Question

1. In humans, the ability to sing well is dominant over the recessive trait of being a terrible

Answer 1

The probability of Sean to both sing and dance well is 50%.

Explanation:

The gene that is dominant is expressed in phenotype of the individual and the genes are actually obtained from the parents.

Here two characters are mentioned which are singing and dancing.

The dominant character i.e able to sing is marked by gene S and the corresponding recessive allele is marked by gene s.

Similarly, the ability to dance is marked by gene D and recessive allele is marked by gene d.

So, the mother is heterozygous and she can sing well, but can't dance. So her genotype is Ssdd.

The father can't sing and is homozygous, so his genotype is ssDD.

Gametes from the mother is Sd and sd. While the gamete from the father is sD.

So the probabilities of the progenies are SsDd and ssDd.

So the probability of Sean to both sing and dance well is 50%.