关于自由组合规律的遗传学图解法,常见的有“棋盘式”图解法和“分枝法”。我们在教学实践中还创造了一种“分离组合式”图解法。这三种方法,运用时,各有所长。中学课本上和一般遗传学书上常的用图解方法,是一种入门的基础方法。其优点是细致、规范、严密,有利于理解自由组合规律。但在运用中需要作出大小三角形的归类,则对F_2中四种表现型、九种基因型和十六种配子组合方式就能一目了然。其不足之处,是要将不同种的雌、 About the law of free combination of genetic mapping method, the common “checkerboard” graphic method and “branching method.” We have also created a “separate combination” graphic method in teaching practice. These three methods, use, each has its own merits. High school textbooks and general genetics book often used graphic method is a basic method of getting started. Its advantages are meticulous, normative, strict, conducive to understanding the law of free combination. However, in the application of the need to make the classification of the size of the triangle, then F_2 in the four phenotypes, nine genotypes and sixteen kinds of gametes combinations can be clear at a glance. The disadvantage is that different types of female,