The document summarizes the cell cycle and its key phases. It describes the stages of mitosis including prophase, metaphase, anaphase and telophase. It also discusses the different types of cell division including cytokinesis and the three categories of cells: undifferentiated, semi-differentiated, and differentiated.

2. Dr.Hewa Balisane
2011

3. Cell cycle is the well-
order sequence of
events that makes up
the intervals between
one cell generation
and the next.
It consists of several
phases:-
(G1-phase,S-phase,G2-
phase,M-phase)

4. • Interphase
– G1= Preparation for
replication of DNA,
and protein synthesis.
– S=DNA replication
– G2=Preparation of
mitosis
• M=Mitosis
• C-phase= cytokinesis.

5. It is called resting
phase, it is the
stage between
ending and
starting of cell
division,
include(G1,S,G2
phases).

6. This type of division occurs
in somatic cell and
divided into
4stages( Prophase,
Metaphase, Anaphase,
Telophase).

7. • Centrioles move to opposite poles.
• Chromatins condense to
chromosome & chromosomes
become visible.
• Nucleolus and nuclear envelope
disappear.
• Spindle forms.
• Centrioles begin to separate, each
forming around itself a system of
microtubule called Aster.

8. • Chromosomes arrange
themselves in
equatorial plane of the
cell to form metaphase
plate.
• Microtubules of the
spindle fiber become
attached to each
chromosome in
centromere.

9. • Centromeres divide;
chromates separate and
move to opposite poles.
• Each chromosome now has its
own centromere and is called
(daughter chromosome)
• The daughter chromosome
begin to separate and move
toward opposite poles of the
cell, their centromere pointed
toward the pole

10. • Nucleolus & nuclear envelope
reappear around each group
of chromosomes.
• Chromosomes unwind & loss
their condensed structure and
become network of chromatin
material.
• Spindles disappear.
• Soon the two daughter cells
are separates (cytokinesis).

11. The process by
which the
cytoplasm divides
and one cell
becomes two
individual cells. The
process is different
in plant and
animals.

12. • Undifferentiated cell(divided
cell)
• Semi-differentiated cells: Cells
lost their ability to divide but
under certain condition return
their ability to divide(lymphatic
cells).
• Differentiated cells: They never
divide like nerve cell