00:01
Looking at this very simple pedigree, we are going to try to determine what possible modes of inheritance could be affecting this pedigree.
00:08
It could be this particular gene that we're following.
00:12
The major options that we're going to look at and try to prove or debunk is autosomal, and it could be dominant or recessive.
00:23
It could be x -linked, again dominant or recessive.
00:28
It could be y -linked, and dominant or recessive.
00:34
Or it could be sex limited.
00:39
If it's sex limited, it could be dominant or recessive, but it could also be male or female.
00:44
We have lots of options here, and these are not all the options, just the major ones that we're going to look at now.
00:50
Starting off with autosomal, this is the most simple that we could have a gene.
00:56
In this case, since mom has the trait and no one else does, we could look at it from the perspective of dominant or recessive.
01:06
If it's dominant, that would mean mom has at least one dominant allele, and all the other individuals who don't have the trait have no dominant alleles.
01:17
That would mean mom would have to be heterozygous.
01:19
She would have to carry a recessive allele that she could pass on to the children, but this is possible.
01:26
If instead this was a recessive trait, meaning you could only have the trait if you had only recessive alleles, that would mean mom would have two recessive alleles and everyone else would have at least one dominant.
01:40
In this particular case, it would probably mean that dad has two dominant alleles, so all the offspring had to get a dominant from dad...