The sister chromatids by convention are now called sister chromosomes as they move toward opposing poles.

按照惯例，姐妹染色单体现在被称为姐妹染色体，因为它们朝向相反的两极移动。

Recombination occurs uniquely in each sex cell— making two sisters' chromosomes different not only from their parents', but from each other's.

在每个性细胞中发生的重组都是独一无二的——使两姐妹的染色体不仅不同于她们父母的，而且也不同于彼此的。