Question

below is a partial dna sequence and a mutation to the same gene. original dna: ata gta ttg ctc cgg gag dna mutation: ata tat tcg tcc ggg ag identify the mutation and explain the effect it would have on protein synthesis. a this mutation is a deletion mutation resulting in a frameshift. this would result in a different reading of the codons following the mutation, causing a different translation from the original strand. the protein being created could be abnormally short or abnormally long and will most likely not be functional. b this mutation is a point mutation resulting from a base substitution. this would result in the different reading of the one codon affected by the mutation, causing the substitution of a different amino acid in an otherwise unaltered protein. c this mutation is a substitution mutation resulting in a frameshift. this would result in a different reading of the codons following the mutation, causing a different translation from the original strand. the protein being created could be abnormally short, abnormally long, and will most likely not be functional. d this mutation is an insertion mutation resulting in a frameshift. this would result in a different reading of the codons following the mutation, causing a different translation from the original strand. the protein being created could be abnormally short or abnormally long and will most likely not be functional.

Explanation:

• Deletion Mutation: In the given DNA sequences, the original DNA has 6 codons (each of 3 bases). The mutated DNA has lost a base (the last codon in original is GAG - 3 bases, in mutation it is AG - 2 bases). A deletion of a base (or bases not in multiples of 3) causes a frameshift.
• Frameshift Effect: Since codons are read in groups of 3, a frameshift (due to deletion here) changes the reading frame for all codons after the mutation site. This leads to a completely different amino - acid sequence from the point of mutation. The protein can be truncated (if a stop codon is introduced prematurely) or elongated (if the reading frame changes in a way that no stop codon is encountered in the usual place) and is likely non - functional.
• Analysis of other options:
• Option B: A point mutation (base substitution) changes only one codon. But here, the number of bases has changed (not just substitution), so it is not a point mutation.
• Option C: Substitution mutation does not change the number of bases. Here the number of bases has changed (deletion), so it is not a substitution mutation.
• Option D: Insertion mutation would add bases. But here bases are lost (deletion), so it is not an insertion mutation.

Answer:

A. This mutation is a deletion mutation resulting in a frameshift. This would result in a different reading of the codons following the mutation, causing a different translation from the original strand. The protein being created could be abnormally short or abnormally long and will most likely not be functional.