着丝点是染色体的主缢痕，在这个地方姐妹染色单体连在一起。

Centromere is the primary constriction on the chromosome, a region at which the sister chromatids are held together.

youdao

染色体的主缢痕，使姐妹染色单体连在一起，在其两侧各有一个由蛋白构成的动粒。

Centromere --- The primary constriction on the chromosome, a region at which the sister chromatids are held together and at which the kinetochore is formed.

youdao

此时每条染色体由一对染色单体构成，这两条联合的染色体称为四分体。

At this point esch chromosome consist of a pair of chromatids and the two associated chromosomes are termed a tetrad.

youdao