00:01
So let's go over what we know about blood type.
00:05
So for blood type, there is type a, type b, type a, and type o.
00:18
So blood type has this thing called codominance, which we can see by blood type a, b here.
00:27
So codominance is basically when you have two different alleles, and both of them are competing for dominance.
00:36
One is not recessive to the other.
00:38
Whereas type o blood type would be kind of like the true recessive allele here, where you would only get type o blood type if a person had only type o alleles passed on to them.
00:57
So for this problem, we know that mom has type a.
01:02
So she is type a.
01:05
So her two allele combinations could be both being type a.
01:12
So these eyes are just how we denote her allele combinations, like her genotype, where the letter a over here would be her phenotype, so what she's showing.
01:24
So this is one possible allele combination for her.
01:28
The other one would be this.
01:31
This, one type a allele and one type o allele.
01:38
Or i guess i should, it would actually look like this because type o is denoted with like a little eye.
01:44
So a person who, let's use blue here, a person who only has type a alleles could only pass on their type a alleles.
01:55
And therefore they would have type a blood type and all of their children would get a type a allele.
02:00
However, a person who looks like this would also have type a blood type because they have that type a allele and their o allele is recessive to that type a allele.
02:15
So we know that mom has to look like this because she has type a blood type, but one of her children has type o blood type.
02:24
So they must have gotten a type o allele from their mom.
02:29
So, we are wanting to know what could be the blood type of the child's father.
02:39
What are the possibilities there? so this is a little bit tricky because you immediately think, oh, it's got to be typo.
02:49
Because type o blood type looks like this as far as alleles.
02:55
And then their phenotype would be type o blood.
02:58
That makes sense.
02:59
But that's not the only combination.
03:02
So just like here, i know my lines are getting confusing, but just like here where we have a person with type a blood type, even though they have one type a allele and one type o allele, that could be the genotype of the father as well.
03:20
So if we think about it as in like a punnet square, i'll draw one over here.
03:28
So this could be mom...