Question

A family is planning on having a baby! So cute! They want to know the chance of them having some rare traits in the family. They hope the baby has freckles (F) with blonde hair (b). Freckles are inherited by complete dominance. Options for hair color are black, brown, or blonde. BLT1 does not have freckles, but has blonde hair. BLT 2 is heterozygous for freckles and has brown hair. What is the chance of their children having freckles and blonde hair

Answer 1

The chance of the couple's children having both freckles and blonde hair is 25%, determined by using a Punnett square and considering the simple dominant-recessive inheritance patterns of these traits.

Step-by-step explanation:

To determine the chance of the couple's children having freckles and blonde hair, we need to consider the genetics of these traits. Freckles (F) follow a complete dominance inheritance pattern where 'F' is dominant for freckles and 'f' is recessive (no freckles). The hair color is also a trait with dominant and recessive alleles, where 'B' is dominant for brown or black hair and 'b' is recessive for blonde hair.

BLT1 is 'ff' for freckles and 'bb' for hair as they have no freckles but have blonde hair. BLT2 is 'Ff' for freckles (heterozygous) and 'Bb' for hair (non-blonde). To determine the probabilities, we can set up a Punnett square:

• For freckles, the cross is 'Ff' (from BLT2) x 'ff' (from BLT1), giving us a 50% chance of children having freckles (Ff or Ff genotype) and a 50% chance of not having freckles (ff genotype).
• For hair color, the cross is 'Bb' (from BLT2) x 'bb' (from BLT1), giving us a 50% chance of children with brown or black hair (Bb or Bb genotype) and a 50% chance of blonde hair (bb genotype).

Combining both traits, the chance for a child to have both freckles and blonde hair is the chance for freckles (50%) multiplied by the chance for blonde hair (50%), resulting in a 25% probability.