Answer:A) a mutation that changes a codon to stop codon is nonsense mutation
B) a mutation that does not change the amino acid is silent mutation
C) a mutation that involves the addition or deletion of a nucleotide that results in a shift in the reading frame is frameshift mutation
D) a mutation that changes an amino acid is missense mutation
Explanation: A nonsense mutation is a type of mutation in which a change in one nucleotide sequence in a DNA produces a stop codon in an mRNA sequence. The stop codon signals the termination of protein synthesis.
A silent mutation is a type of mutation in which a change in the nucleotide sequence of a DNA produces a codon on the mRNA that codes for the same amino acid as the original codon. This results in the production of a protein with the same amino acid sequence as the original protein.
A frameshift mutation is a type of mutation in which an addition or deletion of a nucleotide alters the reading frame of the mRNA codons. Codons are read in triplets, therefore a deletion or insertion of one or more nucleotides to the DNA sequence will produce an mRNA with a reading frame different from the original mRNA. This will lead to incorporation of wrong amino acids from the point of mutation to the end of the reading frame and will result in production of a nonfunctional protein.
A missense mutation is a type of mutation in which a change in a single nucleotide in a DNA sequence produces a different codon on the mRNA that codes for an amino acid different from that of the original codon. A missense mutation results in the production of a protein with a different amino acid sequence.