Question

assignment active
learning about cystic fibrosis
read the article and use the information to answer the following questions.
cystic fibrosis
cystic fibrosis is genetic, meaning it can be passed from parent to child. what type of mutation causes cystic fibrosis?

• somatic mutation
• germline mutation
• silent mutation

done
if both parents are carriers of the defective cf gene, what is the chance that their child will have cystic fibrosis?

• 0%
• 25%
• 50%
• 100%

done

Explanation:

Cystic fibrosis is a genetic disorder. Germline mutations are mutations in the reproductive cells (sperm and egg) and can be passed from parents to offspring. When both parents are carriers (heterozygous) of the defective CF gene (let's assume the normal allele is \(A\) and the defective allele is \(a\), so parents have genotype \(Aa\)). Using a Punnett square:

Gametes of Parent 1	Gametes of Parent 2
\(A\)	\(AA\)	\(Aa\)
\(a\)	\(Aa\)	\(aa\)

The probability of getting \(aa\) (child with cystic fibrosis) is \(\frac{1}{4}=25\%\).

Answer:

For the mutation type: germline mutation.
For the probability of child having cystic fibrosis: 25%.