During DNA duplication in the S phase, each chromosome is replicated to produce two identical copies, called sister chromatids, that are held together at the centromere by cohesin proteins. Cohesin holds the chromatids together until anaphase II.
How are sister chromatids held together?
The two identical chromosomes that result from DNA replication are referred to as sister chromatids. Sister chromatids are held together by proteins at a region of the chromosome called the centromere.
Are sister chromatids held together by spindles?
… that holds together the two chromatids (the daughter strands of a replicated chromosome). The centromere is the point of attachment of the kinetochore, a structure to which the microtubules of the mitotic spindle become anchored. The spindle is the structure that pulls the chromatids to opposite ends of the cell…
Why do sister chromatids line up?
The sister chromatids line up at the equator, or center, of the cell. … The spindle fibers ensure that sister chromatids will separate and go to different daughter cells when the cell divides. Chromosomes, consisting of sister chromatids, line up at the equator or middle of the cell during metaphase.
What is the relationship between sister chromatids and homologous chromosomes?
Homologous chromosomes are a couple of one maternal and one paternal chromosome, paired up during fertilization in a diploid cell. Two copies of one chromosome, linked together in the centromere are called sister chromatids.
What protein is responsible for holding the sister chromatids together and in what phase of mitosis does it break down?
Answer b is correct. This is one of the events that occur during anaphase. During anaphase, the cohesin proteins binding the sister chromatids together also break down, and the non-kinetochore spindle fibers lengthen, elongating the cell. Answer a occurs during metaphase, which happens before anaphase.
How are chromatids joined?
Following DNA replication, the chromosome consists of two identical structures called sister chromatids, which are joined at the centromere.
How do sister chromatids stay together in anaphase 1?
Unlike in mitosis, the sister chromatids remain attached at their centromeres by cohesion, and only the homologous chromosomes segregate during anaphase I. The second meiotic division is exactly like the division in mitosis, with separation of the sister chromatids.
Do sister chromatids separate during meiosis?
Meiosis II is the second division of meiosis. It occurs in both of the newly formed daughter cells simultaneously. Meiosis II is similar to Mitosis in that the sister chromatids are separated.
During which phase of meiosis do the sister chromatids line up across from each other in the center of the cell?
During prophase II, sister chromatids align at the center of the cell in singular chromosome structures. These sister chromatids are separated during anaphase II, resulting in a total of four haploid cells.
During which stage do the sister chromatids separate?
Metaphase leads to anaphase, during which each chromosome’s sister chromatids separate and move to opposite poles of the cell. Enzymatic breakdown of cohesin — which linked the sister chromatids together during prophase — causes this separation to occur.
What does a centrosome look like?
Centrosomes are made up of two, barrel-shaped clusters of microtubules called “centrioles” and a complex of proteins that help additional microtubules to form. This complex is also known as the microtubule-organizing center (MTOC), since it helps organize the spindle fibers during mitosis.