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?

Consider the following:
$A.$ The reductive division for the human female gametogenesis starts earlier than that of the male gametogenesis.
$B.$ The gap between the first meiotic division and the second meiotic division is much shorter for males compared to females.
$C.$ The first polar body is associated with the formation of the primary oocyte.
$D.$ Luteinizing Hormone $(LH)$ surge leads to disintegration of the endometrium and onset of menstrual bleeding.
Choose the correct answer from the options given below:

For what primary purpose is the call of the cuckoo heard during the rainy season?

Ovulation takes place in/on

Explain the primary concept of the male and female reproductive systems.

In which organisms are macrolecithal eggs found?