00:01
So we're looking at an organism that has one horn as the dominant allele and no horns as the recessive.
00:08
We're going to be crossing a heterozygous one with one that does not have horns.
00:12
What's the chances of the offspring having a horn? so let's go through this.
00:15
First of all, what letter is going to represent having a horn? we're going to have a capsule h because the letter doesn't matter so much, but it has to be capital because this is the dominant allele.
00:26
So that will represent having a horn.
00:28
I'll have little h for no horn, because little means it's going to be recessive.
00:34
So what is the genotype of a heterozygous one? heterozygous means it has two different alleles, so it'll have one of each.
00:42
But because a horn is dominant, it will have a horn.
00:49
Okay, and what is the genotype of one that does not have a horn? if it doesn't have a horn, it has to have two copies of the recessive.
00:59
So the phenotype will be no horn.
01:04
Okay, so now let's do this cross...