Cell Replication
 Humans
are a diploid (2n) species; 46 chromosomes
 Humans gametes are haploid (n); 23 chromosomes
 1)
MITOSIS: division of a nucleus into two
genetically identical nuclei (IPMAT)

Somatic cells
 2)
MEIOSIS: division of nucleus that involves
two divisions and one duplication of
chromosomes; results in haploid (n) gametes
with one chromosome from each homogolous
pair

Gametes (sex cells)
 CYTOKINESIS:
division of a cells cytoplasm
into two distinct cells
1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. Telophase
6. Cytokinesis
1. Interphase
2. Prophase 1
3. Metaphase 1
4. Anaphase 1
5. Telophase 1
6. Cytokinesis 1
7. Prophase 2
8. Metaphase 2
9. Anaphase 2
10. Telophase 2
11. Cytokinesis 2
 Growth
and DNA
replication
Chromosomes
condense
 Nuclear membrane
begins to dissolve
 Spindle fibers
attach to the
centromeres
 Centrioles move to
opposite poles

 Chromosomes
line up
at the equatorial
plate
 Nuclear
membrane
completely dissolves
 Centromeres
divide and the
resulting
chromosomes
move to opposite
poles of the cell
 Identical
chromosomes at
each pole
 Chromosomes
lengthen
again
 Spindle fibres dissolve
 Nuclear membrane forms
 Cytokinesis:



Cytoplasm begins to
divide
A furrow develops
pinching of the cell into
two parts
Resulting in two separate
daughter cells
 Ana
and the pro wrestlers might be up your
alley...
X
X
 http://www.pbs.org/wgbh/nova/body/how-
cells-divide.html
 DNA
has already
duplicated
 Paternal
and Maternal
Chromosomes
duplicated
 Chromosomes
Synapsis
condense
 Homologous
chromosomes come
together (Tetrad)
 Crossing
 Spindle
over occurs
fibers attach to
homologous pairs
 Chromosomes
line up
at the equatorial
plate
 Homologous
chromosomes
separate to
opposite poles
 Nucleus
completes
its division.
 Results
in two cells
that are haploid (x2)
 Cytoplasm
divides
during cytokinesis
 Centrioles
move to
opposite poles
 Chromosomes
become
attached to spindle
fibres
 Chromosomes
line up at
equatorial plate
 Sister
Chromatids of
each chromosome
separate and move
to opposite poles
 Spindle
fibres
detach
 Cytoplasm
separates
(Cytokinesis)
 Left
with four
haploid cells