Question

Paula and Jerome have a normal child, Sheila. Both Paula and Jerome have a mother who is affected by cystic fibrosis, an autosomal recessive condition. What is the probability that Sheila is a carrier?
1) 0.5
2) 0.75
3) 0.125
4) 0.25
5) 0.66

Answer 1

1 becuase becuase becuase

Answer 2

To determine the probability that Sheila is a carrier of cystic fibrosis, we need to consider the genetic inheritance patterns of the condition.

Cystic fibrosis is an autosomal recessive condition, which means that both parents must carry at least one copy of the mutated gene for their child to be affected. If both Paula and Jerome have a mother who is affected by cystic fibrosis, it means that they are both carriers of the mutated gene.

When two carriers have a child, there is a 25% chance that the child will inherit two copies of the mutated gene and be affected by cystic fibrosis, a 50% chance that the child will inherit one copy of the mutated gene and be a carrier like their parents, and a 25% chance that the child will inherit two normal copies of the gene and not be a carrier.

Therefore, the probability that Sheila is a carrier is 0.5 or 50%.

So, the correct answer is option 1) 0.5.