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1．永丰中学马光文同学问:从下面这道题的4 个选项看,都存在相同的基因数目。解答此题的关键就是染色体组数的确定,请问如何从基因组成上确定染色体组数? 例题:分析下列四种基因型属于四倍体的是 A、DdEe B、AAaa C、AaBa D、ABDE 曾老师答:由于一个染色体组内,各染色体形态、大小均不同。也就是说,不存在同源染色体,当然也就不存等位基因或相同基因。所以,细胞内形态相同的染色体有几条,则含有几个染色体组;在细胞或生物体的基因型中,同一种基因(包括同一字母的大小写)出现几次,则含有几个染色体组。此题Aaaa表示同一种基因出现4次,则含有4个染色体组．即属于四倍体的。其他选项表示同一种基因出现不是4次。这种方法只适用于同源二倍体或同源多倍体的判断。
1. At the same time, Ma Guangwen, a student at Yongfeng Middle School, asked: From the four options for the following question, there are the same number of genes. The key to answer this question is to determine the number of chromosomes. How do you determine the number of chromosomes from the genetic composition? Example: Analysis of the following four genotypes belongs to the tetraploid: A, DdEe B, AAaa C, AaBa D, ABDE Teacher A: As a result of the chromosomes, the chromosomes are different in shape and size. That is, there is no homologous chromosome, and of course there is no allele or the same gene. Therefore, if there are several chromosomes with the same morphology within the cell, there are several chromosome groups; in the genotype of cells or organisms, the same gene (including the case of the same letter) appears several times and contains several chromosome groups. . This question Aaaa indicates that the same gene appears four times and contains four chromosome groups. It is a tetraploid. Other options indicate that the same gene does not appear four times. This method is only applicable to the judgment of homodiploid or homopolyploid.