Cell division and growth:
- mitosis- two identical cells being produced from the orginal cell
- the chromosomes contain the genes which must be passsed to each new cell
- at first, plant and animal cells are unspecialised and they are called stem cells
- cells divide to form two daughter cells. each nucleus contains four chromosomes.
gametes--> sex cells that are produced by meiosis
in humans, the gametes are the sperm and the ova
sexual reproduction results in variation .
before divison, a copy of each chromosome is made
the cell divides twice to form 4 gametes
each gamete has a single set of chromosomes each with a different combination of genes.
- unspecialised cells
- found in the human embryo and bone marrow
- stem cells change into all the different types of body cells
- stem cells can be used to cure some diseases