Question

1. use the table to answer the question below.

dna codes for amino acids
amino acids | dna codons
ala | cga, cgg, cgc
arg | gca, gcg, gct
his | gta, gtg
iso | taa, tag, tat
leu | aat, aac, gaa
met (start codon) | tac
thr | tga, tgg, tgt
tyr | ata, atg
which of the following mutations would change the amino acid sequence of a protein?
aat mutated to gaa
taa mutated to aat
ata mutated to atg
gta mutated to gtg

Explanation:

Step 1: Analyze each mutation

• For "AAT mutated to GAA": AAT codes for Leu, GAA also codes for Leu (from table: Leu has codons AAT, AAC, GAA). So no change.
• For "TAA mutated to AAT": TAA codes for Iso, AAT codes for Leu. Different amino acids, so this mutation changes the sequence.
• For "ATA mutated to ATG": ATA and ATG both code for Tyr (from table: Tyr has codons ATA, ATG). No change.
• For "GTA mutated to GTG": GTA and GTG both code for His (from table: His has codons GTA, GTG). No change.

Answer:

TAA mutated to AAT