Question

In humans, a type of blindness is due to a dominant allele (B). Normal vision is the result of a

Answer 1

Answer:

Yes, a child with normal vision who does not suffer from headaches can be produced.

The probability of producing such child from this cross is 1/2 or 50%

Explanation:

This question involves two distinct genes in humans. One coding for blindness and the other for Migraine headaches. The alleles for blindness (B) and Migraine (M) are dominant over the alleles for normal vision (b) and no Migraine (m).

According to the question, a male who is heterozygous for blindness and does not suffer from migraines will have the genotype; Bbmm while a female who

has normal vision and does not suffer from migraines will have genotype; bbmm. If these two parents are crossed, the following genotypes of gametes will be produced by each parent:

Bbmm- Bm, Bm, bm and bm

bbmm- bm, bm, bm, and bm

Using these gametes to construct a punnet square (see attached image), the following offsprings with genotypes; Bbmm and bbmm in the ratio 1:1 will be produced.

Bbmm (8/16) are offsprings with blindness and have no Migraine headache

bbmm (8/16) are offsprings with normal vision and have no migraine headache

Hence, this cross can produce a child with normal vision who does not suffer from headaches (bbmm). Also, the probability of producing such child is 8/16 or 1/2.