A woman with thin lips marries a man with thick lips, whose father had thin lips. What is the probability that a child

A woman with thin lips marries a man with thick lips, whose father had thin lips. What is the probability that a child with thin lips will be born in a given family, and how many different genotypes can there be among the children of a given married couple, if it is known that in a person the gene for thin lips is recessive with respect to the gene for thick lips?

Let’s designate the gene for thick lips as A, and for the gene for thin lips as a.

The mother’s genotype aa is homozygous for a recessive trait. The male genotype Aa is heterozygote. The man is a carrier of the recessive gene, since his father, the owner of thin lips, was homozygous for a recessive trait.

R: aa x Aa – parent individuals

G: a x A, a – possible gametes

F1: Aa – thick lips (50%)

aa – thin lips (50%)

Answer: the probability of having a baby with thin lips is 50%, possible offspring genotypes: Aa and aa.