Question

many different types of mutations can occur within the body. cystic fibrosis is a genetic disorder that is caused by different mutations within the cftr gene. one mutation in the cftr gene that leads to cystic fibrosis causes translation to end earlier in the gene sequence. which type of mutation causes this translation error that leads to cystic fibrosis?
○ silent
○ missense
○ nonsense
○ deletion

Explanation:

• A silent mutation changes the DNA sequence but does not change the amino - acid sequence (due to the degeneracy of the genetic code), so it does not cause translation to end early.
• A missense mutation changes one amino - acid in the protein sequence. It does not cause premature termination of translation.
• A nonsense mutation changes a codon that specifies an amino - acid into a stop codon. This causes translation to terminate prematurely.
• A deletion mutation involves the loss of one or more nucleotides. While it can disrupt the reading frame (if not in multiples of 3) and lead to a non - functional protein, it is not specifically defined by causing premature translation termination like a nonsense mutation.

Answer:

nonsense