NCERT Solutions for Class 7th Science
Chapter 2 - NUTRITION IN ANIMALS
(Complete Downloadable Chapter Solution PDF file is at the bottom of the page)
Q.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 (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.
Q.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 (a) Digestion of starch starts in the stomach. (F)
(b) The tongue helps in mixing food with saliva. (T)
Q.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
Q.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
Q.5 What are villi? What is their location and function?
Ans Villi (singular villus) are the finger-like outgrowths found in the inner walls of the small intestine. They increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials and then the absorbed substances are transported via the blood vessels to different organs of the body.
Q.6 Where is the bile produced? Which component of the food does it help to digest?
Q.7 Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Q.8 Why do we get instant energy from glucose?
Q.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 __________.
Q.10 Write one similarity and one difference between the nutrition in amoeba and human beings.
Q.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
Q.12 Label Fig. 2.11 of the digestive system.
Q.13 Can we survive only on raw, leafy vegetables/grass? Discuss.