Explain how the behavior of homologous chromosomes in meiosis ...

Question

Explain how the behavior of homologous chromosomes in meiosis parallels Mendel's law of segregation for autosomal alleles D and d. During which stage of M phase do these two alleles segregate from one another?

Accepted Answer

Welcome back, everyone. Let's look at our next question. It says during which stage of meiosis do homologous chromosomes segregate from each other, which parallels Mendel's law of segregation. For autosomal. All our answer choices are a pro phase one B meta phase one C anta phase one or D tele phase two. Well, when I'm trying to answer questions about the phases of meiosis, I always like to keep straight in my head. What's going on in meiosis one versus what's going on in meiosis two. So in Meiosis one we have the separation of homologous chromosomes resulting in two haploid daughter cells. So we start out with one chromosome from each parent of every chromosome and those chromosomes get separated from each other resulting in daughter cells that each have only one of each chromosome. And then in Meiosis two, we have the separation of sister chromatid And our single chromosomes there resulting in a total of four haploid daughter cells. So with that in mind, let's look at our answer choices, recalling that we're trying to look for this stage at which homologous chromosomes segregate from each other. Well, when we think about the chromosomes being pulled apart, I think of the word away begins with A and that reminds me of Anna phase, which also begins with a And we're talking about meiosis one because we still have homologous pairs. And indeed choice C is Anna Phase one. So that's going to be that phase where the homologous pairs have been lined up in that middle area of the cell and are pulled apart from each other to be segregated into separate daughter cells. Let's just look at our other answer. Choices to see why they're not correct. Choice A is pro phase one. And in pro phase, you will have, I think of pro phase with A P and pair with A P. In pro phase one, you'll have homologous chromosomes pairing up and crossing over events occurring, but that's not what we're looking for. So choice A isn't the right answer. Choice B metaphor one. Again, I like to think of M for meta phase and M for middle and meta phase one, those paired chromosomes line up at the meta faces plate of the cell. So right in the middle of the cell, but that's not what we're looking for. So choice B is not our answer. And then finally choice D tele phase two. So we're talking about meta meiosis two. So when the cysto chromatis are separating and tele phase is that last part as cytokinesis occurs, and we have the formation Of our four haploid daughter cells. So that very last stage of the whole process. So not our answer choice, eliminate choice D and we have during which stage of meiosis, two homologous chromosomes segregate from each other which parallels Mendel's law of segregation for autosomal all choice C and A phase one. See you in the next video.

Explain how the behavior of homologous chromosomes in meiosis parallels Mendel's law of segregation for autosomal alleles D and d. During which stage of M phase do these two alleles segregate from one another?

Key Concepts

Homologous Chromosomes

Mendel's Law of Segregation

Meiosis Stages

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