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1.减数分裂异常的时期与原因减数分裂是进行有性生殖的生物在形成生殖细胞(配子)的过程中特有的细胞分裂方式,正常的分裂结果是新产生的生殖细胞中的染色体数目比体细胞减少一半.对减数分裂异常的时期与原因分析如下:(1)异常时期:1在减数第一次分裂后期有同源染色体没有分开而同时进入一个次级性母细胞,结果一个次级性母细胞的染色体多,另一个次级性母细胞的染色体少;2在减数第二次分裂后期姐妹染色
1. Periods and causes of meiosis abnormalities Meiosis is the cell division pattern unique to sexual reproduction organisms in the process of forming germ cells (gametes). The normal division result is the number of chromosomes in newly generated germ cells Compared with the somatic cells in half.Analyzing the period and reason of meiotic abnormalities are as follows: (1) Abnormal period: 1 in the first division after the first homologous chromosomes are not separated but at the same time into a secondary blast cell, the results One secondary blast cell had more chromosomes and the other secondary blast cell had fewer chromosomes; 2 Sister staining at the second stage of meiosis