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

Answer 1

The true statement about cystic fibrosis from the provided options is:

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

This is because individuals who are carriers (heterozygous for the CFTR gene mutation) may have some level of protection against certain illnesses, such as cholera or typhoid fever, which is thought to have provided a selective advantage in certain populations.

The other statements are incorrect:

• Cystic fibrosis is caused by mutations in the CFTR gene, specifically a recessive allele, not a dominant one.
• The most common mutation, ΔF508, is actually a deletion of three nucleotides (which codes for one amino acid), not a deletion of one codon.
• Cystic fibrosis primarily affects the respiratory system and digestive system, not the production of red blood cells.