An overview of the discovery of cell division, mitosis. For centuries people accepted the “spontaneous generation” of life from inanimate matter.

New cells are created from existing cells through a process called the cell cycle. One cell can make a copy of itself and form two new daughter cells. This happens during mitosis, or the M phase of the cell cycle. During mitosis, cells build a molecular machine, which is known as the mitotic spindle.

The generally accepted parts of modern cell theory include: All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms.

New cells arise from pre-existing cells.

By MSNBC’s Paige Williams. Ultimately, we stop growing because we are genetically programmed to do so. It is our genes, made of DNA, that determine how we grow and develop. We inherit our genes from our parents when we are conceived, and we maintain this genetic blueprint throughout life.

Why don’t cells just stretch when you grow, instead of making copies of themselves? The muscles in the cells can’t stretch that far. The cell won’t be able to bring in food fast enough or get waste out fast enough. The cell membrane doesn’t like the feeling of stretching.

Plant cell walls have both elastic — or reversible-stretching — and plastic — or irreversible-stretching — properties that allow the walls to be flexible enough to expand with growth, but strong enough to remain intact. The more it can stretch, the more readily it will grow.”

Plant cell walls have both elastic — or reversible-stretching — and plastic — or irreversible-stretching — properties that allow the walls to be flexible enough to expand with growth, but strong enough to remain intact. The more it can stretch, the more readily it will grow.”