突变可以是由辐射、化学作用、外部病原体(如：病毒)或细胞分裂时基因组复制错误造成。

Mutations can be induced by radiation, chemical treatment, foreign pathogens (e.g. viruses), or due to errors that occur during replication of the genome each time a cell divides.

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本文主要对辐射诱发染色体畸变和微核的形成与细胞分裂周期的关系作了综述和分析，并对微核细胞率作为辐射损伤的细胞学指标进行了评价。

This paper reviewed the relationship between chromosomal aberrations at the different stages of mitotic cycle and the mechanism of chromosomal aberrations and micronuclei induced by radiation.

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