 All right. I just spent a ridiculous amount of time looking up mono-e-mono and finding out that it means hand in hand, but might mean hand-to-hand combat, which I have no idea what, like really, that is certainly, I was not suggesting that we have hand-to-hand combat. If we are, you might wish that we had hand-to-hand combat when we are doing genetics heredity problems, but not me because I love this stuff. All right. Let's do a mono-hybrid cross, not a mono-hybrid battle of the hand fists. All right. Monohybrid crosses are when you cross two heterozygotes. So we have big P, little P. This is my F1 generation. Little boy did a mono-hybrid cross when he crossed his F1 babies with each other. And we're going to go through exactly the same process. What is the phenotype of these parents? We know because the big P is a dominant allele. We know that these are both purple phenotypes. You following me? Do we have the genotypes? We've got the genotypes. We've got the phenotypes given, so that's awesome. We've got the genotypes. We know the phenotypes. What's the next step? We need the possible gametes. Now is where, again, go back to the process of meiosis in order to make sure you understand that our gametes are going to segregate our alleles. And you can follow along a meiosis image that our gametes separate during metaphase. During metaphase, too, is when they actually are done separating. I mean anaphase. They line up on the equator in metaphase. You knew that already, didn't you? So my possible gametes, remember my gametes are always haploid. There's only one allele in each gamete. And these are my possible gametes, done. My possible gametes for old boy over here, done. I circle my gametes because I like to remember that you know what, these are gametes. My genotype is different. This is genotype. But my gametes are my sperm and eggs that I'm producing. Now we make our punnett square. And remember, a punnett square just has all my possible gametes on one side and on the other side from the other parent. Now we get to see that, yeah, on that last one it was super easy, but this one, you know, you can see that keeping track is actually going to be beneficial. If we combine these two gametes in fertilization to make this zygote, we're going to end up with a homozygous dominant pea baby with purple flowers. What? Did you follow that? That's magic. This one is going to have a big pea and a little pea. This one is a big pea and a little pea. It doesn't matter how you put your letters. It's irrelevant. There is no, no new information is gained from having little pea first or big pea or whatever order. I like putting my big letters first because I can read it easier. I can assess the situation. You see similarities easier when the letters are consistently listed, but it doesn't matter as long as you can read it. And then you know what else I like to do? I like to color code things because my brain is a color coded brain. So I look at this and I go, okay, homozygous dominant, that's going to be a purple flower. Heterozygous purple flower. And then I have to do it with, you wouldn't be able to see white, so I'll just do it in black because that's white on the other side of black. Homozygous recessive, white flower. If you count them up, you will see that we have three purple flowers for every one white flower. That's my phenotypic ratio. And that's the definition of a monohybrid cross. A monohybrid cross is a monohybrid cross. Where we cross two heterozygotes, always results in a three to one ratio. You don't have to do the Punnett square if you don't want to. You can totally know that my 75% of my babies are going to be, what's the word, purple. Okay, now, that was easy, right? Piece of cake, dihybrid cross. So we're going to cross a purple flower heterozygotes that also, it has some other heterozygous trait that we're going to keep track of. And this is going to get more complicated. The good news is a dihybrid cross also has a guaranteed phenotypic ratio that I will make you figure out. Dihybrid cross is coming at you. I never mind.