Question 6
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(a)(i) Name two diseases of the alimentary canal in humans [2 marks]
(ii) State two health effects of over-eating [2 marks](b) Explain the following terms in digestion:
(i) metabolism;
(ii) absorption. [6 marks]
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Observation
This question was attempted by many candidates and their performance was fair. In part (a)(i) few candidate correctly named diseases of the alimentary canal in humans, others wrote wrong answers such as kidney disease, inflammation of the stomach, liver failure and gall stone as diseases of alimentary canal in humans, in (a)(ii) candidates could not also correctly state effects of over-eating, some of the candidates wrote obesity as effect of over-eating.
In part (b) many candidates could not correctly explain metabolism and absorption as terms in
Digestion, they wrote wrong answers for metabolism as wastes excrete out from body or the sum of the chemical and physical process in an organism,they also wrote wrong answer for absorption as when food enters the mouth and most absorption takes place in the ileum/gradual process of absorbing food substances in the body in other to digest easily or the gradual process of absorbing food substances or nutrients in the body.
The expected answers are as follows:
6 (a) (i) DISEASES OF THE ALIMENTARY CANAL IN HUMANS
- cholera
- typhoid fever
- dysentery / amoebic dysentery
- diarrhoea/gastroenteritis
(ii) HEALTH EFFECTS OF OVER – EATING
- constipation / indigestion / dyspepsia
- discomfort / flatulence/ heart burn
(b) EXPLANATION OF TERMS IN DIGESTION
(i) METABOLISM
- Is a chemical process
- involving the breakdown
- and building up substances in the cells
(ii) ABSORPTION
- Is the transportation / movement
- of soluble digested food substances
- through the capillaries/villi into living cells