(a)(i) Diagram of human sperm cell
(ii) Sperm cell are produced in the testis(es) seminiferous, tubules and stored temporarily in the epididymis.
(b) The structure of the sperm cell enables it to function effectively in fertilization in the following ways:
(i) Acrosome: This is located at the anterior end of the head which contains lytic enzymes (agents) used to dissolve the egg membrane. it enhances the penetration of the egg during fertilization.
(ii) Middle piece: it contains numerous mitochondria which generate the energy used by the sperm cell to swim towards the egg.

(iii) Long whip-like tail or flagellum: This is found at the posterior end of the sperm cell. It propels or moves the sperm cell.
(iv)The Nucleus: The nucleus in found the head of the sperm cell contains genetic material which fuses with the nucleus of the egg/ovum.
(c) Advantages of sexual reproduction are:
(i) It permits variability of individuals, i.e., new varieties are produced.
(ii) It enhances survival in new or changing environment.
(iii) It allows for the production of hybrids for some desirable traits.
(iv) It provides the means for the maintenance of chromosome number from generation to generation.
(v) It enhances speciation or formation of new species and allows for the continuity of the species.