一、关于生物变异基本概念的考查例1下列有关基因突变的叙述正确的是A.生物随环境改变而产生适应性变异B.由于细菌的数量多,繁殖周期短,因此,其基因突变率很高C.基因突变在自然界的物种中广泛存在D.自然状态下的突变是不定向的,而人工诱发的突变是定向的解析本题考查基因突变的 First, the examination of the basic concept of biological variation Example 1 The following description of gene mutations is correct A. Biological changes with the environment caused by adaptive mutation B. Because of the large number of bacteria, reproductive cycle is short, so its gene mutation rate is very High C. Gene mutations are widespread in species in nature D. Mutations in the natural state are untargeted, whereas artificially induced mutations are directed to the analysis of the subject’s mutations.