cell mitosis

1. Prepared by :
En. Muhd Fazli b. Dollah
SP Integrasi Gopeng

3. LEARNING OUTCOMES
• To state the necessity forthe
production ofnew cells in
organisms,
• To explain the necessity for the
production ofnewcells identical to
parent cells,
• To state the significanceof mitosis,
• To identify the phases in the cell
cycle,

4. MITOSIS
• A type of cell division which
involve the division of the
nucleus to produce two
daughter cells, each contain
same number & same kind of
chromosome as the parent cell
• Occurs in all somatic cells
except gametes.

5. • In unicellular organisms – for asexual
reproduction. (Amoeba sp.)
• Multicellular organisms – to generate new
cells to replace dead & damaged cells, for
growth & development
• Somatic cells contain 2 sets of chromosomes,
1 set from female parent, 1 set from male
parent –diploid(2n)
• Single set of unpaired chromosome –
haploid (n)
• Each somatic cells produce 2 new diploid cells
identical to the parent cell

6. Examples number of chromosomes
ORGANISM SOMATICCELL (2n) GAMETECELL (n)
Human 46 23
Camel 70 35
Goat 60 30
Porcupine 34 17
Bat 44 22
Squirrel 40 20
House fly 12 6
Chicken 78 39
Alligator 32 16
Mosquito 6 3
Pea 14 7
Rice 24 12

7. SIGNIFICANCE OF MITOSIS
• For growth, repair & replaces cells
that are dead or damaged
• A form of asexual reproduction to
increase the number of organisms
• To ensure that the offsprings/new cells
are genetically identical to the parent.
• Preserves the diploid number of
chromosomes

8. The Cell Cycle
INTERPHASE (G1, S, G2)
G1 : Growth phase 1
The cell growth by producing proteins &
cytoplasmic organelles
S : Synthesis
Synthesis of DNA, chromosomes are
duplicated & DNA has replicated to form
2 identical sister chromatids joined
together by centromere
G2 : Growth phase 2
Cell growth & cell differentiation occur
M PHASE(Cell Division)
Mitosis : nucleus divides
Cytokinesis : division of cytoplasm

10. LEARNING OUTCOMES
• To explain the process of
mitosis & cytokinesis,
• To arrange the various stages
of mitosis in the correct
sequence,
• To compare and contrast
mitosis & cytokinesis in animal
cell & plant cell

12. STAGE OF MITOSIS
• Divided into four phase :
PROPHASE,
METAPHASE, ANAPHASE
& TELOPHASE
• Nucleus divides 
cytokinesis (cytoplasm
divides)

13. PROPHASE
• Centrioles move apart to
opposite poles
• The chromosomes coil up,
condense & shorten
• Two identical chromatids (sister
chromatids) appears, attached
at centromere
• Nuclear membrane breaks down
• Nucleolus disappears
• Spindle fibres begin to form
extend between the centrioles.

14. METAPHA
SE
• The chromosomes move
to the cells equator
• The chromosomes line up
along the equator of the
cell with the
centromeres attached to
the spindle fibres
• Each chromatid of the
chromosome faces its
own pole
• Metaphase ends when
the centromeres divide

15. ANAPHASE • The centromere of each
chromosome divides into two
• The sister chromatids of each
chromosome separate and
move to opposite poles of the
cell
• The spindle fibres pull the
centromere toward each pole
with the chromatid arms
trailing behind
• When the chromatids reach
their respective poles, the
chromatids become
independent chromosomes.

16. TELOPHAS
E
• Final stage of mitosis
• Two sets of chromosomes, one
at each pole
• Chromosomes start to uncoil &
revert to their extended state.
• Less visible under the
microscope
• Spindle fibres begin to
disappear
• Nuclear membrane begin to
form around each
chromosomes. 2 daughter nuclei
are formed
• Cytokinesis occurs at the end of
telophase

17. CYTOKINESIS
• The division of cytoplasm.
• Animal cell = actin filaments in the cytoplasm
contracts to pull a ring of the plasma membrane
inwards to form a cleavage furrow  the cell is
separated into 2 daughter cells.
• Plant cell = starts with the formation of cell plate
at the equator of the cell  cell plate enlarge 
new cell wall is formed  2 daughter cells are
produced.

19. OVERALLPROCESS OF MITOSIS

20. LEARNING OUTCOMES
• To explain the importance of
controlled mitosis,
• To explain the effects of uncontrolled
mitosis in living things,
• To describe the application of
knowledge on mitosis in cloning,
• To explain the advantages &
disadvantages of cloning.

21. REGULATION
OF
THE
CELL
CYCLE
• Cell cycle is controlled by
genes of the chromosomes
• Each type of cell has its own
timing & rate of cell division
(controlled mitosis)
• Uncontrolled mitosis happen when
the genes that regulate the cell
cycle is mutated or damaged
• May be caused by too much
exposure to carcinogens (cancer-
causing agent).

22. REGULATION
OF
THE
CELL
CYCLE
• Tumor : the number of
abnormal cells produced
increase very quickly
• Benign tumor : abnormal
cells remain at the
original site
• Malignant tumor : tumor
becomes invasive & spread
to neighbouring tissues,
impairing the functions of
one or more organs 
cancer

23. APPLICATION OF KNOWLEDGE
ON MITOSIS IN CLONING
• To increase the
quantity of the product
• To improve the
quality, to produce
new species & to
ensure uniformity in
the traits of the plants

24. CLONING
• A natural process  asexual reproduction of unicellular organisms
• Contain same genetic content & chromosomal number with one another as well as
with the parent organism
• CLONING:A TECHNIQUE /
theprocessof
producingclonesor
genetically identical
organisms through
asexuallyreproduction.

26. CLONING / GENETIC
ENGINEERING
• A highly artificial form of asexual
reproduction based on mitosis
• The offspring is produced by mitosis from
a diploid cell
• The transfer of the nucleus from a somatic
cell to an ovum or embryonic cell with the
nucleus removed.

27. TISSUE CULTURE
• Atechniqueinreproduction
whichinvolvesthetransferof
tissuesorcellsfromanorganism
intoasuitableculturemedium
toproduceawholenew
organism(identicaltothe
existingorganism)clone

28. AN OUTLINEOF PLANT TISSUE CULTURE
• Sterilised apparatus & materials 
The surface of a leaf is sterilised
with ethanol / dilute sodium
hypochlorite solution  Small pieces
of tissue (explants)  culture
medium  a callus (an
undifferentiated mass of tissue)
formed (mitosis)  embryos
plantlets  transferred to
the soil  adult plants

31. ADVANTAGES
1. Produced in a short time (increase quantity)
1. The good qualities of the plants/ animals can be
selected & maintained in the clones
1. Increases the rate of production & the quality of
the product
1. Ensure the continuity of hereditary traits from
parent to the clones
1. Can be carried out any time of the year

32. DISADVANTAGES
1. The resistance of the clones towards diseases &
pests is the same. 1 infected with a
disease/pests, all the clones will also affected.
Lead to the extinction of the species.
2. Carried out under controlled environment.
External environment changes, the will be
destroyed
3. Prevents natural selection
4. No variation