Presentation on cell division - Akib Sumon

1. Changes in Chromosomal
Morphology During
Mitotic Cell Division
Presented by….
Akib Sumon

2. Chromosome
• A thread-like structure of nucleic acids and protein found in
the nucleus of most living cells, carrying genetic information
in the form of genes.

3. Cell Division
• The division of a cell
into two daughter cells
with the same genetic
material
• Process by which
a parent cell
divides into two
or more daughter
cells

4. Types of Cell Division
• Prokaryotic Cell Division
• After replicating its genetic material, the
parent cell divides into two equal sized
daughter cells.
BinaryFission

5. Cont’d
• Eukaryotic Cell Division

6. Chromosomal Changes………
• Divided into four phase-
Metaphase
AnaphaseTelophase

7. Prophase
The longest phase
Takes about 80 percent
of the time
First phase

8. Cont’d
• The nuclear membrane
begins to disappear
• The chromosome
become visible under
microscope
• They become short
thick and paired up

9. Cont’d
• Supercoiling of chromosome
• Special structure called kinetochores
developed on the centromere
• Spindle begins to form
• The chromosomes are thrown into agitate
motion due to the interactions of their
kinetochore fibers with other components of
the spindle.

10. Cont’d
• Microscopic view of Prophase

11. Metaphase
• Meta means middle
• The second phase
• Lasts only a few minutes

12. Cont’d
• The chromosomes
are at their most
condensed state
• The chromosome
line up across the
center of the cell
• Each chromosome
is connected to a
spindle fiber of its
centromere

13. Cont’d
• The spindle fully
develops
• Chromosome align at
metaphase plate
• Sister chromatids line
up in center of spindle
fibers
• Spindle fibers are
attached to the
chromosomes

14. Cont’d
• Microscopic view of Metaphase

15. Anaphase
• The third phase
• Also lasts a longer time
Sisterchromatid

16. Cont’d
• The chromosomes are pulled apart
• Chromosomes can be seen moving, they take on a
rough V shape
• Chromatids are called chromosomes after the
separation
• Each chromatid is considered a full fledged
chromosomes
• The once joined sisters begin to move towards
opposite poles of the cell
• Sister chromatids are separated at centromeres
• Chromosomes separate into two genetically identical
group

17. Cont’d
• Chromosomes use spindle fiber as tracks
• Polar microtubules push the poles apart
• Ends when chromosomes have arrived to the
poles
• The two poles of the cells have equivalent & a
complete collection of chromosomes
• Result of anaphase is an equal separation &
distribution of chromosomes

18. Cont’d
• Microscopic view of Anaphase

19. Telophase
• The last phase
• Results in cytokynesis

20. Cont’d
• The chromosome reach
the opposite poles of the
cells &begin to lengthen
• The spindle fibers
dissolve & a nuclear
membrane form
• Chromatin becomes
diffuse

21. Cont’d
• The nuclear envelope is
reforming
• The cytoplasm may be
dividing
• The telophase is followed
by cytokinesis
• Mitosis is complete end of
telophase

22. Cont’d
• Microscopic view of Telophase

23. Thank You To All