Question

question 6 of 10 a part of an mrna has the sequence aga. use the table below to figure out which amino acid is coded for by aga, then use the table to figure out which change to this sequence would indicate a silent mutation. messenger rna codons first base in codon second base in codon third base in codon u c a g u uuu uuc phe ucu ucc uca ucg ser uau uac tyr ugu ugc cys u uua uug leu uaa stop uag stop uga stop ugg trp c c cuu cuc cua cug leu ccu ccc cca ccg pro cau cac his cgu cgc cga cgg arg a a auu auc aua lie acu acc aca acg thr aau aac asn agu agc ser g g guu guc gua gug val gcu gcc gca gcg ala gaa gag glu ggu ggc gga ggg gly a. agg b. gag

Explanation:

Step1: Understand silent mutation

A silent mutation is a change in the DNA or mRNA sequence that does not result in a change in the amino - acid sequence.

Step2: Find amino - acid for AGA

Looking at the mRNA codon table, the codon AGA codes for the amino - acid Arginine (Arg).

Step3: Check each option

• For option A (AGG): The codon AGG also codes for Arginine (Arg). So, a change from AGA to AGG is a silent mutation as the amino - acid remains the same.
• For option B (GAG): The codon GAG codes for Glutamic acid (Glu). A change from AGA to GAG would result in a different amino - acid, so it is not a silent mutation.

Answer:

A. AGG