The gene for albinism in humans is recessive. That is, carriers of this gene hav

Question

The gene for albinism in humans is recessive. That is, carriers of this gene have probability 1/2 of passing it to a child, and the child is albino only if both parents pass the albinism gene. Parents pass their genes independently of each other. Suppose that both parents carry the albinism gene. What is the probability that their first child is albino? If they have two children (who inherit independently of each other), what is the probability that both are albino? Neither is albino? Exactly one of the two children is albino? If they have three children (who inherit independently of each other), what is the probability that at least one of them is albino?

Explanation / Answer

a) P(First child is Albino) = P(Both parents pass their albinism gene) = (1/2)*(1/2) = 1/4

b) If they have two children:

P(Both are albino) = (1/4) * (1/4) = 1/16

P(Neither is albino) = (3/4) * (3/4) = 9/16

P(Exactly one of the two children is albino)

= P(First child Albino) * P(Second child non Albino) + P(First child non Albino) * P(Second child Albino)

= (1/4) * (3/4) + (3/4) * (1/4)

= 6/16

= 3/8

c) If they have three children:

P(At least one of them is albino)

= 1 - P(None of them are albino)

= 1 - (3/4) * (3/4) * (3/4)

= 1 - 27/64

= 37/64

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.