Sister chromatids during meiosis > Sister chromatids > > $A)$ Cross over during prophase I of meiosis > > $B)$ separate during the first mitotic division > > $C)$ are produced during $S$ phase between cell divisions > > $D)$ cross over during prophase II of meiosis > > $E)$ are also called homologous chromosomes My thoughts: > * $A$ is incorrect because it's **nonsister** chromatids that cross over > * $B$ is incorrect because they separate during the **second** mitotic division > * Don't know about choice $C$ > * $D$ is incorrect because there is no crossing over during Meiosis II > * $E$ is incorrect because well...it's just not true > So is the answer $C$?

It is **C**. During S-phase the DNA of each chromosome duplicate and the two sister chromatids formed get attached by cohesin proteins. These sister chromatids separate at Anaphase-II of Meiosis.

From wikipedia:

> A sister chromatid refers to either of the two identical copies (chromatids) formed by the replication of a single chromosome, with both copies joined together by a common centromere. In other words, a sister chromatid may also be said as 'one-half' of the duplicated chromosome. A full set of **sister chromatids is created during the synthesis (S) phase of interphase** , when all the chromosomes in a cell are replicated.