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Mitosis & Meiosis
Chromosome
Diploid/Haploid cells
 Any
cell with two chromosome
sets is a diploid cell, abbreviated
2n.
 Any cell containing a single set of
chromosomes are haploid cells,
abbreviated n.
Normal Male
2n =
46
4
Normal Female
2n =
46
5
Mitosis
 Identical
 Used
for asexual reproduction
 “Body” cell is created
 One cycle
 Genetic clone
 One diploid = two diploids
Mitosis
http://www.johnkyrk.com/mitosis.html
Meiosis
 Not
identical
 Used in sexual reproduction
 Gamete: Sex cells are created
 Two cycles
 Creates genetic variation
 One diploid = four haploid cells
MEIOSIS
Mitosis
 Identical
 Asexual
 “Body” cell is
created
 One cycle
 Genetic clone
 One diploid =
two diploids
Meiosis
 Not identical
 Sexual
 Gamete: Sex
cells are created
 Two cycles
 Creates genetic
variation
 One diploid =
four haploid cells
Meiosis
The production of sex cells, which are
not genetically identical, through a
series of cell divisions.
 Ensures that organisms have the same
number of chromosomes in each
generation.

Let’s look at the difference
When mitosis takes place an identical
diploid cell is created.
 One original cell + new copy = two
diploid cells
 But, when meiosis takes place cells that
are not identical are being made.
 One original haploid + three new haploid
cells = four haploid cells.

•The
cells that are created are called
gamete cells or sex cells
•It
is a two-step process that reduces
the chromosome number by half—
from 46 to 23—to form sperm and
egg cells.
This is a reduction in genetic
material.
When cells join at
fertilization, each
contributes 23
chromosomes so the
resulting embryo will have
the usual 46.
Meiosis also allows
genetic variation through
a process of DNA
shuffling while the cells
are dividing.
http://www.johnkyrk.com/meiosis.html