Re: What is meiosis and mitosis? What's the diferance?

Mitosis is essentially normal cell division. When a cell divides (because an 
an organism is growing for example) then the DNA of that cell is replicated
so that there are 2 copies. Upon cell division, one copy goes to one
daughter cell and the other copy to the other daughter cell.


Meiosis is a special type of cell division to generate gametes (sperm and
egg (oocyte) cell or whatever type of reproductive cell and organism has).
These cells need to be haploid unlike normal cells which are diploid.

Eucaryotes are generally diploid. So each cell has 2 copies of every
chromosome (these are very similar but not identical copies, one comes
from your mother, the other from your father). During mitosis described 
above, each daughter cell gets a copy of each, so it remains diploid.
During meiosis, you need to generate haploid cells (the sperm and egg are
haploid cells). When the sperm fuses with the egg, the resulting cell
now has one set of chromosomes from the sperm and one from the egg, hence 
it is diploid again. 

Meiosis is a special cell division whereby a diploid cell divides to 
generate haploid progeny which are the gamete cells.