Question

What happens in meiosis 2?

Answer 1

Meiosis:

1. Meiosis is the process by which a single cell divides twice to produce four cells with half the original genetic information.
2. It occurs in two stages that is meiosis I and meiosis II).
3. The number of cells doubles during meiosis I, while the number of chromosomes does not.
4. As a result, each cell has half as many chromosomes.
5. The second division is meiosis II, which is similar to mitosis in that the number of chromosomes does not decrease.
6. As a result, meiosis II is a mitotic division of each haploid cell formed during meiosis I.

Phases of meiosis II :

Meiosis II has five stages: Prophase II, Metaphase II, Anaphase II, Telophase II and Cytokinesis II.

Prophase II :

1. There are two daughter cells with 23 chromosomes at the start of this stage (23 pairs of chromatids).
2. The chromosomes condense again in each of the two daughter cells, forming visible X-shaped structures that may be viewed under a microscope.
3. The membrane around the nucleus in each daughter cell breaks, allowing the chromosomes to be released. Centrioles replicate.
4. The meiotic spindle forms once more.

Metaphase II :

1. Spindle fibres develop, and sister chromatids align to the cell's equator.

Anaphase II :

1. The activity of the meiotic spindle pulls sister chromatids to opposing poles.
2. Individual chromosomes have emerged from the divided chromatids.

Telophase II & Cytokinesis II :

1. Once at the poles, the chromatids uncoil forming thin threadlike chromatin.
2. The nuclear membrane reforms into four haploids (n) daughter cells from two diploids (2n) cells.
3. When cytokinesis is complete, four granddaughter cells are formed, each with half a set of chromosomes (haploid): in men
4. These four cells are all sperm cells; in females, one of the cells is an egg cell, while the other three are polar bodies (small cells that do not develop into eggs).