The Process of Cell Division
Learning Objectives
 Describe the role of chromosomes in cell division.
 Name the main events of the cell cycle.
 Describe what happens during the four stages of
mitosis.
 Describe the process of cytokinesis.
Warm up
 Define these words
 Chromosome
 Chromatin
 Cell cycle
 Chromatid
 Centriole
12/10
Chromosomes
In prokaryotic cells, DNA is packaged into a single, circular
chromosome.
Chromosomes
In eukaryotic cells, DNA is packaged into multiple chromosomes.
Chromosomes make it possible to separate DNA precisely during cell
DNA
division
double
helix
coils
sister
chromatids
centromere
nucleosome
supercoils
histone
proteins
Prokaryotic Cell Cycle
Prokaryotes undergo binary fission.
• Binary Fission is cell
division in a single celled
organism produces 2
genetically identical
organism
• Form of asexual
reproduction
• Result – produces 2
genetically identical cells
Eukaryotic Cell Cycle
Eukaryotic cells have a more complex cell cycle than
prokaryotic cells.
Interphase is divided
into 3 parts
• G1 phase: cell growth
• S phase: DNA
replication
• G2 phase: preparing
for cell division
Which Cell Cycle?
bacteria
plants
M Phase
Cell division occurs during M phase.
M Phase: cell division
• Mitosis
• Cytokinesis
1st Phase of Mitosis: Prophase
• The genetic material inside the nucleus condenses and the
duplicated chromosomes become visible.
• The spindle begins to form.
Centromere attaches the
duplicated strand of DNA
molecules
Chromatid also called sister
chromatid, is a duplicated
stand of a chromosome
Centrioles are microtubules
that form spindle fibers to
separate chromosomes
2nd Phase of Mitosis: Metaphase
Chromosomes line up at the center of the cell.
centrioles
chromatid
centromere
Spindle fibers
connect the
centromere of
each
chromosome to
the two poles of
the spindle
chromosome
3rd Phase of Mitosis: Anaphase
• Sister chromatids separate
• Chromosomes move toward opposite poles.
individual
chromosomes
4th Phase of Mitosis: Telophase
•
•
•
•
The cell begins to divide into daughter cells.
Nuclear envelope reforms
Spindles begins to break apart
Nucleolus becomes
visible in each daughter
nucleus
nuclear envelopes
re-forming
Cytokinesis
Cytoplasm pinches in the center to form two daughter cells.
• The division of the cytoplasm
• 1 cell splits into 2
Mitosis Overview
List and describe the stages of mitosis.
Interphase
Cytokinesis
1 Prophase
4 Telophase
2 Metaphase
3 Anaphase