在遗传学的教学中 ,由子代表现型及其比例推断亲代基因型是一种常见题型。学生对这类题往往不知从什么地方入手 ,有时甚至把亲代可能出现的类型一一列出来 ,再通过各种类型的杂交 ,以它们产生子代的表现型及其比例和已知子代表现型及其比例对照 ,最后确定亲代的基因型。这种办 In genetics teaching, it is a common question to infer parental genotypes from subtypes and their proportions. Students often do not know where to start these types of questions, and sometimes even list the possible types of parents, and then through various types of cross-breeding, so that they produce offspring phenotypes and their proportions and known sub-representatives. In comparison with its proportion, the parental genotype was finally determined. This kind of office