Cohesion between sister chromatids, as well as tension created...

Question

Cohesion between sister chromatids, as well as tension created by the pull of kinetochore microtubules, is essential to ensure efficient separation of chromatids at mitotic anaphase or in meiotic anaphase II. Explain why sister chromatid cohesion is important, and discuss the role of the proteins cohesin and separase in sister chromatid separation.

Accepted Answer

Hi, everyone. Welcome back. Let's look at our next question. It says, how does the protein complex called cohesin ensure proper segregation of cysto chromatid and cell division? And what is the role of the enzyme called separates in this process? Well, we'll go through our answer choices. But first, let's just have in our minds what the roles of cohesion and separate races are. And luckily, we've got pretty good clues from their names. Cohesin maintains the cohesion of cysto chromatid, keeps them stuck to each other while separ Cleves the cohesion allowing the cytochrome tis to separate. And if we think about cell division in those processes, we can understand that these are important because you don't want those cymatics separating until the right time when they're lined up in the right place, they're in the middle and they'll properly separate to go into two different daughter cells. So you need them stuck together until the right time and then split apart at that time. So with this in mind, let's work our way through our answer choices. Choice. A cohesin prevents the separation of cysto chromatis during meiosis while separ facilitates the separation of homologous chromosomes during mitosis. Well, this is incorrect because it describes two separate things happening, preventing separation of sister chromatid during meiosis and are facilitating the separation of homologous chromosomes during mitosis. But these enzymes have their functions in both mitotic and myotic anaphase. So that's not our correct answer. So we're gonna cross that out. Choice. B says Cohesin maintains the cohesion between cysto chromatis while separates cleaves the cohesion to allow for the separation of Cytra chromatid during mitotic or myotic anaphase. And this is our answer. Those are the purposes we were thinking about. So we can go ahead and circle choice B but to be thorough, let's keep on going. Cho C says, Cohesin promotes the separation of cysto chromatis while separ prevents the binding of microtubules to the kinetic cord during anaphase. Well, this is incorrect as we know that Cohesin keeps the cysto chromatid uh together not promote the separation and separates cleaves. The cohesin doesn't have to have any purpose in preventing binding of microtubules. So choice C is not correct. And then finally, choice D cohesin is responsible for the formation of the spindle fibers while separation is responsible for the contraction of the microtubules during cytokinesis. Well, again, we know the roles of these two choice D is not correct. These are not the functions of cohesion and separ. So how does cohesin ensure proper segregation of cysto chromatid and cell division? And what is the role of separation in this process? Choice B cohesin maintains the cohesion between cytochrome while separ cleaves the cohesin to allow for the separation of cytochrome tits during mitotic or myotic anaphase. See you in the next video.

Key Concepts

Sister Chromatid Cohesion

Cohesin Proteins

Separase

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