sister chromatids are attached to one another at a common centromere.
sister chromatids are attached to one another at a common centromere.
where are sister chromatids attached to one another?
a common centromere
sister chromatids









































a sister chromatid refers to the identical copies (chromatids) formed by the dna replication of a chromosome, with both copies joined together by a common centromere. in other words, a sister chromatid may also be said to be 'one-half' of the duplicated chromosome. a pair of sister chromatids is called a dyad. a full set of sister chromatids is created during the synthesis (s) phase of interphase, when all the chromosomes in a cell are replicated. the two sister chromatids are separated from each other into two different cells during mitosis or during the second division of meiosis.
sister chromatids
the bfb cycle begins when the end region of a chromosome, called its telomere, breaks off. when that chromosome subsequently replicates it forms two sister chromatids which both lack a telomere. since telomeres appear at the end of chromatids, and function to prevent their ends from fusing with other chromatids, the lack of a telomere on these two sister chromatids causes them to fuse with one another. during anaphase the sister chromatids will form a bridge where the centromere in one of the sister chromatids will be pulled in one direction of the dividing cell, while the centromere of the other will be pulled in the opposite direction. being pulled in opposite directions will cause the two sister chromatids to break apart from each other, but not necessarily at the site that they fused. this results in the two daughter cells receiving an uneven chromatid. since the two resulting chromatids lack telomeres, when they replicate the bfb cycle will repeat, and will continue every subsequent cell division until those chromatids receive a telomere, usually from a different chromatid through the process of translocation.
breakage-fusion-bridge cycle