A few questions I'm confused about from a class

[Adamn86]

First:

if you have a blood type that was an ambiguous phenotype, how would you go about finding out what your genotype was?

Second:

suppose this situation: You are called in to testify in a court case of disputed parentage and you choose to use the MN blood system to establish paternity. In this sytem, the alleles M and N are codominant. Legal proceedings dictate that evidence be presented indicated who CANNOT be the father.

a) suppose the mother and the child both have the type N blood, the husband has type MN, and the alleged father has type N. What would you advise the court, and why?

b)suppose the mother and the child both have type N blood, the husband has by M, and the alleged father has type MN. Now what would you advise the court, and why?

These are the two questions I am totally stumped on in my anthropology course, I cannot figure it out!

[mith]

whats ambiguous phenotype?

[Adamn86]

I think a phenotype which doesn't somehow manifest itself? I have no clue.

[mith]

I think the definition of phenotype is that it is observable. I don't know why it would be ambiguous.

[stopherlogic]

Is it not as simple as because both husband and alleged father have at least one N allele the parentage is still disputable for A.
If this is correct you can probably work out B.

[Qujibo]

a) If they are codominant then you know that the mother has two genes coding for N, the son has two genes coding for N which means that he would have received a N from his father. From this information there is No way to tell that the alleged father cannot be the father. In fact if you construct a punnet square (not really necessary for just a F1 generation cross) you can see that there is actually a 50% chance that the husband is not the father.

b) In this case you can clearly see that the husband is clearly not the father, As N and M are not dominant or recessive the child can only receive the other N from a father who is a carrier of the Gene, as the husband does not carry the N gene it is not possible for him to be the father.

As for the first question give a little more specification as to how the phenotype is ambitious?

[danni1708]

hey
i think from reading question A
that the alleged father wuld be the biological father..
as the blood type MN has the codominant alleles M and N, for an offspring with MN both genes wuld need to be present in the formation of the gametes
im not sure if this has helped at all..
xoxox