The cell cycle consists of interphase and the M phase. Interphase includes G1, S, and G2 phases where the cell grows and duplicates its DNA. The M phase is when the cell divides through mitosis and cytokinesis. Mitosis consists of prophase, metaphase, anaphase, and telophase where the chromosomes align and separate. Cytokinesis then divides the cell cytoplasm. Uncontrolled cell division can lead to cancer.

2. CELL CYCLE

4. • DNA synthesis - the process by which copies of nucleic acids are
strung together to form a longer DNA sequence.
• Restriction Point - one of several points in the eukaryotic cell
cycle at which the progression of a cell to the next stage in the
cycle can be halted until conditions are favorable (e.g. the DNA
repaired).
• Replication - The process of duplicating or producing an exact
copy of a polynucleotide strand such as DNA.
• Chromosomes -
KEYWORDS

5. • In order for adult multicellular organisms to develop from
a single fertilized egg, cell growth and division has to
occur at the appropriate times and in the appropriate
places.
• When cell cycles proceed inappropriately (e.g., cells divide
uncontrollably), pathological conditions like cancer can
result.
OVERVIEW

6. •Cells must accomplish two basic things during the
cell cycle:
• Copying cellular components
• Dividing the cell so that components are distributed
evenly to the daughter cells
•The alternating “growth” and “division” activities of
the cell is called the “cell cycle”.

7. M phase

8. INTERPHASE

9. INTERPHASE: G1 PHASE
• Events during G1
oCell growth
oPreparation of chromosomes for
replication
oDuplication of cellular components
oG1 checkpoint (or restriction point); cell
commits to division or exits from cell
cycle

10. • DNA containing cell’s genetic
code
• Each chromosome has a
matching pair
-- Homologous Pair
• During interphase, each
chromosome copies itself

11. INTERPHASE: G0 PHASE
• Also known as G1 checkpoint.
• During the G0 phase, the cell cycle machinery is dismantled and
cyclins and cyclin dependent kinases disappear.
• Cell then remain in the G0 phase until there is a reason for them
to divide.
• Some cell types in mature organisms enter the G0 phase semi-
permanently and can be induced to being dividing again only
under very specific conditions.
• Other types of cells, such as epithelial cells, continue to divide
throughout an organism's life and rarely enter G0.

12. INTERPHASE: S PHASE
• DNA replication
• Duplication of the centrosome
• The centrosome is located near the nucleus of the cell and
contains the microtubule organizing center in animal cells.
It contains two centrioles that migrate to the poles before
cell division and serve to organize the spindle.

13. INTERPHASE: S PHASE

14. INTERPHASE: G2 PHASE
• Cell growth
• Checkpoint (restriction point) for entry into M phase.

16. MITOSIS
Mitosis begins after G 2 and ends
before G 1

18. CELL DIVISION: M PHASE
• Process that divides cell nucleus to produce two new
nuclei each with a complete set of chromosomes
• Continuous process
• Four phases (PMAT)
• Prophase
• Metaphase
• Anaphase
• Telophase

19. Cytokinesis

20. MITOSIS
Mitosis is divided into 4 phases :
1. Prophase – 1st phase (longest)
2. Metaphase – 2nd phase
3. Anaphase – 3rd phase
4. Telophase – 4th (final) phase
(think PMAT to recall order)

21. PROPHASE
(FIRST)
1. Prophase – the 1st and longest phase
of mitosis during which the :
A. Chromosomes condense & become
visible.
B. Centrioles move to opposite sides of
the nucleus.
C. Nucleolus disappears.
D. Nuclear membrane breaks down.
E. Spindle (fanlike structure that helps
separate chromosomes) forms.
F. Spindle fibers attach to centromeres
of chromosomes.

22. 2. Metaphase – 2nd phase of
mitosis during which the
chromosomes line up across
the center of the cell.
(M&M : Meta = middle)
METAPHASE

23. ANAPHAS
E
3. Anaphase – 3rd phase of
mitosis during which the
centromeres split &
individual chromatids
move toward the poles.
(AAA – in ANAPHASE
chromosomes are pulled
APART & move AWAY to
opposite sides).

24. TELOPHA
SE
4. Telophase – 4th & final phase of
mitosis during which the :
A. Chromosomes uncoil into a mass
of material & can’t be seen.
B. Nuclear membrane re-forms
around each cluster of
chromosomes.
C. Spindles break apart.
D. Nucleolus becomes visible in
each daughter cell.
*Cytokinesis usually occurs at
the same time as Telophase.

25. CYTOKINESI
S
Cytokinesis – division of cytoplasm.
-In animal cells cytokinesis occurs
by drawing in the cytoplasm until it
pinches into 2 parts (cleavage
furrow).
-In plant cells cytokinesis occurs
when a structure known as the cell
plate forms midway between the
divided nuclei.
The cell plate becomes a separating
membrane & the cell wall forms in it.

26. PLANT CELL MITOSIS

27. 2 TYPES OF
CELL DIVISION

28. 1.Name the phases
starting at the top.
Mitosis

29. 2.Name the phase
3.Identify X
4.Identify Y

30. 5. Name the
phase

31. 6. Name the
phase

32. CANCER CELLS
• Result of uncontrolled cell
division of cells that have lost
ability to regulate cell cycle
• Reproduce more rapidly than
normal cells
• Masses formed called ‘tumors’