Dominant vs. Recessive Alleles

by Jason Amores Sumpter
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in this video, we're going to begin our lesson on Gina type versus phenotype. But before we can define genotype and phenotype, its first helpful to distinguish between the dominant and recessive a Leal's and so recall from our previous lesson videos that Ah Leal's are really just different versions of specific genes. And it turns out that a Leal's can be either dominant or recess ivo. And so the dominant ah Leo, as its name implies, is going to be in a Lille that dominates and exerts its effects whenever it is present. And so the dominant Khalil is usually symbolized with a capital letter. Now the recess. Ivo A. Leo, on the other hand, is, as its name implies, recess if I've meaning that it's going to have no effect if a dominant Khalil is present. And so the recess of Alil can Onley have its effect when there is no dominant Alil? And so the recess of Leo is symbolized using a lower case letter. Now, as Gregor Mendel was studying these P plants, what he realized is that the alil for Yellow piece was actually dominant to the olio for Greenpeace. And so this, of course, means that the yellow Khalil was going to be the dominant olio and the green Khalil is going to be the recess. Ivo Alil. And so if we take a look at our image down below, we can better distinguish between dominant and recessive a Leal's. And so notice over here we're showing you that the dominant Alil here is gonna be represented using a capital letter. And so here we're using the capital letter. Why? To represent the dominant Eliel for yellow pea color. And so you can see here that this dominant Alil really looks pretty dominant here in this image with these large muscles and the recess of Alil over here, on the other hand, is represented using lower case letters. So we have the lower case letter. Why? And the recess of Alil is not going to be dominant. It is not going to exert its effect if a dominant Khalil is present. And so you can see that the recess of the Leo here is kind of looking afraid of the dominant Alil. And again, the recess of a Leo here would be the polio for green pea color. And so what will notice moving forward is that the dominant Alil here is going to mask or hide the effect of the recess of Alil whenever the dominant Khalil is present. And so this here concludes our introduction to the difference between dominant and recessive alleles and will be able to get some more practice applying these concepts as we move forward in our course, and in our next video, we'll talk more about the difference between genotype and phenotype, so I'll see you all there.