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Question
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?
Solution
(a) (i) Gland A is salivary gland. (ii) Substance B is saliva. (iii) Enzyme C is salivary amylase.
(b) Tube D is oesophagus.
(c) The movement E is known as peristaltic movement.
(d) (i) F is hydrochloric acid, (ii) G is mucus and (iii) H is pepsin.
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