高中教材中,介绍了两种计算遗传机率的方法,其一是棋盘法;其二是分枝法。棋盘法展示出雌雄配子的种类、比例及各种雌雄配子两两结合后的子代的总数、基因型及其比例,进而得出表现型及其比例。此方法能揭示问题本质,利于学生对分离规律、自由组合规律及结果产生一个较为直观的认识。学生对这两种规律进行认识后,解决这类问题时,该种方法自然就不合时宜,繁锁且费时。教材中又给出了另一种方法:分枝法。其优点是过程清晰便于 High school teaching materials, introduced two methods to calculate the genetic probability, one is the checkerboard method; the other is the branch method. The checkerboard method shows the types and proportions of male and female gametes, the total number of genotypes and their proportions, and the phenotypes and proportions of the male and female gametes combined with each other. This method can reveal the essence of the problem and help students to have a more intuitive understanding of the law of separation and the law of free combination. Students to understand these two laws, to solve such problems, this method is naturally outdated, cumbersome and time-consuming. The textbook gives another way: the branch method. The advantage is that the process is clear and easy