Transcript notes

Objective: Be able to explain
mitosis and cytokinesis.
What is mitosis?
Mitosis:
division of the cell nucleus
Cytokinesis:
division of the cytoplasm
What is DNA
Chromosomes:
made up of DNA
not visible in cells except during mitosis
Chromosomes are made up of 2 sister
chromatids
What is a Chromosome?
1: sister chromatid (the
left side is one
chromatid, the right
side is another)
2: centromere:
attaches the two
chromatids
1
2
DNA is copied
Before mitosis occurs DNA is copied
One chromatid makes it’s sister chromatid
this makes up the chromosome
The left and right side of the chromosome
are identical.
Cell Cycle
Cells grow (G1)
DNA replicates (S phase)
Cell prepares for mitosis (G2)
Cell Divides
Interphase: everything a cell does when it
isn’t dividing (G1, S and G2)
Steps of Mitosis
Prophase
Metaphase
Anaphase
Telophase
(Pmat)
Prophase
Centrioles (anchors)
separate and spindles
(rope) form
Chromosomes appear
Metaphase
Chromosomes line up
Spindle (rope) connect
to the centromere of
chromosome
Anaphase
Centromeres split
Sister chromatids split
and move toward the
centrioles
Telophase
Chromosomes return to
their dense tangled
state (no longer
visible)
Nuclear envelope is
formed around each
cluster of
chromosomes
Cytokinesis
After mitosis is done
You have 2 nuclei in 1 cell now
Now the cytoplasm divides
Normally pinches into 2 cells