In girls, the first menstruation begins at puberty and is called .....

Arrange the hormones in the correct sequence from the beginning of the menstrual cycle.

Progesterone hormone is secreted by

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 menstrual cycle is:

When does the first menstrual cycle begin?