Question

In humans, cystic fibrosis is a recessive genetic disorder that results in mucus clogging major organs. If both parents are genetically heterozygous for cystic fibrosis, then what are their chances of having a child with the disease? A) 25% B) 50% C) 75% D) 100%

Answer 1

25%

Step-by-step explanation:

i did the usatestprep.

Answer 2

Heterozygous parents have genotype Aa. If we cross two of them then:

Parents: Aa x Aa

F1 generation: AA Aa Aa aa

This means that the chances of having a child with the disease are ¼ (or 25%) and that is the child with genotype aa (homozygous recessive).