Mitosis and Meiosis Stages, Structure and Difference

1. GPB-121
Department of Agriculture Botany
“Fundamentals of Genetics”
Mitosis and Meiosis Stages, Structure and Difference

2.  It is a type of cell division for somatic cells and for the asexual reproduction of
unicellular eukaryotic cells.
Mitosis is a process of nuclear division in eukaryotic cells that occurs when a
parent cell divides to produce two identical daughter cells.
 Interphase ==> Prophase ==> Metaphase ==> Anaphase ==> Telophase
==> Cytokinesis
 Discover by – Flemming (1882)
What is Mitosis ?
 Cell division in which one parent
cell (2n) is undergoes division into
two daughter cell (n).

3.  INTRAPHAS (More growth occurs)
 Resting stage (Seen under – Light microscope).
 24 hrs. Cell under goes mitosis (Long phase).
 Divided into three phases
Intra-Phase
C) Gap phase 2 (G2)
 2nd gap
 Condense RNA and Protein Synthesis.
Mitosis
A) Gap phase 1 (G1)- Major growth occurs.
 1st gap
 Synthesis of Protein and RNA (30-40%).
B) Synthesis phase (S)-
 Phase between G1 and G2 Phase.
 DNA Synthesis (2 sister chromatids produce).

4. Mitosis Stages

5.  PROPHAS (Nucleolus is imp)
 Chromosome pair up.
 Nucleolus and nucleolus membrane dispersed
(Breakdown).
 Two chromatids seen.
 At end of prophase the Thread like occurs.
 Chromosome are short and thick.
 METAPHAS
(long stage about 20 min. required)
 Chromosome pair up.
 Nucleolus and nucleolus membrane
dispersed (Breakdown).
 Two chromatids seen.
 At end of prophase the Thread like occurs.
 Chromosome are short and thick.
 Metakineis – Movement of Chromosome

6.  ANAPHAS (Shortest Phase)
 Smallest form of Mitosis.
 Two poles are shows i.e. S-N Poles.
 TELOPHAS (now there are two)
 Chromosome are coil.
 Spindle fibers are dispersed and nucleus
membrane are formed.
 Nucleus and nucleus membrane get reorganized.
 Cytokinesis
 Complete end of Telophase

8.  It is the type of cell division for the production of gametes in sexual reproduction.
 It reduces the number of chromosomes in the parent cell by half and produces four
gamete cells.
 One parent cell (2n) under goes divided into four daughter (n) cell.
 The process results in four daughter cells that are haploid, which means they
contain half the number of chromosomes of the diploid parent cell.
 1st division is – Meiotic 2 division
 2nd division is- Mitotic
 Discover by – Farmer and Moore (1905).
What is Meiosis ?

10. Meiosis
Meiosis I – Reduction division Meiosis II – Equation division
1. Intra-phase I
2. Pro-phase I
3. Meta-phase I
4. Ana-phase I
5. Telo-phase I
6. Cytokinesis I
1. Intra-phase II
2. Pro-phase II
3. Meta-phase II
4. Ana-phase II
5. Telo-phase II
6. Cytokinesis II
1. Intra-phase I
 G1 Phase- Protein and RNA synthesis
 S phase – 0.03 % DNA Present, DNA replicate Zyogtene
 G2 phase – Entry of cell depend upon S- Phase.

11. 1. Leptotene – Chromosomes are visible under light microscope.
 Condensation of chromosomes takes place.
2. Zygotene – Pairing of homologous chromosomes takes place i.e synapsis
occurs .
 0.03% DNA replication, Z-DNA synthesis.
3. Pachytene – Synapsis is completed/ End of Synapsis.
4. Diplotene –The separation of homologous chromosomes i.e. Bivalent.
5. Diakinesis – chiasma formation.
2. Pro-phase I (longest phase)
 Time required - 5 days to 5 hrs.

15. Difference

17. Similarities