Transcript What is the difference between mitosis and meiosis?

What is the
difference
between
mitosis and
meiosis?
library.thinkquest.org
Vocabulary
 Mitosis: The phase in the cell cycle
during which the nucleus divides
 Meiosis: A part of sexual reproduction in
which cells divide to form sperm cells in a
male and egg cells in a female. Meiosis
occurs only in reproductive cells.
Vocabulary
 DNA: deoxyribonucleic acid, a chemical that
contains information for an organism’s growth and
functions
 Chromosomes: the physical structure in a cell that
contains the cell’s DNA (genetic material)
 Cell cycle: the normal sequence of development
and division of a cell
 Genome: All the DNA of an organism, including its
genes; the genetic material of an organism.
Mitosis and Meiosis
 Create two cells from one cell!
 there has to be enough stuff for both cells
to be able to live
 so, there has to be duplication of a lot of
stuff before the first cell (parent) divides.
Mitosis and Meiosis
 One of the things to duplicate is the
genome.
 These are the chromosomes which are
made up of DNA.
 Once the DNA replicates (makes 2 copies
of everything from what the parent originally
had), the cell can divide.
Mitosis and Meiosis
 There are now 4 chromosomes of each type
 we started out with our usual 2 of each
 most organisms have 2 of each chromosome
and they differ slightly from each other- this
becomes important for meiosis
 then when everything is duplicated, we get 4!
Differences of Mitosis and
Meiosis
 MITOSIS
 the 2 cells that come out of the division
(daughters) are EXACTLY the same in
genetic makeup as the original mother
cell.
 They have the very same DNA and
therefore make the same proteins and
therefore the cells behave the same.
Differences of Mitosis and
Meiosis
 MEIOSIS
 Purpose of meiosis is to make new types of cells!
(the cells are not the same at all)
 Eggs and sperm are products of meiosis
 Genetic diversity happens from mixing of genes
inside the cells of the mother and father
 Why do you have traits given to you from your
grandmother through your father, even though your
father may not have that trait ?
(he carries it in his genes for later mixing)