There is a brief interphase stage before the start of meiosis II. The membrane then divides through citokinesis. Here each chromosome from the homologous pair are found at opposite poles and the nuclear membrane reforms around each daughter nucleus.
The cell membrane starts to prepare for its separation at the equator to form two cells. This halves the chromosome number however each chromosome is still composed of two sister chromatids. This is the stage where the homologous chromosomes are separated and pulled to opposite poles. Here the paired up homologous chromosomes line up at the equator and the spindle fibbers attach to the chromosomes in a way that ensures that for each homologous pair, one chromosome moved to one pole and the other moves to the opposite pole. The nuclear membrane also starts to break down and the spindle microtubules stretch out from each pole to the equator. Crossing over is the exchange of genetic material between non-sister chromatids. Once the homologous chromosomes are paired up, crossing over occurs. In prophase I the chromosomes pair up so that the chromosomes in each pair are homologous. The first stage of meiosis I is prophase I. (See notes on mitosis) After meiosis I there is another brief interphase stage which is followed by meiosis II. Meiotic cells have an interphase stage before the start of meiosis I which is similar to mitosis. 4.2.3 Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells. Homologous chromosomes: chromosomes with the same genes as each other, in the same sequence but do not necessarily have the same allele of those genes. Meiosis is a reduction division of a diploid nucleus to form haploid nuclei. Meiosis 4.2.1 State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei.
In the latter part of interphase, the cell still has nucleoli present.Note that the G in G2 represents gap and the 2 represents second, so the G2 phase is the second gap phase. The cell synthesizes proteins and continues to increase in size. G2 phase: The period after DNA synthesis has occurred but prior to the start of prophase.In most cells, there is a narrow window of time during which DNA is synthesized. S phase: The period during which DNA is synthesized.Note that the G in G1 represents gap and the 1 represents first, so the G1 phase is the first gap phase. In this phase, the cell increases in mass in preparation for cell division. G1 phase: The period prior to the synthesis of DNA.At the end of the meiotic process, four daughter cells are produced. Before a dividing cell enters meiosis, it undergoes a period of growth called interphase. There are two stages or phases of meiosis: meiosis I and meiosis II.
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