The number of chromosomes in the somatic cell of Drosophila is 8. Determine the number of chromosomes and DNA molecules in Drosophila during ovogenesis in anaphase meiosis 1 and prophase meiosis 2. Explain the results.
In somatic cells, a diploid set of chromosomes – 8 chromosomes, 8 DNA molecules.
During ovogenesis in the anaphase of meiosis I – 8 chromosomes 16 chromatids. In interphase, DNA replication (the number of DNA molecules becomes twice as many). Next, I division of meiosis is reduction, the number of chromosomes and DNA molecules at each pole of the cell in anaphase I will be half as much (homologous chromosomes diverge to the poles of the cell).
During ovogenesis in prophase II – 4 chromosomes, 8 DNA molecules. In telophase I, two haploid cells are formed, two-chromatid chromosomes (1n2c). After reduction division, DNA replication does not occur; the number of chromosomes and DNA molecules remains the same (1n2c) as in telophase I. That is, in prophase II, the set 1n2c.
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