Advertisements
Advertisements
प्रश्न
What is digestion? Why do only animals require a digestive system?
Advertisements
उत्तर
Digestion is the process of breaking down complex food materials into simpler substances by the action of enzymes.
Need for a digestive system:
(i) Large complex molecules like carbohydrates, proteins and lipids need to be broken down to simpler molecules. These simpler molecules can then be absorbed and utilized by the body.
(ii) The breaking down of complex food molecules into their simpler form is possible only through the process of digestion.
(iii) During digestion, large complex macromolecules present in food are converted into small simpler molecules, which can be simplified in different compartments of digestive system only.
APPEARS IN
संबंधित प्रश्न
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 |
Name the biological catalysts which bring about chemical digestion of food.
When a person puts food in his mouth, then teeth cut it into small pieces, chew and grind it. The glands A in the mouth secrete a substance B which is mixed with the food by tongue. The substance B contains an enzyme C which starts the digestion of food in the mouth. The slightly digested food from the mouth goes down a tube D. The special type of movements E in the walls of tube D push the food into stomach for further digestion. The stomach wall secretes gastric juice containing three substance F, G and H. One of the functions of F is to kill bacteria which may enter the stomach with food. The substance G protects the inside layer of stomach from the damaging effect of substance F whereas substance H is and enzyme for digestion. The partially digested food then enters into small intestine for further digestion.
(a) What is (i) gland A (ii) substance B, and (iii) enzyme C?
(b) Name the tube D.
(c) What is the movement E known as?
(d) What are (i) F (ii) G, and (iii) H?
Explain the process of digestion of food in mouth, stomach and small intestine in human body.
Where does digestion of fat take place in our body?
Define the following term:
Peristalsis
Answer the following question.
Write two different ways in which glucose is oxidized to provide energy in the human body. Write the products formed in each case.
Define the following term:
assimilation
Write true or false for the below statement. Rewrite the false statements correctly.
Digestion of food in the intestine takes place in the presence of dilute hydrochloric acid.
Write true or false for the below statement. Rewrite the false statements correctly.
All the absorbed nutrients are immediately required by the body.
State whether the following statements are True or false: Pancreatic amylase digests protein into amino acids.
Match items in column A with the appropriate items in Column B:
| Column A | Column B | ||
| 1 | HCl | a | Lactose |
| 2 | Rennin | b | Pellagra |
| 3 | Enteropeptidase | c | Rumen |
| 4 | Cellulose | d | Pepsin |
| 5 | Ptyalin | e | Starch |
| 6 | Vitamin | f | Pernicious anaemia |
| 7 | Intestinal juice | g | Trypsin |
| 8 | Bile salt | h | Casein |
| 9 | Vitamin A | i | Micelle |
| 10 | Goitre | j | Night-blindness |
| k | Iodine | ||
Correct the spellings: HLC
Correct the spellings: Pespin
The question has four options. Choose the correct answer:
Trypsin is connected with the digestion of
Identify the INCORRECT statement.
In which of the following vertebrate group/groups, the heart does not pump oxygenated blood to different parts of the body?
Draw the diagram of the alimentary canal of man and label the following parts. Mouth, Oesophagus, Stomach, Intestine.
What is chyme?
Given below are two columns, Column I shows enzymes secreted by the glands in the alimentary canal of human beings and Column II indicates the components of food on which enzymes act. Choose the options showing correct matching:
