Question

cystic fibrosis is a genetic disease in which the cftr protein is abnormally short and does not function properly. as a result, the body makes a thick, sticky mucous instead of thin, watery mucous. what type of mutation causes this disease? inherited silent mutation insertion mutation caused by a dna replication error mutagen - caused translocation mutation inherited nonsense mutation mutagen - caused missense mutation

Explanation:

Cystic fibrosis is a genetic disorder, so it is inherited. A nonsense mutation introduces a premature stop codon, resulting in a truncated (abnormally short) protein. In cystic fibrosis, the CFTR protein is affected in this way. A silent mutation would not change the protein structure (so the first option is wrong). Insertion mutations (second option) cause frameshifts which usually lead to more widespread disruptions rather than just a short - ened protein. Translocation mutations (third option) involve the rearrangement of parts of non - homologous chromosomes and are not the cause here. Mutagen - caused mutations (fifth option) are not the case as cystic fibrosis is genetic (inherited), not caused by mutagens in the environment. A missense mutation (fifth option) changes one amino acid to another, not making the protein abnormally short. A nonsense mutation is the correct cause as it leads to a prematurely terminated (short) non - functional protein.

Answer:

inherited nonsense mutation