Question

Define oogenesis and when it occurs in a human female.

a. Sperm formation; throughout reproductive life
b. Egg formation; before puberty
c. Egg formation; during menstrual cycle
d. Sperm formation; during pregnancy

Answer 1

Oogenesis is the process of egg formation in the ovaries of a female fetus. It starts with oogonia dividing and forming primary oocytes, which are then arrested in the stage of meiosis I.

Step-by-step explanation:

Oogenesis is the process of producing eggs in the ovaries of a female fetus. It begins with oogonia, the ovarian stem cells, that divide via mitosis and form primary oocytes in the fetal ovary prior to birth. These primary oocytes are then arrested in the stage of meiosis I and resume it years later, beginning at puberty and continuing until menopause. The number of primary oocytes present in the ovaries declines throughout a female's life.