presentation

1. The Cell Cycle: Mitosis

2. The Cell Cycle

3. Mitosis: results in
genetically
identical daughter
cells

4. Mitosis for growth and replacement

5. Mitosis for asexual reproduction
in single-celled Eukaryotes

6. Cells Live, Cells Divide, and Cells Die
Apoptosis is a
good thing

7. G1 phase
(normal cell function
and cell growth)
S phase
(DNA replication)
G2 phase
(additional growth
and preparation
for division)
G0 phase
(nondividing)
The Eukaryote Cell Cycle

8. Remember! DNA Replication occurs
during S phase of Interphase.

9. Interphase: G1 Interphase: S phase
Interphase
: G2
Mitosis: Prophase
Mitosis:
Anaphase

10. Naked DNA
(all histones
removed)
Nucleosome
Histones
Scaffold
protein
Centromere
Identical
sister
chromatids
Replicated
chromosome
Moderately
compacted
chromatin
Highly compacted
chromatin
NucleusCell
Loosely
packed
chromatin
Chromosomes condense

11. Mitosis P
M
A
T

12. Mitosis
• Prophase
• Prometaphase
• Metaphase
• Anaphase
• Telophase
Cytokinesis

14. ANAPHASE TELOPHASE CYTOKINESIS G1, EARLY INTERPHASE
Centromeres split as sister
chromatids separate and
move to opposite poles of cell.
Nuclear envelope and nucleolus
form at each pole. Chromosomes
decondense. Spindle disappears.
Division of the cytoplasm
into two cells.
Cells resume normal functions
or enter another division cycle.
Contractile
ring
LM 20 µm
LM 20 µm LM 20 µm
LM 10 µmLM 10 µm
LM 10 µm
(all animal): ©Ed Reschke/Photolibrary/Getty Images; (all plant): ©Ed Reschke

15. Contractile
ring
Cleavage
furrow
Cleavage
furrow
Cytokinesis in progress Cytokinesis complete
TEM (false color) 10 µm
Cell plate composed
of vesicles
Cell wall
Cytokinesis in progress
Microtubules LM
25 µm
Cytokinesis complete
Two cell
walls
Nucleus
NucleusCell plate
Cytokinesis

16. MITOSIS
MITOSIS
FERTILIZATION
MEIOSIS MEIOSIS
Gametes
(sperm and egg cells)
Zygote
(fertilized egg)
Another reason for cell division: a new
organism

17. Cell membrane
DNA
Cell wall
Parent cell contains
one chromosome.
DNA replicates and
attaches to cell
membrane.
Membrane growth
between the two
attachment points
moves the DNA
molecules apart as
new cell wall material
is deposited.
The result of
binary fission: two
daughter cells,
each identical to
the original.
Prokaryotes - Binary Fission
(A new cell is a new organism)

19. G2 checkpoint
• Has all DNA replicated?
• Can damaged DNA be repaired?
• Is spindle-making machinery
in place?
Metaphase
checkpoint
• Do kinetochores
attach to spindle?
• Are chromosomes
aligned down
equator?
S phase checkpoint
• Is DNA replicating
correctly?
S phase
(DNA replication)
G2 phase
(additional growth
and preparation
for division)
G1 phase
(normal cell function
and cell growth)
G1 checkpoint
• Is DNA damaged?
G0 phase
(nondividing)
Regulation of
Cell Division
Prevents out of control growth

20. Term Definition
Chromatin
Cleavage furrow
Chromosome A single, continuous molecule of DNA wrapped around protein. Eukaryotic cells contain multiple linear
chromosomes, whereas bacterial cells typically have one circular chromosome.
Collective term for all of the DNA and associated proteins in a cell
Chromatid One of two identical attached copies that make up a replicated chromosome
Centromere A small part of a chromosome where sister chromatids attach to each other
Interphase Stage of the cell cycle in which chromosomes replicate and the cell grows
G1 phase
G0 phase
G2 phase
S phase
Gap stage of interphase in which the cell grows and carries out its functions
Gap stage of interphase in which the cell functions but does not divide
Gap stage of interphase in which the cell produces membrane components and spindle proteins
Synthesis stage of interphase when DNA replicates
Mitosis
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokinesis
Cell plate
Centrosome
Spindle
Kinetochore Protein complex to which the spindle fibers attach on a chromosome’s centromere
Array of microtubule proteins that move chromosomes during mitosis
Structure that organizes the microtubules that make up the spindle in animal cells
Material that forms the beginnings of the cell wall in a plant cell undergoing cytokinesis
Indentation in cell membrane of an animal cell undergoing cytokinesis
Distribution of cytoplasm to daughter cells following division of a cell’s chromosomes
Stage of mitosis when chromosomes arrive at opposite poles and nuclear envelopes form (telo- = end)
Stage of mitosis when the spindle pulls sister chromatids toward opposite poles of the cell
Stage of mitosis when chromosomes line up along the center of the cell (meta- = middle)
Stage of mitosis when the nuclear membrane breaks up and spindle fibers attach to kinetochores
Stage of mitosis when chromosomes condense and the spindle begins to form (pro- = before)
Division of a cell’s chromosomes into two identical nuclei
Cell Cycle Vocabulary

21. Cell Cycle Practice
At each step, fill in the main events and sketch a cell
with 4 chromosomes

22. Interphase: G1 phase
Main events Sketch

23. Interphase: S phase
Main events Sketch

24. Mitosis: Prophase
Main events Sketch

25. Mitosis: Metaphase
Main events Sketch

26. Mitosis: Anaphase
Main events Sketch

27. Mitosis: Telophase
Main events Sketch

28. Cytokinesis
Main events Sketch