Why do cells divide?

A cell divides so as to maintain a favourable Surface area to volume ratio.

A cell receives food and oxygen and turns out waste materials through it's membrane. A cell membrane of specific area can serve the contents of a particular volume only.Increase in the volume increases the requirements of the cell and this increases the need for greater membrane area.

Now,the Surface area of a sphere increase as the square of the radius and the volume of a sphere increases as the cube of the radius or to say, in simpler words,the volume of the cell increase more rapidly then the area of its membrane.

Hence, as a cell grows,it's membrane in due course of time becomes insufficient to move the required amount of substances in and out. The cell by dividing has a more favourable surface area to volume ratio. Thus, the cell divide so as to maintain it's size such that all it's requirements of nutrition,respiration and excretion are met.

Because they never learned how to add and subtract.

(And yes it does explain something--that the user Masquerade has absolutely no sense of humor whatsoever...)

For more information: go here: ===> http://www.bewilderingstories.com/issue124/cell_division.html

Exception: Quirkie, and Masquerate, and anyone else who lacks a sense of humor should NOT go there...

In eukaryotes (humans/complex organizms), our body cells divide to repair existing, damaged cells, or to make our body grow. This process is called mitosis, and the nucleus of the cell divides.

Our sex cells divide to produce more sperm/egg cells in a process known as meiosis.

In simple organizms, prokaryotes (single celled bacteria), they must divide for asexual reproduction. They're only single-celled, so division is the only way to make more of them. This process in bacteria is called binary fission (rather than cell division).

Mitosis, how else?
http://en.wikipedia.org/wiki/Mitosis

cells divide for growth, repair, or replacment of tissues. they also divide for reproduction

cells divide so yalls mommas can lick my butt

Because they are descended from generations of cells which divided before them. All sorts of things can destroy cells, so cells which did not divide would not leave descendants. In order to survive down to today, cells have to keep growing and dividing.

They dont just divide they can also multiply

u guys r smart... I said they only divide cuz they want to have a daughter.. HAHA .. no

ambot lang sad ngano nag research nga makabogo maan na hunong mo ug research it can cause danger to our loving mother earth who is now unconcious.............