Question

If a baby boy inherits a recessive allele from his mother, in which of the following circumstances would he most likely exhibit that recessive trait?

Answer 1

You didn't post options, but the boy would exhibit the recessive trait whenever he does not have a dominant allele for the trait as well. That happens in two circumstances:

1. The allele is carried on an autosomal gene and he also inherited a recessive allele for the gene from his father.

2. The allele is carried on the X chromosome of which the boy has only the one which he inherited from his mother.

Hope this is helpful. :D

Answer 2

I think the boy will exhibit recessive trait only if he receives a recessive trait from his father who is heterozygous or homozygous recessive for that particular trait.