
A diagram of a human sperm should include the following parts:
- Head: Contains the nucleus with genetic material.
- Acrosome: Contains enzymes that help in penetrating the egg.
- Midpiece: Contains mitochondria to provide energy for movement.
- Tail: Propels the sperm forward for fertilization.
(b) Explain the events which occur within a female Anopheles mosquito after it has sucked blood from a malaria patient.

A ladder of fixed length \( h \) is to be placed along the wall such that it is free to move along the height of the wall.
Based upon the above information, answer the following questions:
(iii) (b) If the foot of the ladder, whose length is 5 m, is being pulled towards the wall such that the rate of decrease of distance \( y \) is \( 2 \, \text{m/s} \), then at what rate is the height on the wall \( x \) increasing when the foot of the ladder is 3 m away from the wall?