Question

two mutations of a genetic sequence are shown. a dna codon chart is also shown.
original sequence:
3-tac ccg ata ggc cac-5
mutation 1:
3-tac ccg aaa ggc cac-5
mutation 2:
3-tac ccg aa ggc cac-5

• which mutation would have the most significant impact on the gene product?
• why would the impact be so significant?

Explanation:

Mutation 2 is a frameshift mutation. Frameshift mutations occur when nucleotides are inserted or deleted, changing the reading frame of the genetic code. This affects all subsequent codons and thus all subsequent amino acids in the protein. Mutation 1 is a point mutation (substitution). Point mutations change only one codon. If the original codon (ATA) and the mutated codon (AAA) code for different amino acids, it's a missense mutation. But even so, only one amino acid is affected. A frameshift (Mutation 2) disrupts the entire downstream sequence of amino acids, likely leading to a non - functional protein.

Answer:

• Mutation 2 would have the most significant impact.
• Because it is a frameshift mutation. Frameshift mutations change the reading frame, affecting all subsequent codons and amino acids, while mutation 1 (a point mutation) only affects one codon (and potentially one amino acid if it's a missense mutation).