11 of the digestive system.

Ans. 12 The labelled human digestive system diagram is as:

Que. 13 Can we survive only on raw, leafy vegetables/grass? Discuss.

Ans. 13 For some days, yes we can survive only on raw leafy vegetables but for a longer duration we can’t survive solely on leafy vegetables because they are mainly made up of cellulose and our body can’t digest cellulose so we will starve to death.

References & Credits

• Class 7th Science NCERT Textbook
• Image by avitalchn from Pixabay

Thank You for Choosing Sciक्षक ❤️