The chromosome set of somatic cells of the green frog is 26. Determine the chromosome set and the number of DNA molecules in one of the germ cells in the prophase of meiosis I, in the meta-phase of meiosis I and anaphase of meiosis II. Explain what processes occur during these periods and how they affect the change in the number of DNA and chromosomes.
1) in the prophase of meiosis I the number of DNA molecules is 52, since they are doubled in the interphase (before division), and the number of chromosomes does not change – there are 26;
2) in the metaphase of meiosis I, the number of DNA molecules is 52, the number of chromosomes is 26, the chromosomes are located at the equator of the cell;
3) in the anaphase of meiosis II, the number of DNA molecules – 13, chromosomes – 13 (at each cell pole), sister chromatids – chromosomes – diverge to the cell poles, since after the reduction division of meiosis I the number of chromosomes and DNA decreased by 2 times.
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