Question

In humans, a type of blindness is due to a dominant allele; normal vision is the result of a recessive allele. Migraine headaches are due to a dominant allele, and normal (no headaches) is recessive. A male who is heterozygous for blindness and does not suffer from headaches marries a woman who has normal vision and does not suffer from migraines. Could they produce a child with normal vision who does not suffer from headaches? If yes, can the probability of such a child be determined?

Answer 1

Yes.

Probability of such child = 1/2 or 50%

Step-by-step explanation:

According to the question, below are the genotypes and phenotypes possibilities:

aa = normal vision & no headache

Aa = normal vision & no headache

AA = blindness & headache

Male Female

Aa aa

Possible genotypes of progeny: Aa Aa aa aa

So it is clear that out of the 4 probable children, 2 with 'genotype aa' will have normal vision & no headache.

Mathematical expression is as under:

2/4 = 1/2 that means 50% progeny.