Please help with the following question, 1.The first of three children of two no
ID: 97390 • Letter: P
Question
Please help with the following question,
1.The first of three children of two normally pigmented parents has albinism, a recessive trait that results from lack of the pigment melanin.
a.Given that the normal allele is A and the albino allele is a, draw this pedigree and label both the phenotypes and genotypes.
b.What is the probability that the second child, who shows normal pigmentation, is a carrier?
c.What is the probability that both unaffected children are carriers? INCLUDE LOGIC STATEMENT(s)
d.What is the probability that only one of the two unaffected children is a carrier? INCLUDE LOGIC STATEMENT(s)
Will give a thumbs up if correct, thank you so much for your help.
Explanation / Answer
1.The first of three children of two normally pigmented parents has albinism, a recessive trait that results from lack of the pigment melanin.
a.Given that the normal allele is A and the albino allele is a, draw this pedigree and label both the phenotypes and genotypes.
normal allele is A and the albino allele is a
Parents= Aa x Aa
A
a
A
AA (normal)
Aa(carrier)
a
Aa (carrier)
Aa (albino)
b.What is the probability that the second child, who shows normal pigmentation, is a carrier?
Probability of being a carrier for this parents is ½
Since the first child is already a known albino, the remaining chance of being a carrier
probability that the second child being a carrier is 2/3
c.What is the probability that both unaffected children are carriers? INCLUDE LOGIC STATEMENT(s)
probability that both unaffected children are carriers is x = 4/9
(probability of each of them being a carrier is , therefore both of them being carriers is 4/9
d.What is the probability that only one of the two unaffected children is a carrier? INCLUDE LOGIC STATEMENT(s)
One is a known albino, the other is non carrier, therefore the probability that only one of the two unaffected children being a carrier is 100%
A
a
A
AA (normal)
Aa(carrier)
a
Aa (carrier)
Aa (albino)