Albinism is a condition in which pigmentation is lacking. In humans, the result is white hair, non-pigmented skin, and pink eyes. The trait in humans is caused by a recessive allele. Two normal parents have an albino child. What are the parents' genotypes? What is the probability that the next child will be albino?

Question

Biology

Collier

20 December, 01:10

Albinism is a condition in which pigmentation is lacking. In humans, the result is white hair, non-pigmented skin, and pink eyes. The trait in humans is caused by a recessive allele. Two normal parents have an albino child. What are the parents' genotypes? What is the probability that the next child will be albino?

+2

Answers (1)

Know the Answer?

Mila Norris · Answer 1

1/4 or 25% chance / probability of having an albino child.

Explanation:

Albinism is a recessive trait, this means that a person need 2 copies of the allele to express this condition. If both parents are normal their genome must be Aa ("A"=normal condition and "a" recessive allele) when they produce gamets they could either be "A" or "a" but when fertilization happens there's a 25% chance of 2 gametes with the recessive trait to meet, hence producing an albino.

It is important to understand that this is only probability. A couple could have 6 children and all of them could be normal.