Question

Cystic fibrosis is a recessive genetic disorder caused by a mutation of the CTRF gene. The disease is characterized by excessive mucus production along the respiratory and digestive tracts in addition to other symptoms. Cystic fibrosis is a progressive disorder that is most associated with chronic respiratory disease. Sara and Anthony found out that they are both carriers of the disorder, but neither have the disease. What are the chances their child will be born with cystic fibrosis?

Answer 1

1:4
This is from Study Island

Answer 2

1: 4

Step-by-step explanation:

Since both the parents in this case are the carrier of the cysytic fibrosis. Thus if a cross is carried out between the two parents , the punnet square will be as follows –

Genes of Parents X X

X XX XX

Y XY XY

Here the X is the carrier’s gene in both the parents

From the cross results it is clear that only one child (XX) is having both the mutated gene. Thus it will have the disease.

So the probability of an affected child is 1:4