Which statement about cystic fibrosis is true?(1 point)

Question

Responses

Carriers have an advantage over people who do not have the cystic fibrosis mutation.
Carriers have an advantage over people who do not have the cystic fibrosis mutation.

Cystic fibrosis affects a person's ability to make normal red blood cells.
Cystic fibrosis affects a person's ability to make normal red blood cells.

Cystic fibrosis is caused by a mutation in which a dominant allele replaces a recessive allele.
Cystic fibrosis is caused by a mutation in which a dominant allele replaces a recessive allele.

Cystic fibrosis is caused by a deletion of one codon in the DNA molecule.

Answer 1

The true statement about cystic fibrosis is:

Carriers have an advantage over people who do not have the cystic fibrosis mutation.

Carriers of the cystic fibrosis gene mutation (CFTR) may have some resistance to certain bacterial infections, such as those caused by Vibrio cholerae, which provided a selective advantage in certain environments.

The other statements are incorrect:

• Cystic fibrosis primarily affects the lungs and digestive system, not the ability to make normal red blood cells.
• Cystic fibrosis is caused by a mutation in a recessive allele, not by a dominant allele replacing a recessive allele.
• Cystic fibrosis is typically caused by a deletion of three nucleotides, leading to the loss of the amino acid phenylalanine in the CFTR protein, rather than a deletion of one codon.