Question

Suppose that gene b is sex-linked, recessive, and lethal. A man marries a woman who is heterozygous for this gene. If this couple had many normal children, what would be he predicted sex ratio of these children?

Answer 1

Lethal when? If lethal after many years, the sex ratio is 1:1. If lethal in the womb, then one boy for every two girls, as the other boys died in the womb.

Answer 2

what would be the punnet square

i can it do it myself but what about genotype and phenotype

Answer 3

Woman = Bb
Man = By, since the lethal gene is sex-linked, it is not on the y chromosome. From this, you should be able to do the Punnet square to get the genotypes. From them, you can figure the phenotypes.