在高中“遗传变异”一章中,我们常常见到根据某家族某遗传病的系谱图来推断遗传类型的试题。这类题是高考题中的热点内容。考查的知识点主要集中在以下几方面:一是遗传类型的判定(包括致病基因显隐性的判定和致病基因存在位置的判定);二是亲代或子代表现型或基因型的确定;三是遗传病发生几率的分析及预测。而遗传类型的判定是最基本的,同时也是最重要的,现归纳判定遗传类型的基本思路:一、掌握常见的遗传类型 In the High School chapter, “Genetic Variants,” we often see questions that infer a genetic type based on a pedigree of a family genetic disease. Such questions are hot topics in the college entrance examination questions. The examination of knowledge points mainly in the following aspects: First, the determination of genetic types (including pathogenic gene recessive determination and pathogenic genes exist to determine the location); the second is the parent or child representative phenotype or genotype determination Third, the incidence of genetic disease analysis and prediction. The determination of genetic types is the most basic, but also the most important, and now conclude the basic idea of ​​genetic types: First, to master the common genetic types