This question was attempted by many candidates and their performance was good. In part (a)
candidates wrote wrong answers such as tuberculosis, droplet as classes of communicable
diseases. In part (b) candidates correctly defined mode of transmission of a disease, signs and
symptoms of a disease.
The expected answers were as follows:
7 (a) Classes of communicable diseases
- air-borne diseases/droplets
water/food-borne diseases
insect-borne disease
worm infestation
animal-borne disease
contact disease.
(b) In Explaining the terms
(i) Mode of transmission
This is a method or way in which diseases are transferred from one organism to
another.
It may be by water, air, insect and animal etc.
(ii) Signs and symptoms
These are the observable things shown by the organism affected by disease;
Such as emaciation/thin, loss of weight, yellow eye, pale looking etc.