This is my presentation for a biology class on Mitosis.

1. CELL DIVISION
Discussion Forum Unit 4
Mitosis: The Cell Cycle
by Solomon K. Lagat
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 1

2. CELL DIVISION
I am Solomon Lagat from Kenya,
East Africa. I work in the Kenyan
Judiciary to support delivery of
justice using ICT. I am also a
qualified Special Education
teacher and I love teaching. I
believe a teacher should be
knowledgeable and this is the
reason as to why I took this
course which is totally unrelated
to Computer Science which I am
currently pursuing. I am going to
take you through Cell Division or
Mitosis.
Enjoy the presentation!
These slides are designed by Solomon K. Lagat – Introduction to Biology Course ,Unit 4. 2

3. What is mitosis?
 Mitosis is a process in which one cell divides
into two identical daughter cells that have
similar genetic material. Mitosis occurs
mainly in somatic cells.
•Cell division occurs through a cycle
consisting of phases.
•These phases include prophase,
prometaphase, metaphase, anaphase,
telophase and cytokinesis.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 3

4. Interphase and mitosis
 Interphase is clearly not part of mitosis.
•At this stage, the cell engages
itself in metabolic activity that
prepares the cell it for mitotic
division.
•In this case, a cell gets the
idea that it is time to divide. It
has to prepare everything i.e.
duplicate DNA and get
centrioles in the right position.
After the interphase, the next phases which we are going to
explore include prophase, prometaphase, metaphase,
anaphase, telophase and cytokinesis.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 4

5. Prophase
 Chromatin in the nucleus
begins to condense and
the nucleolus disappears.
 Centrioles begin moving
to opposite ends of the
cell.
 Fibers extend from the
centromeres.
 Some fibers cross the cell
to form the mitotic spindle.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 5

6. Prometaphase
 This phase begins by
dessolution of the nuclear
membrane.
 Proteins attach
themselves to the
centromeres forming the
kinetochores.
 Microtubules then attach
themselves at the
kinetochores and the
chromosomes begin
moving.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 6

7. Metaphase
 At this phase, all of the pieces
are aligning themselves for the
big split.
 The DNA lines up along a
central axis and
the centrioles send out
specialized tubules that connect
to the DNA.
 The DNA (chromatin) has now
condensed into chromosomes.
 Two strands of
a chromosome are connected
at the center with something
called a centromere.
 The tubules actually connect to
the centromere, not the DNA.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 7

8. Anaphase
 The separation begins
where half of the
chromosomes are pulled
to one side of the cell and
the other half go the other
way.
 When the movement of
chromosomes to the other
side of the cell is
complete, marks the
beginning of telophase.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 8

9. Telophase
 This is the time when
the cell membrane closes
in and splits the cell into
two pieces.
 We will have two separate
cells each with half of the
original DNA.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 9

10. Cytokinesis
 Cytokinesis in animals
happens when a protein
fiber ring (actin) which is
situated around the center
of the cell contracts and
pinches the cell into two
daughter cells, each with
one nucleus.
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 10

11. Conclusion
Importance of mitosis:
 Mitosis is one of the important part of the growth
and development process in both animals and
plants.
 It also makes it possible for tissues to repair i.e.
healing when we get hurt.
 For this to happen, mitosis maintains the same
genetic makeup in both daughter cells.
http://www.biology.arizona.edu/cell_bio/tutorials/cell_
cycle/MitosisFlash.html
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 11

12. References
 Thomson, C. (2014). Introduction to Biology.
Course eBook. Retrieved from:
http://my.uopeople.org/mod/book/tool/print/index
.php?id=45613
 University of Arizona, (2004). The Cell Cycle &
Mitosis Tutorial, Mitosis. The Biology Project.
Retrieved from:
http://www.biology.arizona.edu/cell_bio/tutorials/
cell_cycle/cells3.html
http://www.biology.arizona.edu/cell_bio/tutorials/cell_
cycle/MitosisFlash.html
These slides are designed by Solomon K. Lagat – Introduction to Biology Course Unit 4,. 12