Give basic difference between spermatogenesis and oogenesis.

Oogenesis is fundamentally similar to spermatogenesis with regard to the behaviour of chromosomes. But there are important differences between oogenesis and spermatogenesis.

(i) one primary spermatocyte gives rise to four spermatozoa, but one primary oocyte forms only a single ovum.

(ii) when the primary spermatocyte divides, its cytoplasm is equally distributed between the two secondary spermatocytes formed, but during the division of the primary oocyte, almost all its cytoplasm goes to the daughter cell which forms the secondary oocyte. The other daughter cell (first polar body) though receives half the chromosomes of the primary oocyte, it does not receive any cytoplasm.