Differentiate between primary oocyte and a secondary oocyte.

Hint: A female germ cell involved in fertilization is called an oocyte. It's also known as ovum, or egg cell, in other words. It occurs in the ovarian follicle, a specialized unit of the ovary, during the course of oogenesis/folliculogenesis in the cortex. And it is one of the largest cells in the body (approximately \[110m\] in diameter).

Complete answer:


Additional information:
During female gametogenesis, the ovary produces an oocyte. Oogonia is formed when female germ cells create a primordial germ cell (PGC), which then undergoes mitosis. The oogonia become primary oocytes during oogenesis. In a cryo conservation oocyte is stored in the form of genetic material.

Note:
In most anisogamous species, the egg cell, or ovum (plural ova), is the female reproductive cell, or gamete (organisms that reproduce sexually with a larger, "female" gamete and a smaller, "male" one). When the female gamete is unable to move, this word is used (non-motile). When you ovulate, the egg is released from the follicle in a matter of minutes or hours. The egg is only viable for \[12 - 24\] hours after it is released, and it must be fertilized by sperm within that time frame.