Solution of Chapter 2. Nutriton in Animals (NCERT Science Book)

Exercise

1

Fill in the blanks:

a. The main steps of digestion 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 _________.
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.


d. The ruminants bring back swallowed grass into their mouth and chew it for some time.
3

Fat is completely digested in the

i. stomach


ii. Mouth


iii. Small intestine


iv. Large intestine
3

Water from the undigested food is absorbed mainly in the

i. stomach


ii. Food pipe


iii. Small intestine


iv. Large intestine
4

Match the items of Columns 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
5

What are villi? What is their location and function?
6

Where is the bile produced? Which component of the food does it digest?
7

Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
8

Why do we get instant energy from glucose?
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 faces ________.
10

Write at least one similarity and one difference between nutrition in amoeba and human being.
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 faces
12

Label figure of the digestive system:
13

Can we survive only raw, leafy vegetables/grass? Discuss.
1

Visit a doctor and find out:

i. Under what conditions does a patient need to be on a drip of glucose?


ii. Till when does a patient need to be given glucose?


iii. How does glucose help the patient recover?
2

Find out what vitamins are and get the following information.

i. Why are vitamins necessary in the diet?


ii. Which fruits or vegetables should be eaten regularly to get vitamins?
3

Collect data from your friends, neighbours and classmates to know more about milk teeth.

Tabulate your data. One way of doing it is given below:


S. No.



Age at which first tooth fell



Age at which last tooth fell



No. of teeth lost



No. of teeth replaced



1.







2.







3.







4.







5.







Find out from at least twenty children and find the average age at which children lose the milk teeth. You may take help of your friends.