Meiosis II
Prophase II. Meiosis II is initiated immediately after cytokinesis, usually before the chromosomes have fully elongated. In contrast to meiosis I, meiosis II resembles a normal mitosis. The nuclear membrane disappears by the end of prophase II. The chromosomes again become compact

Metaphase II. At this stage the chromosomes align at the equator and the microtubules from opposite poles of the spindle get attached to the kinetochores of sister chromatids.
Anaphase II. It begins with the simultaneous splitting of the centromere of each chromosome (which was holding the sister chromatids together), allowing them to move toward opposite poles of the cell
Telophase II. Meiosis ends with telophase II, in which the two groups of chromosomes once again get enclosed by a nuclear envelope; cytokinesis follows resulting in the formation of tetrad of cells i.e., four haploid daughter cells

Prophase I. Prophase of the first meiotic division is typically longer and more complex when compared to prophase of mitosis. It has been further subdivided into the following five phases based on chromosomal behaviour:
1.Leptotene
2.Zygotene
3.Pachytene
4.Diplotene and
5.Diakinesis.
Leptotene. During leptotene stage the chromosomes become gradually visible under the light microscope. The compaction of chromosomes continues throughout leptotene.
Zygotene:
1.During this stage chromosomes start parrrng together and this process of association is called synapsis. Such paired chromosomes are called homologous chromosomes.
2.Electron micrographs of this stage indicate that chromo some synapsis is accompanied by the formation of complex structure called synaptonemal complex.
3.The complex formed by a pair of synapsed homologous chromosomes is called a bivalent or a tetrad.
4.However, these are more clearly visible at the next stage. The first two stages of prophase I are relatively short-lived compared to the next stage that is pachytene
Pachytene:
During this stage bivalent chromosomes now clearly appear as tetrads.
1.This stage is characterised by the appearance of recombination nodules, the sites at which crossing over occurs between non-sister chromatids of the homologous chromosomes.
2.Crossing over is the exchange of genetic material between two homologous chromosomes. Crossing over is also an enzyme-mediated process and the enzyme involved is called recombinase.
3.Crossing over leads to recombination of genetic material on the two  chromosomes.
4.Recombination between homologous chromosomes is completed by the end of pachytene, leaving the chromosomes linked at the sites of crossing over.
Diplotene. The beginning of diplotene is recognised by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other except at the sites of crossovers. These X-shaped structures, are called chiasmata. In oocytes of some vertebrates, diplotene can last for months or years.
Diakinesis. The final stage of meiotic prophase I is diakinesis. This is marked by terminalisation of chiasmata. During this phase the chromosomes are fully condensed and the meiotic spindle is assembled to prepare the homologous chromosomes for separation. By the end of diakinesis, the nucleolus disappears and the nuclear envelope also breaks down. Diakinesis represents transition to metaphase.
Difference between prophase I and prophase II. During prophase I recombination of genes takes place, while in prophase II no such event happens. Prophase I is longer and more complicated compared to prophase II

Mitosis is divided into the following four stages
Prophase
1.Prophase is marked by the initiation of condensation of chromosomal material. The chromosomal material becomes untangled during the process of chromatin condensation.
2.The centriole, which had undergone duplication during S phase of interphase, now begins to move towards opposite poles of the cell.
3.Cells at the end of prophase, when viewed under the microscope, do not show golgi complexes, endoplasmic reticulum, nucleolus and the nuclear envelope

Metaphase
1.The metaphase is characterised by all the chromosomes coming to lie at the equator.
2.One chromatid of each chromosome connected by its kinetochore to spindle fibres from one pole and its sister chromatid connected by its kinetochore to spindle fibres from the opposite pole.
3.The plane of alignment of the chromosomes at metaphase is referred to as the metaphase plate
Anaphase
1.At the onset of anaphase, each chromosome arranged at the metaphase plate is split simultaneously and make the two daughter chromatids.
2.They are now referred to as chromosomes of the future daughter nuclei, and begin their migration towards the two opposite poles.,
3. As each chromosome moves away from the equatorial plate, the centromere of each chromosome is towards the pole and hence at the leading edge, with the arms of the chromosome trailing behind.
Telophase
This is the stage which shows the following key events:
1.Chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements.
2.Nuclear envelope assembles around the chromosome clusters.
3.Nucleolus, golgi complex and ER reform.
Cytokinesis
Mitosis accomplishes not only the segregation of duplicated chromosomes into daughter nuclei (karyokinesis), but the cell itself is divided into two daughter cells by a separate process called cytokinesis at the end of which cell division is complete.

