 Introducing Mendel's peas and the characteristics that he kept track of. Now, here's the deal. He's this monk doing his monthly business and he made pea babies and then counted the characteristics of the pea babies, keeping track of the pea parents. And he looked at the seed color, he looked at the shape of the seeds, he looked at the coat of the seed, the color of that, the shape of the pod, the pod color, the flower position. I believe flower color is one of them as well and stem length, height, tallness, etc. Okay, let's make a list of these because as I told you, it was a little bit magic and I kind of want to draw you a picture of the chromosomes themselves because it's really important to remember that each one of these characteristics is carried on a different chromosome. So let's look at the first one. Let's just go with seed shape and we can indicate seed shape with letters. There are two different alleles for each of these, each of these characteristics and I'm going to draw the chromosome. So here it is, this chromosome has the S gene right here. So you can have a big S allele or a little S allele. He also looked at seed color. I didn't draw you the actual, like what... I didn't draw you the shape of the seed itself. Maybe I should do that because you can have smooth ones or wrinkled. I'm going to get the idea here. As far as seed color goes, you can have, let's see, we're going to denote that with a big Y or a little Y and you can have a yellow seed or a green seed and I'm going to draw a different chromosome because look, this one is on this chromosome and let's just say that the gene is down here at the bottom of this chromosome. Okay, do you see what I'm doing? Let's look at the flower color because I think I used that one as an example. Flower color, we're going to use the letter P and we can have a purple flower or a white flower and look, I'm going to draw a different chromosome for this one and I'll say that the gene is here on this chromosome. Do you see how I have different chromosomes? So this is chromosome one, chromosome two, chromosome three in P land and I have the gene that codes for each one of these different traits. I'm going to do one more because I think that I do stem length. I think that's one of our examples as well, whatever. And stem length can be either tall or short. Let's write that down, tall or short and I'm just going to draw another, let's say this one looks kind of boxy, like a, like a that and here's my allele or here's my gene for stem length. Do you follow what I just am doing? I could do this for all seven of them. I'm not going to do it for all seven but the next thing that we need to talk about is some terminology that will help us in doing heredity problems because the fact is that we've got all sorts of information here and we need some words to be able to describe it and you probably could tell that already because I was trying not to use those words until I defined them for you. So I'm going to come back to this exact page and give you some new words to describe things here.