Which statement about cystic fibrosis is true?
Carriers have an advantage over people who do not have the cystic fibrosis mutation.
Cystic fibrosis is caused by deletion of one codon in the DNA molecule.
Cystic fibrosis is caused by mutation in which a dominant allele replaces a reverses allele.
Cystic fibrosis affect a persons ability to make normal red blood cells.