An egg with yolk in the center and cytoplasm surrounding it is known as:

Choose the correct option for human reproduction.

$A$ female of $24$ years age attained puberty at the age of $14$ years. She has two children born by normal delivery. How many polar bodies are formed in her body till date $($each $\text{M.C.}$ is of $30$ days$)$ :-

If the nuclei from an $8$-celled stage of an embryo are transplanted into enucleated eggs,which of the following events is likely to occur?

Identify True/False statements. Correct each false statement to make it true.
$(a)$ Androgens are produced by Sertoli cells. (True/False)
$(b)$ Spermatozoa get nutrition from Sertoli cells. (True/False)
$(c)$ Leydig cells are found in ovary. (True/False)
$(d)$ Leydig cells synthesise androgens. (True/False)
$(e)$ Oogenesis takes place in corpus luteum. (True/False)
$(f)$ Menstrual cycle ceases during pregnancy. (True/False)
$(g)$ Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False)

Which two events in the life cycle maintain the same (constant) number of chromosomes?