Which of the following statements describes a nonsense mutation?
o
a. a single base in either dna or mrna is replaced with the wrong
base but codes for the same amino acid.
o
b. a single base in either dna or mrna is replaced with the wrong
base, producing a stop codon.
o
c. a single codon is replaced with a different codon, causing the
wrong amino acid to attach to the chain.
o
d. a single base in either dna or mrna is deleted or inserted,
causing protein synthesis to stop early.