Mitosis Step by Step
Mitosis Model
• Each string of beads
represents a
chromosome
• Each bead represents
a gene
• Red (ish)
chromosomes
inherited from mother
• Blue (ish)
chromosomes
inhertited from father
Mitosis Model
• In this example, the
cell has a
chromosome
complement of 4
• This is known as the
DIPLOID NUMBER
• What is the Diploid
Number for Humans?
Interphase
• The Chromosomes
shorten and thicken
and become visible
under the microscope
(if stained)
Nuclear
Membrane
Prophase
• Each Chromosome
replicates itself
• This is where DNA
replication (studied in
Unit 1 comes in)
• The chromosomes
are made up of
2CHROMATIDS held
together by a
CENTROMERE (not
shown)
Chromosome
Chromatid
Chromatid
Centromere
Metaphase
• Spindle fibres form
• The Chromosomes
line up, at random,
along the equator of
the spindle
Anaphase
• The spindle fibres
contract pulling the
chromatids apart and
to opposite poles of
the cell
• Once separated, the
chromatids are now
known as
chromosomes
Telophase
• 2 new “Daughter”
cells are formed
• Nuclear membrane
reforms
End Result
Mother cell
How do the cells
compare
• With the mother cell?
• With each other?
• Why is Mitosis
important?
Daughter cells