Cell division occurs through mitosis and meiosis. Mitosis produces two identical daughter cells from a single parent cell, maintaining chromosome number. Meiosis produces four haploid cells from one diploid cell, reducing chromosome number by half. The document outlines the stages and key differences between mitosis and meiosis, including that meiosis involves two rounds of division separated by DNA replication and produces genetic variation through independent assortment and crossing over.

1. CELL CYCLE & DIVISION
ABHISHEK SINGH
DEPARTMENT OF PLANT BREEDING AND GENETICS

2. INTRODUCTION
PRESENTATION
TITLE
2
Cell is the structural and functional unit if
cell in almost all the living organisms and
all the cells originate through division of
pre-existing cells.

3. FUNCTION OF CELL DIVISION
 MAIN FUNCTION IS TO PRODUCE DAUGHTER CELL FROM A SINGLE PARENT
CELL.
 CELL DIVISION KEEPS THE SIZE OF CELLS WITHIN A LIMITED RANGE.
 A LARGE CELL IS MORE LIKELY TO DAMAGE THAN A SMALLER CELL. IN
VIEW OF THESE CELL DIVISION EVOLVED AND DEVELOPED VERY EARLY IN
ORGANIC EVOLUTION.
 CELL DIVISION IS THE PRE REQUISITE FOR THE CONTINUITY OF LIFE AND
FOR THE EVOLUTION OF VARIES LIFE FORMS.

4. MITOSIS
PRESENTATION
TITLE
4
IT IS THE CELL-DIVISION
PROCESS THAT PRODUCES
TWO GENETICALLY
IDENTICAL DAUGHTER
CELLS FROM A SINGLE
ORIGINAL PARENTAL CELL,
IS AMONG THE MOST
FUNDAMENTAL AND
IMPORTANT PROCESSES

5. THE CELL CYCLE IS DIVIDED INTO
INTERPHASE AND M PHASE
PRESENTATION
TITLE
5
Interphase
Prophase
Metaphase
Anapahse
Telophase

6. PRESENTATION
TITLE
6
INTERPHASE
G1 Phase: Active
gene expression &
cell activity and RNA,
protein synthesis
grows maxiumum
S Phase: DNA
replication, histone
protein synthesis and
centriole formation
(Animal cell)
G2 Phase:
Preparation for cell
division and tublin
protein formation
(Plant cell)

7. PLANTS.
CYTOKINESIS – THE SEPARATION OF A CELL OR SEPARATION OF
CYTOPLASM IS KNOWN AS THE CYTOKINESIS.
2. KARYOKINESIS – SEPARATION OF DAUGHTER CELL.
3. FOR PLANT – CELL PLATE FORMATION WITH THE HELP OF
PHRAGMOPLAST. GOLGI VESICLE FUSES AND FORM CELL PLATE IN THE
CENTRIFUGAL ORDER.
4. FOR ANIMAL CELL – ANNULAR RING FORMATION TAKES PLACE
TOWARDS CENTER I.E., CENTRIPETAL ORDER.
5. THE MOST ACTIVE PHASE OF CELL CYCLE IS INTERPHASE
6. GO PHASE – DO NOT DIVIDE FURTHER EXIT G1 AND NO PROLIFERATE
UNTIL CALLED TO DO SO.
7. CYCLE IS RUNNING – CYCLIN AND CDKS.
PRESENTATION
TITLE
7

8. MAJOR EVENTS OF MITOSIS
PRESENTATION
TITLE
8

9. MISC. POINTS
PRESENTATION
TITLE
9
 Nucleolus disappear and distributed in chromosome.
 Nuclear membrane disappear and distributed in endoplasmic reticulum.
 ANIMAL Cell – Spindle apparatus is organized before nuclear membrane disappear.
 PLANT Cell – Spindle apparatus is organized after nuclear membrane disappear.
 Endomitosis – Cell division occur but cytokinesis not occur. It is cause polyploidy.
 Endoreduplication – DNA replication occur but cell division do not occur. It cause
polytene chromosome.
ADVANTAGES OF MITOSIS
1. Responsible for growth and development.
2. The number of chromosome remains the same in all the cells produced by this division.
3. Daughter cells produced are identical to the parent cell.
4. Equational cell division.

10. MEIOSIS
PRESENTATION
TITLE
1 0
MEIOTIC DIVISION OF A
SOMATIC CELLS (2N)
GIVE RISE TO FOUR
HAPLOID (N) CELLS. THE
REDUCTION DIVISIONS
IN CHROMOSOME
NUMBER MAINLY DUE
TO SINGLE S PHASE
FOLLOWED BY TWO
SUCCESSIVE NUCLEAR

11. IMPORTANT
TERMS
PRESENTATION
TITLE
11
 BIVALENT – Refers to paired homologous chromosome in
pachytene stage. Also called as tetrad
 SYNAPSIS – Refers to the joining of non-sister chromatids of
homologous chromosome at a point.
 ASYNAPSIS – Fail to join.
 DESYNAPSIS – Fail to separate.
 CHIASMA – During diplotene stage, two homologous
chromosomes attached with each other at many points known as
chiasma. Actually, it is the point at which crossing over had taken
place along the homologous chromosome pair.
 CHIASMA TERMINILIZATION – During diplotene stage, two
homologous chromosome will move away from each as a result
of which the chiasma will move towards ends of the chromosome,
the process is known as chiasma terminalisation.
 C VALUE – Refers to the amount of DNA present in haploid
genome of an organisms.
• MEIOSIS I – Reductional division/Heterotypic division
• MEIOSIS II – Equational division/Homotypic division

12. STAGES OF MEOISIS
PRESENTATION
TITLE
1 2

13. STAGES OF MEOISIS
PRESENTATION
TITLE
1 3

14. STAGES OF MEOISIS
PRESENTATION
TITLE
1 4

15. STAGES OF MEOISIS
PRESENTATION
TITLE
1 5

16. AREAS OF FOCUS
PRESENTATION
TITLE
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PHENOMEN
AS
SUB-STAGE
OF
PROPHASE
I
Bouquet
stage
Leptoene
Synapsis Zygotene
Crossing
over
Pachytene
Scientist Discoveries/Term
s
Flemming Term Mitosis
(1882)
Former & Moore Term Meiosis
(1883)
Von Baneden Describe Meosis
in roundoworm
Moses Synatonemnal
complex
Hertiwig Kern plasma
theory
Bajer, Nicklas Metakinesis

17. SUMMARY
PRESENTATION
TITLE
1 7
• Mitosis and meiosis differ in the behavior of chromosomes in metaphase and
anaphase. In metaphase I of meiosis, homologous pairs of chromosomes line up
on the metaphase plate
• Whereas individual chromosomes line up on the metaphase plate in metaphase of
mitosis (and metaphase II of meiosis).
• In anaphase I of meiosis, paired chromosomes separate, and each of the
chromosomes that migrate toward a pole possesses two chromatids attached at
the centromere.
• In contrast, in anaphase of mitosis (and anaphase II of meiosis), chromatids
separate, and each chromosome that moves toward a spindle pole consists of a
single chromatid.

18. THANK YOU