Predict the potential effect of the Lyon hypothesis on the retina...

Question

Predict the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color blindness trait.

Accepted Answer

Hi, everyone. Welcome back. Let's look at our next problem. It says, determine the correct statement about the lion hypothesis. And here's our answer. Choices. Choice. A says the paternal X chromosome of the female gets inactivated in somatic cells during the early embryonic stage. Choice B says the maternal X chromosome of the female gets inactivated in somatic cells during the early embryonic stage. Choice C, the inactivation of the X chromosome of the female occurs randomly in somatic cells during the early embryonic stage. And choice D the inactivation of the X chromosome of the female occurs randomly in each somatic cell after mitosis. So as we can recall from our content, videos, the lion hypothesis refers to the way in which in the female body, the fact that females have two copies of the X chromosome is dealt with as we recall having extra copies or not enough copies of a chromosome can be a big problem. So the fact that males and females have different numbers of that X chromosome would be an issue except in every cell in the female body. One of those X chromosomes is inactivated. And our answer choices offer us different options. Um A and B saying either the paternal or the maternal X chromosome is inactivated in that early embryonic stage of development C and D referring to the X chromosome getting inactivated randomly in each cell, either in the early embryonic stage in choice C or in each cell after mitosis. In choice D Well, our answer here is going to be choice C. The in inactivation of the X chromosome of the female occurs randomly in somatic cells during the early embryonic stage. So in that early embryonic stage, there's only a few cells there in each cell, either the maternal or the maternal X chromosome, no preference. Just by random chance, one of them gets inactivated in each of the cells present at that early embryonic stage. And therefore every daughter cell that arises from that particular embryonic cell has the same X chromosome inactivated. So that results in mosaicism in the female cells. Since you have these portions of daughter cells from each different somatic cell that was present at that early stage, that are a little different from each other depending on which X chromosome got inactivated. So choice A and Choice B are incorrect because it's not directed to either paternal or maternal. It's just by random chance and then choice D is incorrect because this inactivation occurs very early in embryonic development, not in each cell as it arises through mitosis. So we'll cross out D. So again, our answer here is choice C the inactivation occurs randomly in somatic cells during the early embryonic stage. See you in the next video.

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Predict the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color blindness trait.

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