Study this page on the production of ova. When you are ready go to the page of problems on ova production. Make sure that you can recognise the different stages.

 

When you have completed both the work on this page (including the problems on ova production) and on the sexual cycle try the oestrus cycle quiz.

 

Ova Production

The production of ova involves cell division. Make sure that you know the difference between mitosis and meiosis.

The diagram below shows the stages in the production of ova inside an ovary.

Under the influence of hormones one or more (depending on the type of animal) of the primary follicles starts to develop. The photographs below show the stages of development.

Picture
Description
Primary follicles. Each of these is composed of a developing egg cell (primary oocyte) surrounded by a layer of follicle cells.

Developing ovarian follicles. The follicle cells divide and a fluid filled cavity is formed. The egg cell has become a secondary oocyte.

Mature ovarian follicle (a Graafian follicle in older texts). The follicle is now ready for ovulation when the secondary oocyte bursts through the ovary wall.
Corpus luteum. After ovulation the follicle cells form this glandular tissue that secretes progesterone.