Question

In Humans freckles (F) is dominant to no freckles (f). If A man and woman both have freckles and they have a child with no freckles what must be the genotype of the parents?

Answer 1

The genotype of the parents is Ff and Ff.

Step-by-step explanation:

Data given:

freckles = dominant, FF or Ff genotype

no freckles = recessive, ff

genotype of parents with freckles = ?

child has no freckles = ?

The possibility of the child having no freckles is because the parent could be heterozygous dominant for the trait i.e freckles.

The genotype is Ff X Ff

F f

F FF Ff

f Ff ff

It can be seen from the Punnet square that there are 25% chance of the child to be with no freckles when both parents are having freckles.

The genotype ratio is 1:2:1

The phenotype ratio is 3:1

3 with freckles and 1 with no freckles.