Suppose you are heterozygous for two genes that are located on different chromosomes. You carry alleles A and a for one gene and alleles B and b for the other. On the diagram, identify the events responsible for the principle of segregation and the principle of independent assortment.

Video transcript

Welcome back. Here's our next problem. It says which of the following events, explains the principle of segregation and the principle of independent assortment. Well, we know the principle of segregation is that every individual has two alleles of any particular gene and only one of these this past to any offspring. The principle of independent assortment does that inheritance of one pair of jeans is independent of the inheritance of the other. So, our two principles here that the only one of a set of values has passed to offspring. Principle of independent assortment. That the inheritance of one pair of jeans independent of the inheritance of the other. So now this is of course we know today, compared to what Mendel understood, this is only the case if there on different chromosomes. Mendel got lucky in his pea plant experiments that the genes for shape and color, which is what he was looking at were on different chromosomes. Or he might have come up with a different answer. So we'll clarify that's on different chromosomes. So, our answer choices we have are a mitosis, beam, aosis, c mitosis and mitosis, or D None of the above. Well, mitosis is not going to show either of these principles because mitosis just duplicates the parent cell. You end up with daughter cells identical to the parent cell. So we're not looking at separating alleles or a sorting independently. We're just doing a cloning essentially of the parent cell. So any of the answer choices involving mitosis, we can go ahead and eliminate. So it's not a it's not mitosis and mitosis. So our choices. Either mitosis or none of the above. Well aosis does show these two principles and I'll just do a quick sketch here. I'm going to use letters for the alleles just to symbolize the chromosomes with those allies. Because I don't wanna have to draw squiggles all over. So let's imagine a hetero sex parent for P shape. With one dominant and one recessive allele. Well so this will stand for the chromosome with the salio, well after mitosis before daughter cells that are produced here We'll each have one. I will two with the dominant and two with the recessive because these two chromosomes are physically separated during my oh sis one as they then separate from each other. So we see that the two alleles are separated and the offspring will inherit only one of the alleles from this parent, the other away from the other parent obviously. So there's our principle of segregation independent assortment, let's look at a parent with two different genes and this parent happens to be hetero for P. Shape and pea color. Well when these chromosomes Line up two separate they can line up in different ways. So let's imagine um we're in meta phase here. This little squiggles so we know they're not daughter cells. They're lined up in the middle of the cell. Well they can line up with the chromosome with big R on this side. So little are on this side and then you could have big Y on the side and little Y on the side. When they separate. You're gonna end up with daughter gametes, two of which will have two dominant. How else? And then two of which will have two recessive values. However they don't have to line up like this. They could line up differently. It could be that the chromosome with the big R. Lines up on the same side of the cell with the chromosome with little Y. And the chromosome with little. Our lines up with the chromosome with big Y. Well then our daughter gam is here. We'll have Big R. Little Y. Or they would have little R. Big Y. So as we see, just depending on how the chromosomes line up, there's no reason that Big R. Has to line up with Big Y. They assort independently of each other since they're on two different chromosomes. So we see that mitosis shows both of these principles. So our answer will not be none of the above. Our answer will be Mayo's is showing both of these principles. Choice B. See you in the next video