K.C.S.E Biology Q & A - MODEL 1997PP1QN06
Oil can be applied on the stagnant water to control the spread of malaria.
(a) How does this practice control the spread of malaria?
(b) Give a reason why this practice should be discouraged
(a) Mosquito larvae/ Pupae are killed; Accept suffocation/ Breaking life cycle of Mosquitoes
(b) Pollution of environment/ oil expensive, other aquatic are killed; accept Contamination.