Luteinising hormone $(LH)$ in females:

The process of spermatogenesis and sperm formation is under the regulatory influence of

Sertoli cells are found in the testis. What are these cells called?

Given below are two statements :
Statement-$I$ : Each primary oocyte gets surrounded by a layer of granulosa cells and is called a primary follicle.
Statement-$II$ : At puberty,only $60,000-80,000$ primary follicles are left in each ovary.
In the light of the above statements,choose the most appropriate answer from the options given below :

Describe the structure of a sperm.

When does the reduction division occur during the process of gametogenesis?