Lesson: Nutrition in Animals

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 __________.

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

(e) Amoeba digests its food in the ____________.

Solution:

(a) Ingestion, digestion, absorption, assimilation and egestion.

(b) Liver

(d) Villi

(e) 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)

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

Solution:

(a) False

(b) True

(d) True

Question: 3

Tick (√) marks 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

Solution:

(a) iii

(b) iv

Question: 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

Solution:

Column I Column II

Food components Product(s) of digestion

Carbohydrates Sugar

Proteins Amino acids

Fats Fatty acids and glycerol

Question: 5

What are villi? What is their location and function?

Solution:

Villi are small finger-like outgrowths found in the inner walls of the small intestine in the human digestive system. They help in the absorption of digested food by increasing the total surface area of the walls.

Question: 6

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

Solution:

Bile juice is produced in the liver. It helps in the digestion of fat by breaking down larger fat droplets into smaller ones, making it easier for the pancreatic juices to digest fat.

Question: 7

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

Solution:

Cellulose (a carbohydrate) can be digested by ruminants but not by humans.

This is because the ruminants have a large sac-like structure known as the rumen that is located between oesophagus and small intestine. It is in this rumen that cellulose is digested by the help of some bacteria, which are not found in human bodies.

Question: 8

Why do we get instant energy from glucose?

Solution:

Glucose, which is a simple sugar, is formed when carbohydrate gets broken and digested in human bodies. It gets absorbed in the blood and requires no further digestion, and thus, it can act as a source of instant 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 ________________.

Solution:

(i) Small intestine

(ii) Buccal cavity

(iii) Stomach

(iv) Small intestine

(v) Large intestine

Question: 10

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

Solution:

Similarity:
Amoeba and human both show holozoic type of nutrition. Holozoic nutrition involves intake of food, followed by various chemical procedures where the food is digested and absorbed by the body, and finally egestion where the waste products are removed from the body.

Difference:
Human beings show a lengthy series of complex digestive procedures that include ingestion, digestion, assimilation, absorption, and egestion of food; while Amoeba follows a simple process where it engulfs the food with the help of pseudopodia, and the food is digested in the food vacuole.

Question: 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

(d) Rectum (iv) Acid release

(e) Small intestine (v) Digestion is completed

(f) Large intestine (vi) Absorption of water

(vii) Release of faeces

Solution:

Column I Column II

(a) Salivary gland (iii) Saliva secretion

(b) Stomach (iv) Acid release

(d) Rectum (iv) Storage of undigested food

(e) Small intestine (v) Digestion is completed

(f) Large intestine (vi) Absorption of water

Question: 12

Label the figure of the digestive system.

Solution:

Question: 13

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

Solution:

Humans will not be able to survive only on raw, leafy vegetables or grass. This is because the raw leafy vegetables or grass are rich in cellulose, which humans cannot digest, owing to the lack of a rumen and cellulose-digesting enzymes in their bodies.