NIOS Class 12 Biology Intext Solutions Nutrition and Digestion

NIOS Biology Intext Solutions Chapter 13

INTEXT QUESTIONS 13.1

1. List the five major steps in animal nutrition

Ingestion, digestion, absorption, assimilation, egestion

2. What is intracellular digestion? Give example of an organism showing intracellular

digestion.

All five steps of digestion occur inside the cell itself. Paramecium, Amoeba etc.

INTEXT QUESTIONS 13.2

1. Match the characteristics in column A with the parts of digestive system given in column B

Column A	Column B
Characteristics	Part
(1) Common passage for air breathed in and the food swallowed.	(a) Small intestine
(7) Largest gland in the body	(b) Pancreas
(3) Has three limbs-ascending, transverse and descending	(c) Duodenum
(4) Longest part of the food canal	(d) Pharynx
(5) Receives bile and pancreatic juice	(e) Appendix
(6) Narrow worm-shaped projection	(f) Stomach
(8) Gland located in the bend of the duodenum	(g) Colon
(8) Gland located in the bend of  duodenum	(h) Liver

Ans: d, 2. f, 3. g, 4. a, 5. c, 6. e, 7. h, 8. b

2. Name the three salivary glands and mention their location in the mouth cavity.

• Parotid – in front of and below the ear
• Submaxillary – inner side of lower jaw.
• Sublingual – below the tongue

INTEXT QUESTIONS 13.3

1. How is grinding of food in the mouth helpful in digestion?

Smaller particles provide a larger surface area for digestive action.

2. Name the source gland for following enzymes.

(i) amylase

(ii) pepsin..

(iii) lipase…

• (i) Salivary glands
• (ii) Stomach
• (iii) Pancreas

3. List at least four enzymes that contribute towards digesting proteins.

• 1. Pepsin
• 2. Trypsin,
• 3. Chymotrypsin,
• 4. Carboxypeptidase.

INTEXT QUESTIONS 13.4

1. In which part of the alimentary canal does maximum absorption of water occur?

Colon/large intestine.

2. List any three ways in which the intestine increases the surface area for absorption?

• (i) very long
• (ii) villi
• (iii) microvilli

3. Which end products of digestion are absorbed by

(i) blood capillaries of intestinal villi? …..

(ii) Lacteals?.

• (i) Amino acids and simple sugars,
• (ii) fatty acids and glycerol.

INTEXT QUESTIONS 13.5

1. Mention the source of secretion and the effect of the following:

(i) Gastrin.

(ii) Enterogastrone

(i) Gastrin-stomach, stimulates the secretion of gastric juice

(ii) Enterogastrone-Duodenum stops the secretion of gastric juice.

INTEXT QUESTIONS 13.6

1. Name any three substances related to the blood, produced by liver.

Fibrinogen, prothrombin, heparin

2. List any three substances which the liver stores.

Sugar/glycogen, iron, vitamin A/D/B12

3. What happens to excess amino acids absorbed from gut?

Broken down to produce sugar and urea, sugar is used, and urea is excreted.

INTEXT QUESTIONS 13.7

1. (a) A doctor advises a person to sip ORS at regular intervals because he/she was suffering from diarrheoa. What is this ORS?

(b) Name any one causative agent of diarrhoea in developing countires.

(c) During the rainy season there is a rise in diarrhoea cases. What piece of advice will you give to your younger brother/sister to prevent oneself from getting diarrhoea?

• (a) Oral Rehydration Solution, which is drinking water containing a pinch of sugar and salt. Its consumption prevents dehydration.
• (b) Rota virus / E.coli
• (c) Wash hands with soap and water before eating/wash raw vegetables well before cooking or consuming/cover food so that flies cannot sit on it / consume clear, uncontaminated water.

2. A little girl/boy had a problem in passing stool. The faeces were dry and hard. The doctor said that this was because the child was not taking adequate amount of fibres in the diet and was not taking proper diet at proper time. What is this child suffering from?

Constipation

3. What is dyspepsia? What are its symptoms?

 Indigestion or upset stomach. Symptoms–Stomach pain

4. Which organ of the body is involved in jaundice and how can you make out that a person is suffering from jaundice.

The liver is involved in jaundice. The urine and eyes of the affected person will appear yellow.

Additional Study Materials

• Chapter 06 Root system
• Chapter 07 Shoot system
• Chapter 08 Absorption, Transport, and Water Loss in Plants
• Chapter 09 Nutrition in plants – Mineral Nutrition
• Chapter 10 Nitrogen Metabolism
• Chapter 11 Photosynthesis
• Chapter 12 Respiration in Plants