| 例句 |
Changes in chromosome structure are called chromosomal mutations or aberrations.染色体结构的改变称为染色体突变或畸变。Environmental pressures encourage genes with certain mutations to persist and others to die out.环境的影响使发生了某些突变的基因存活下来，另一些则消亡了。Cells become cancerous after subtle mutations occur that prevent them from carrying out their proper function.由于发生的微妙变化阻止了细胞发挥正常功能，细胞发生了癌变。 |