It explains about what is cell division, types of cell division, why, how, functions, direct division, interphase, mitosis 4 phases - prophase, metaphase, anaphase and telophase.

1. CELL DIVISION - PART -1
DR. C. BEULAH JAYARANI
M.Sc., M.A, M.Ed, M.Phil (Edn), M.Phil (ZOO), NET, Ph.D
ASST. PROFESSOR,
LOYOLA COLLEGE OF EDUCATION, CHENNAI - 34

2. CELL DIVISION
A Parent cells
divides into two
daughter cells is
called CELL
DIVISION or CELL
REPRODUCTION.

3. WhAT IS CELL DIVISION mEANS?
Cell division is the process in
which a parent cell divides,
giving rise to two or more
daughter cells.
 It is an essential biological
process in many organisms. It is
the means used by multicellular
organisms in order to grow,
replenish (repair), and
reproduce

4. Why IS A CELL DIVISION?
Cells divide for many reasons. For
example, when you skin your
knee, cells divide to replace old, dead,
or damaged cells.
Cells also divide so living things can
grow. ... Organisms grow
because cells are dividing to produce
more and more cells.

5. TyPES OF CELL DIVISION
The three types of cell division
that occur in animal cells are :
1. MITOSIS - Indirect Division
2. MEIOSIS - Reduction Division
3. AMITOSIS - Direct Division

6. WhAT ARE ThE FuNCTIONS OF CELL DIVISION?
Cellular division has three
main functions:
(1) the reproduction of an entire
unicellular organism,
(2) the growth and repair of
tissues in multicellular animals,
and
(3) the formation of gametes
(eggs and sperm) for sexual
reproduction in multicellular
animals.

7. WhAT IS DIRECT CELL
DIVISION?
Amitosis is the direct cell
division. It is the simplest type
of cell division in which there is
no spindle formation or
condensation of fibers. Nucleus
is directly divided into two, e.g.,
bacteria

8. WhAT IS CELL CyCLE?
 A cell cycle is a series of
events that takes place in a
cell as it grows and divides.
 A cell spends most of its time
in what is called interphase,
and during this time it grows,
replicates its chromosomes,
and prepares for cell
division.

9. WhAT IS CELL CyCLE?
The G1 stage stands for "GAP 1".
The S stage stands
for "Synthesis". This is the stage
when DNA replication occurs.
The G2 stage stands for "GAP 2".
The M stage stands for "mitosis",
and is when nuclear (chromosomes
separate) and cytoplasmic
(cytokinesis) division occur.

10. INTER PHASE
Resting Phase
Interval
Prepares for
the next division -
G1 phase (cell growth), followed
by S phase (DNA synthesis),
followed by G2 phase (cell
growth).

11. mITOSIS
Fleming in 1879
Equational Division

12. PROCESS OF mITOSIS
 Consists of two events,
they are
1. Karyokinesis
2. Cytokinesis
The process by which the
nucleus of the parent cell divides
into two daughter nuclei is known
as karyokinesis.
The process by which the cytoplasm
of the parent cell, divides into two
daughter cells is known
as cytokinesis

13. PROCESS OF mITOSIS
 Karyokinesis consist of four phases, they are
Karyokinesis
PROPHASE
METAPHASE ANAPHASE TELOPHASE

14. PROPhASE
Short and thick
Centrosome splits
Spindle fibres
Nuclear membrane
and Nucleolus

15. mETAPhASE
Equatorial plane
Attached with spindle
fibre by centromere
The centromere of each
chromosomes divides into two,
each associated with a
chromatid.

16. ANAPhASE Separate and
migrate
Contraction of
spindle fibres

17. TELOPhASE
Becomes Chromatin
threads
Spindle fibres
disappear
Nuclear membrane
and Nucleolus reappear.

18. DO yOu KNOW ????
Cells of the
eye lens , nerve
cells of cerebral
cortex and most
muscle cells last
a life time but
once dead are
not replaced.

19. Nerve cells do
not undergo cell
division due to the
absence of
centrioles ,but they
are developed from
glial cells.
DO yOu KNOW ????

20. REFERENCE
“SCIENCE READER”
Tamil Nadu text book
NCERT Books
Google Images