John is homozygous dominant for cystic fybrosis gene, while jane is heterozygouse. calculate the chance of their child being a carrier and their child being affected by cystic fibrosis

Question

John is homozygous dominant for cystic fybrosis gene, while jane is heterozygouse. calculate the chance of their child being a carrier and their child being affected by cystic fibrosis

Answer 1

Cystic Fibrosis is a homozygous recessive condition, while being a carrier only requires having one copy of the recessive gene, also known as being heterozygous.

Now Let's do a Punnett square calculation using C to represent the dominant form of the gene and c to represent the recessive form of the gene.

John Jane

CC x Cc

F1 Generation (Child)

CC= 2/4 or 50%

Cc= 2/4 or 50%

cc= 0/4 or 0%

Thus, the child has a 50% chance of being Cc, or a carrier, and a 0% chance of being cc, which is the necessary genotype to be affected by cystic fibrosis.