Amutagen is 1: a living thing that has undergone a mutation. 2: an agent that causes a mutation in dna. 3: a mutation that has affected one gene. 4: a chemical that can poison living cells.
Which kind of mutation has occurred when the codon for an amino acid is changed to a stop codon? a. a silent mutation b. a missense mutation c. a frameshift mutation d. a nonsense mutation