Question

Suppose two brown haired parents have a red haired child what are the genotypes of each parent? And what % for them to have red hair children? What would the children’s genotypes be?

Answer 1

1) B- brown;  b- red hair

 Having brown hair is a dominant trait while red hair is recessive.
If the parents had a red-haired child it means they were carriers of the red hair trait, so their genotype is  Bb
 
2)Getting their genotypes together would result in the possibilities that you see at the image below.
1/4 = 25% BB - brown
2/4 = 50% Bb brown but carrier
1/4 = 25% bb red hair
Answer: 25%
 
3) The genotype of the child, as i said before would be bb. By having both alleles being recessive the child will show red-hair. If it was any other genotype( BB or Bb), the child would have brown hair, like their parents.

Answer 2

25% chance of having a red-haired child.

The genotypes of the children would most likely be homozygous recessive.