00:01
Galactosemia is a recessive human disease.
00:03
Susan and her husband are both heterozygous for the galactosemia gene.
00:08
If they have two children, what is the probability that one of the children will be male and affected, and the other will be female and unaffected? so it looks like this is an autosomal gene, so it's not sex -linked.
00:28
So let's use letter g to represent the dominant alleles.
00:33
Again, this is an autosomal.
00:39
So capital g stands for normal and lower g disease.
00:52
Since both of them are heterozygous, then our planet square will be the two parents.
01:08
Each will produce two alleles, capital g and lower g.
01:13
And then the other parent, same thing, capital g.
01:16
And lower g.
01:17
Now the f1 generation, you put the two allele back together.
01:25
So you can tell that although you have one homozygous and two heterozygous, these three all have dominant allele.
01:36
They will be wild type.
01:38
So three fourths normal, no disease, and one fourth, the one that that is homozygous lower g affected...