The menstrual cycle is typically completed in:

The menstrual cycle occurs in:

Which hormone is essential for ovulation?

Which hormone level is required for ovulation in females?

Given below is a flow chart showing ovarian changes during the menstrual cycle. Fill in the spaces by providing the names of the hormones responsible for the events shown.
$\boxed{\text{Primary follicles}}$
$\downarrow \leftarrow \boxed{A}$
$\boxed{\text{Graafian follicle}}$
$\downarrow \leftarrow \boxed{B}$
$\boxed{\text{Ovum}}$
$\downarrow \leftarrow \boxed{C}$
$\boxed{\text{Corpus luteum}}$

The corpus luteum formed during the post-ovulatory phase of the menstrual cycle survives for only . . . . . . weeks in the absence of fertilization.