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遗传变异的实验设计是高考的重点也是难点,学生在解答这类题时总觉得会顾此失彼,难以考虑周全,现将其中三类题型的解题方法和技巧归纳如下。一、鉴别一对相对性状的显、隐性关系解题方法:此类题目解题前必须先确定具有相对性状的个体是纯合子还是杂合子,然后选择用杂交还是自交进行实验设计。(1)杂交法。具有相对性状的纯合亲本杂交,子代出现的性状就为显性性状,未出现的为隐性性状。(2)自交法。根据杂合子自交后代出现性状分离的特点判
Experimental design of genetic variation is the focus of the college entrance examination is also difficult, students always feel like they would like to take care of this kind of problem, it is difficult to consider comprehensive, now the three types of question solving methods and techniques are summarized as follows. First, the identification of a pair of relative traits significant, recessive relationship problem-solving methods: Such problems must first determine whether the individuals with relative traits homozygous or heterozygous, and then choose to use hybrid or self-designed experimental design. (1) hybridization method. The homozygous parent with the relative trait hybridized, the trait appeared in the offspring was the dominant trait, but the recessive trait did not appear. (2) self-cultivation method. According to the characteristics of segregation of hybrids selfing offspring