This question was attempted by many candidates and their performance was poor. In part (a)(i) candidates could not properly draw the diagram to illustrate the life cycle of a mosquito and in (a) (ii) candidates could not correctly describe how malaria is spread. In part (b) candidates correctly stated symptoms of malaria. In part (c) candidates could not correctly explain the following terms: transmission route and susceptible host..
The expected answers are as follows:
3(a)(i) Diagram of life cycle of mosquito and labelled stages
Accuracy - larva, pupa and imago must be segmented - 1 mark
- breathing tubes indicated in larva and pupa - 1 mark
Correct direction of arrows - 1 mark
Labelling -:
I - egg
II - larva
III - pupa
IV - imago/adult
*When diagram is absent mark the listed stages and arrows
(ii) How malaria is spread
- bites from infected mosquito
- female anopheles mosquito
- bites an infected person
- taking in the malaria parasite/plasmodium
- it transfers the parasite
- as it bites another person
(b) Symptoms of malaria
- urine turns yellow
- cold or chill
- shivering sets in/occurs
- high temperature/fever/sweating
- headache
- pains at the joints
- fatigue sets in/tiredness/weakness
- vomiting may occur
- loss of appetite
- anaemic condition
(c) Explanation of terms
This is the point/area of entry of pathogens of a particular diseases into a person
(ii) Susceptible host
A person who is easily infected by an infectious agent which causes a particular
disease |
