Question

g) If the strand of DNA with the sequence GTA mutated to GTG, would this be a silent or missense mutation? Hint: Find the RNA for both sequences and check to see that they code for different amino acids.

Answer 1

Answer:

Silent mutation

Explanation:

The two types of mutations given in the question have different meanings. A missense mutation is a mutation that occurs where a codon is changed, and that results in a change in the amino acid it codes for (eg. changing AAA which codes for Lys, to AAC which codes for Asn).

A silent mutation occurs when a nucleotide is changed, but the overall expression of the amino acid does not change (eg. changing AAA to AAG, both codons code for Lys).

GTA mutating to GTG keeps the amino acid Valine. Both codons code for the same amino acid, so it is classified as a silent mutation.

Answer 2

Answer:

Silent mutation

Explanation:

1. Convert to RNA: GTA in DNA=CAU in RNA; GTG in DNA=CAC
2. Find amino acid for each one: CAU=Histamine; CAC-Histamine
3. Do the amino acids match? Yes. Therefore, this is a silent mutation.