Two kinds of division

The idea

Cell division forms new cells from pre-existing cells, letting organisms grow, repair tissues and reproduce; mitosis serves growth, repair, maintenance and asexual reproduction, while meiosis serves sexual reproduction and genetic diversity.

New cells, new jobs

Skin cells divide all the time to replace lost ones. But sperm and egg cells are made differently.

Do you think all cell division is the same?

• No. There are two types, for different jobs
• Yes, all cell division is identical
• Cells never divide

Which division?

Choose a situation. See which type of division it needs.

Mitosis and meiosis

Cell division forms new cells from pre-existing cells. It lets organisms grow, repair tissues and reproduce. There are two major types: mitosis, important for normal growth, repair, maintenance and asexual reproduction, and meiosis, important for sexual reproduction and genetic diversity.

Some cells, such as skin cells, divide continuously to replace cells that are lost regularly.

• Mitosis | Meiosis
• For | growth, repair, maintenance, asexual reproduction | sexual reproduction
• Where | most body cells | only cells of reproductive organs
• Result | more body cells | gametes, with genetic diversity

Notes

New cells form from pre-existing cells. Mitosis: growth, repair, maintenance, asexual reproduction. Meiosis: sexual reproduction and genetic diversity.

Check yourself

Cell division forms new cells from…

Which division produces gametes?

A plant makes pollen grains in its anthers. Which division is that?

• pre-existing cells — correct. Yes.
• nothing. New cells come from existing cells.
• the cell wall. New cells come from existing cells.
• Meiosis — correct. Yes.
• Mitosis. Mitosis makes body cells.
• Neither. Meiosis makes gametes.
• Meiosis — correct. Yes. In plants, meiosis occurs in the anthers and the ovaries.
• Mitosis. Pollen formation needs meiosis.
• Cell wall formation. It is a type of cell division.