Cells divide to replace old, dead, or damaged cells.
Cells also divide so living things can grow. When organisms
grow, it isn't because cells are getting larger. Organisms grow
because cells are dividing to produce more and more cells.
In human bodies, nearly
two trillion cells divide
every day.
In cell division, the cell that is dividing is called the "parent" cell. The parent
cell divides into two "daughter" cells. The process then repeats in what is
called the cell cycle.
Depending on the type of cell,
there are two ways cells
divide—mitosis and meiosis.
Each of these methods of cell
division has special
characteristics.
One of the key differences in mitosis is a single cell divides
into two cells that are replicas of each other and have the
same number of chromosomes. This type of cell division is
good for basic growth, repair, and maintenance.
In meiosis a cell divides into four cells that have half the
number of chromosomes. Reducing the number of
chromosomes by half is important for sexual reproduction
and provides for genetic diversity.
Summary: Asexual reproduction relies on a process called mitosis, in
which the nucleus of a cell divides to create two new nuclei, each
containing an identical copy of DNA. Mitosis allows the cells in your body
to divide and regenerate—your hair to grow, your skin to heal after being
wounded.