Cockroach egg is called as

Onset of menstruation is due to

There is a connective tissue cord extending between the testis and abdominal wall called

In eggs which have very thick and resistant membrane e.g., fishes and insects sperm penetrate through a special canal called

Each seminiferous tubule is lined on its inside by two types of cells $A$ and $B$. Which of the following options is correct, w.r.t. the type of cell and its function?