(i) Draw and label the human sperm cell. (ii) State where the sperm cell is produced and where it is stored. (b) Explain how the structure of the sperm cell...

(a)(i) Labelled diagram of a human sperm cell

(ii) Sperm cells are produced in the seminiferous tubules of the testes and are stored temporarily in the epididymis.

(b) How the structure of the sperm cell enables it to function in fertilisation

1. The acrosome, situated at the tip of the head, contains enzymes which digest the egg membrane and enable the sperm to penetrate the egg.
2. The nucleus in the head contains a haploid set of chromosomes. It carries the male genetic material which fuses with the female nucleus during fertilisation.
3. The middle piece contains numerous mitochondria which release energy for movement of the sperm.
4. The long, whip-like tail or flagellum beats to propel the sperm through the female reproductive tract towards the egg.
5. Its small, streamlined shape reduces resistance as it swims towards the ovum.

(c) Four advantages of sexual reproduction

1. It produces variation among offspring.
2. The variation enables some individuals to survive changes in the environment and resist diseases.
3. It permits the combination of desirable characteristics from two parents, producing improved varieties or hybrids.
4. It maintains the chromosome number of a species from one generation to the next.