During metaphase II, the centromeres of the paired chromatids align along the equatorial plate in both cells. Then in anaphase II, the chromosomes separate at the centromeres. The spindle fibers pull the separated chromosomes toward each pole of the cell. Finally, during telophase II, the chromosomes are enclosed in nuclear membranes.
Cytokinesis follows, dividing the cytoplasm of the two cells. At the conclusion of meiosis, there are four haploid daughter cells that go on to develop into either sperm or egg cells. Further Exploration Concept Links for further exploration cell division replication metaphase anaphase telophase linkage chromosome cytokinesis haploid prometaphase principle of segregation principle of independent assortment spindle fibers gamete DNA chromatin nucleus cytoplasm eukaryote prophase recombination principle of segregation Principles of Inheritance.
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Change LearnCast Settings. Scitable Chat. Instead the starting cell can be any undifferentiated diploid cell that finds itself in the appropriate location e. Then it divides, each daughter cell receives two copies of each chromosome and is again 2n.
In meiosis a diploid cell 2n replicates its DNA so that it now has four copies of each chromosome. Then each of these divides once more without replicating DNA so that there are now four cells each with one copy of each chromosome 1n. You might be tempted to think of a diploid cell which has replicated its DNA as tetraploid, but this word is not normally used in this context, since this is a transient 4n state.
This is a very broad overview. Have a look at the Wikipedia entry for meiosis to get a more detailed view and extended terminology. Primary spermatocytes and primary oocytes are both diploid cells which undergo DNA replication before entering meiosis I. Meiosis starts with a somatic diploid cell.
To make a long story very, very short, this one cell undergoes cytokinesis twice. You end up with four haploid cells, called gametes or sex cells. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? The meiotic spindle, consisting of microtubules and other proteins, extends across the cell between the centrioles.
Metaphase I: The chromosome pairs line up next to each other along the centre equator of the cell. The centrioles are now at opposites poles of the cell with the meiotic spindles extending from them. The meiotic spindle fibres attach to one chromosome of each pair. Anaphase I: The pair of chromosomes are then pulled apart by the meiotic spindle, which pulls one chromosome to one pole of the cell and the other chromosome to the opposite pole.
In meiosis I the sister chromatids stay together. This is different to what happens in mitosis and meiosis II. Telophase I and cytokinesis: The chromosomes complete their move to the opposite poles of the cell.
At each pole of the cell a full set of chromosomes gather together. A membrane forms around each set of chromosomes to create two new nuclei. The single cell then pinches in the middle to form two separate daughter cells each containing a full set of chromosomes within a nucleus. This process is known as cytokinesis. Meiosis II 6. Prophase II: Now there are two daughter cells, each with 23 chromosomes 23 pairs of chromatids. In each of the two daughter cells the chromosomes condense again into visible X-shaped structures that can be easily seen under a microscope.
The membrane around the nucleus in each daughter cell dissolves away releasing the chromosomes. The centrioles duplicate. The meiotic spindle forms again. Metaphase II: In each of the two daughter cells the chromosomes pair of sister chromatids line up end-to-end along the equator of the cell. The centrioles are now at opposites poles in each of the daughter cells. Meiotic spindle fibres at each pole of the cell attach to each of the sister chromatids. Anaphase II: The sister chromatids are then pulled to opposite poles due to the action of the meiotic spindle.
The separated chromatids are now individual chromosomes. Telophase II and cytokinesis: The chromosomes complete their move to the opposite poles of the cell.
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