正确寻找连接两个变量间的全部通径链,在动物遗传育种工作中有着重要意义。本人在教学实践中,针对同学在寻找连接两个变量间通径链时容易重复的问题,摸索出了如何避免重复的方法。其方法如下: 在寻找连接两个变量间的通径链时,如果通径链在退的过程中通过了某一共同原因,那么在进的过程中就不能再通过它;反之,如果通径链在退的过程中未通过该共同原因,那么 Properly finding all the pathways linking the two variables is of great significance in the work of animal genetic breeding. In my teaching practice, I tried to find out how to avoid duplication when I was looking for a problem that was easy to be repeated when I connected the two pathways between two variables. The method is as follows: When looking for the path chain connecting two variables, if the path chain passes some common reason in the process of withdrawing, it can not pass it in the process of entering. On the contrary, if the path The chain did not pass this common cause in the process of withdrawal, then