If fertilization does not occur in a female,which oocyte is shed during menstruation?

Which part of the sperm is formed from the centriole?

The cavity present in the Graafian follicle is:

How many ova and sperms would be produced from $100$ secondary oocytes and $100$ secondary spermatocytes during gametogenesis in humans?

Spermatogonia undergo a series of cell divisions to produce sperms. Select the correct statements from the following:
$A$. Spermatogonia always undergo meiotic cell division.
$B$. Primary spermatocytes divide mitotically to produce secondary spermatocytes.
$C$. Secondary spermatocytes, through their second meiotic division, produce spermatids.
$D$. Spermatids produce spermatozoa through mitosis.
$E$. Spermatids transform into spermatozoa by spermiogenesis.
Choose the correct answer from the options given below:

Provide a schematic labelled diagram to represent oogenesis.