sterility and mutant

例句：

1. 1. The male mouse is sterile, so he cannot reproduce.
   这只雄性老鼠不育，所以不能繁殖。
2. 2.In some species, infertility can be caused by genetic defects.
   在一些物种中，不育可能是由遗传缺陷引起的。
3. 3. Sterility is a condition that prevents the production of offspring.
   不育是一种阻止产生后代的状况。
4. 1. Mutants are often used to study the effects of mutations on growth and development.
   突变体常用于研究突变对生长和发育的影响。
5. 2. Variants may have different characteristics from their parental strains.
   变种可能具有与亲本菌株不同的特征。
6. 3. Mutants are often used as models to study genetic diseases.
   突变体常被用作研究遗传疾病的模型。