Question

Insertions and deletions that occur in multiples of three nucleotides:

a. cause nonsense mutations.
b. cause frameshift mutations.
c. add or delete amino acids to/from the normal polypeptide.
d. shorten chromosomes.
e. cause cancer.

Answer 1

Insertions and deletions in multiples of three nucleotides add or remove amino acids from proteins without causing frameshift mutations, but when not in multiples of three, they can result in frameshift mutations and nonfunctional proteins.

Step-by-step explanation:

Insertions and deletions that occur in multiples of three nucleotides generally add or delete amino acids to or from the normal polypeptide, maintaining the original reading frame. When insertions or deletions are not in multiples of three, this can lead to frameshift mutations, which disrupt the genetic code and alter the entire sequence of amino acids beyond the point of the mutation, resulting in nonfunctional proteins.

Notably, a deletion mutation, such as the one that leads to cystic fibrosis by the loss of three nucleotides, can result in the loss of a single amino acid, in this case, phenylalanine, from a protein. While insertions and deletions can cause significant genetic diseases, not all of them result in cancer or chromosome shortening, as these outcomes depend on specific details of the mutation and the genes affected.