Question

In humans, freckles (F) on the skin are dominant to no freckles (f). If two parents are heterozygous for the trait, which statement below best describes their chances of having a child with no freckles?
A
If the parents already have three children with freckles, then they are more likely to have a child without freckles.
B
Every time they reproduce, the parents have a one in four chance of having a child without freckles.
C
It would be extremely rare for the freckled parents to have a child without freckles because freckles are dominant.
D
The parents will have three children with freckles before they have a child without freckles.

Answer 1

B

Each pregnancy is an independent event. With Ff × Ff the genotype ratio is 1 FF : 2 Ff : 1 ff, so each child has a 1/4 chance of being ff (no freckles) regardless of previous children.