The spindle fibers shorten and the centromere divides, so each chromosome becomes two separate chromatids.

纺锤丝缩短了，着丝粒分裂，所以每个染色体变成两个独立的染色单体。

The DNA is exactly replicated, and each chromosome now becomes two identical chromatids joined by the centromere.

DNA 被精确地复制了，每条染色体现在变成了两条由着丝粒连接的相同染色单体。

As a result, a double-stranded break on one of the chromosomes can be repaired by using the sister chromatid.

所以，一条染色体上的双链断裂可利用其姐妹染色单体进行修复。

Sister chromatids remain attached during telophase 1.

姐妹染色单体在末期 1 保持附着状态。

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。

Chromatid is the word we use to describe the newly copied chromosome: the identical copies.

染色单体是我们用来描述新复制的染色体的词：相同的副本。

The cell membrane pinches to separate the two sets of chromatids into two cells.

细胞膜挤压将两组染色单体分离成两个细胞。

Anaphase 1 Kinetochore microtubules shorten, pulling homologous chromosomes, which consist of a pair of sister chromatids, to opposite poles.

后期 1动粒微管变短，将由一对姐妹染色单体组成的同源染色体拉向相反的两极。

That donor DNA will act like a sister chromatid as a reference to recreate the lost genetic information.

该供体DNA会像姐妹染色单体一样，作为重建遗传信息的参考。

Each daughter cell now has half the number of chromosomes but each chromosome consists of a pair of chromatids.

现在每个子细胞都有一半的染色体，但每个染色体都由一对染色单体组成。

In the second cellular division called meiosis II, the sister chromatids of a given chromosome are separated.

第二次细胞分裂，也就是第二次减数分裂后，每个染色体的姐妹染色单体分离。

This is followed by anaphase 2, in which the remaining centromeric cohesion is cleaved, allowing the sister chromatids to segregate.

紧随其后的是后期 2，在这一阶段，着丝粒纵裂，姐妹染色单体分离。

Non-sister chromatids of homologous chromosomes may exchange segments over regions of homology.

同源染色体的非姐妹染色单体可以在同源区域交换片段。

At this stage, non-sister chromatids may cross-over at points called chiasmata (plural) , (singular: chiasma) .

在这个阶段，非姐妹染色单体可能会交叉。

Meiosis 2 Meiosis 2 is the second meiotic division and usually involves equational segregation, or separation of sister chromatids.

减数分裂 2减数分裂 2 是减数分裂的第二次分裂，通常涉及相等的分离，或姐妹染色单体的分离。

Early on in meiosis the germ cell makes a copy of all of its chromosomes with each chromosome having sister chromatids at that point.

减数分裂早期，生殖细胞会复制原先的染色体，复制完毕后，所有的染色体都有了姐妹染色单体。

The other option is the sister chromatids of the x chromosome don't separate in meiosis two in the female germ cell.

女性生殖细胞中，X染色体姐妹染色单体在第二次减数分裂时没有分离。

So now End 1 is placed near a similar nucleotide sequence, called the homologous sequence, because it's found in the same spot on the homologous sister chromatid.

现在End 1位于一段相似核苷酸序列附近；这段序列被称为同源序列，位于同源姐妹染色单体上的相同位点。

Since homology-directed repair uses a sister chromatid as a template, this is a more reliable repair mechanism than non-homologous end joining because there's no loss of nucleotides.

由于同源介导修复是以姐妹染色单体为模板，这种修复机制比非同源末端连接更可靠，因为没有核苷酸丢失。

The paired and replicated chromosomes are called bivalents or tetrads, which have two chromosomes and four chromatids, with one chromosome coming from each parent.

配对和复制的染色体被称为二价体（也称为四分体），它们有两条染色体和四个染色单体，每个亲本都有一条染色体。