There are two distinct type of cell divisions taking place in multicellular organisms One is mitosis in somatic cells for growth and healing of wounds and the other is meiosis in reproductive cells for producing gametes having half the number of chromosomes. It is essential to maintain the characters of the species.
More number of cells are produced in meiosis. Each division of mitosis results in the formation of two cells while in meiosis four cells are formed.

A pair of homologous chromosomes is genetically different because in a set of homologous chromosomes, one of the chromosomes belongs to the male parent and the other comes from the female parent. Therefore, one of a pair will contain paternal genes and the other will contain maternal genes. However, a pair of sister chromatids are formed from the replication of DNA during the 'S' phase of interphase. DNA replication ensures that the DNA content is doubled with identical genes being copied from the original DNA. Therefore, there is no genetic variation because there is no exchange of genetic material sister chromatids.
If crossing over occurs, then it would be possible for some genes to be exchanged between the chromatids of homologous chromosomes that have chiasmata, thus leading to genetic variation.

All these happen in the two haploid nuclei simultaneously.
(i) Prophase-II, takes short time. Spindle formation begins and the chromosomes become short. Two chromatids are joined to a single centromere. Nuclear membrane and nucleous disintegrate.
(ii) Metaphase-II At the equator, the chromosomes align at the equator and spindle is formed. The centromere of every chromosome is joined to the spindle fibre and centromere also divides.
(iii) Anaphase-II The daughter chromosomes are formed. Chromatids move towards their poles with the spindle fibres.
(iv) Telophase-II Reaching at the poles, chromosomes form nuclei which are haploid(n) daughter nuclei. Again nuclear membrane is constructed. Nucleous now becomes clearly visible.
Cytokinesis Occurs and four daughter cells are formed which are haploid (n). It may occur once or twice or only after the meiosis-II cell division.

Two phases of meiotic division: 
(i) Meiotic cell division is divided into two phases Meiosis I and Meiosis II. 
(ii) In the meiotic I division, the homologous chromosomes pair to form bivalents. Exchange of genetic material takes place. 
(iii) The chromosomes now separate and get distributed into daughter cells. 
(iv) Prophase I is divided into five sub-stages : Leptotene, Zygotene, Pachytene, Diplotene and Diakinesis. 
(v) During Metaphase I, the bivalents get arranged on equatorial plate with their arms on the plate but the centromere is directed towards opposite pole. It is followed by Anaphase I.



Fig. Stages of meiosis
(vi) Now the homologous chromosomes repel each other, and move to the opposite poles with both their chromatids. 
(vii) In this way each pole gets half the chromosomes number of the parent cell. 
(viii) In telophase I, the nuclear envelope and nucleolus again appear. Meiosis II is quite similar to mitosis. 
(ix) The centromere of each chromosome breaks, separating the chromatids, one each to a daughter cell.
(x) The meiotic cell division maintains the chromosome number of a species. 
(xi) As a result of meiotic division, the four daughter cells are formed with half the chromosome number (haploid) in each cell.

Cell division is significant in the following ways
(i) Cell multiplication Cell division is a means of cell multiplication or formation of new cells from pre-existing cells.
(ii) Continuity It maintains continuity of living matter generation after generation.
(iii) Multicellular organisms The body of a multicellular organism is formed of innumerable cells. They are formed by repeated divisions of a single cell or zygote. As the number of cells increases, many of them begin to differentiate, form tissues and organisms.
(iv) Cell size Cell division helps in maintenance of a particular cell size which is essential for efficiency and control of cell activities.
(v) Genetic similarity The common type of cell division or mitosis maintains genetic similarity of all the cells in an individual despite being different, i.e., structurally and functionally.

Neuron cells lack a centrosome and hence they do not undergo the process of cell division. Neurons lack mitotic activity. Besides centrosomes, all other cell organelles are present in neurons.