Two carriers of cystic fibrosis, an autosomal recessive condition, have a child. What is the probability that the child has the disorder?
Answer and explanation
Correct answer: C. 25%
- Step 1: Two carriers (Cc x Cc) produce a child with cc in one of four equally likely combinations.
Answer
25%.
Why not the others: 50%, 75% and 100% don't fit.
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