GENETICS: 3.3 - gametogenesis

What is gametogenesis?

The process of gamete production

What is spermatogenesis?

The process of sperm production in males

What does spermatogenesis produce?

4 daughter cells of equal size that become 4 mature sperm cells, each with n chromosomes

What is oogenesis?

The process of egg (ovum) production in females

What does oogenesis produce?

1 viable egg cell and 3 polar bodies, each with n chromosomes (due to unequal cytoplasm division)

Why are sperm cells smaller than egg cells?

Sperm are designed for movement; they are lightweight and streamlined

Why are egg cells larger than sperm cells?

They store nutrients in the cytoplasm for future cell division if fertilized

How many gametes are produced in males from meiosis?

4 sperm cells

How many gametes are produced in females from meiosis?

1 egg cell and 3 polar bodies (which degenerate)

When do males begin producing sperm?

At sexual maturity, producing hundreds of millions of sperm daily

What is a spermatogonium?

A male germ cell that undergoes meiosis to produce sperm

When do females begin egg development?

Before birth; oogonia are halted in prophase I

What happens at female sexual maturity?

Each month, one oogonium completes meiosis I before ovulation

When is meiosis II completed in females?

Only if the egg is fertilized

What are polar bodies?

Small, non-functional cells produced during oogenesis that eventually degenerate