Chapter 40.4, Problem 12SAQ

Summary Introduction

To determine:

The period when primary oocytes and spermatocytes are produced and also the number of gametes that result from one diploid cell in females and males.

Introduction:

Gametogenesis is a process that involves the formation of gametes. This process occurs in male and female at different period. In males, formation of sperms occurs in seminiferous tubules of testes. In females, oogenesis, or formation of ova or eggs, occur in ovary.

Explanation of Solution

Pictorial representation:

Fig 1: The spermatogenesis in male and oogenesis in female.

The process of spermatogenesis occurs with start of puberty. At the time of puberty and during adulthood, differentiation of these cells led to the development of diploid primary spermatocytes. It further goes for first meiotic division that produces two spermatocytes that led to the development of four haploid spermatids. They are joined by cytoplasmic bridges and become haploid cells by separating from each other. These spermatids mature to form sperms or spermatozoa

The process of oogenesis occurs in females. During this process, differentiation of oogonia occurs into primary oocytes. Since it occurs before birth, a female is born with primary oocytes. Meiosis results in four cells. All the cells become sperms after meiosis in males while only one cell becomes ovum in females.

Conclusion

The process of meiosis results into four cells. In females, only one cell goes to form ovum while in males, all the four cells become sperms