During translation, nucleotide base triplets (codons) in mRNA are read in sequence in the 5’ → 3’ direction along the mRNA. Amino acids are specified by the string of codons. What amino acid sequence does the following mRNA nucleotide sequence specify?

The question is incomplete, it lacks the mRNA sequence. The sequence is as follows:

5′−AUGGCAAG−3′

The answer is Met-Ala-Arg-Lys

Explanation:

Gene expression in living organisms involves the process of transcription and translation. Transcription is the synthesis of a complementary strand of mRNA from a DNA template while translation involves using the transcibed mRNA as a template to synthesize amino acid sequence (proteins).

In the RIBOSOME, where the synthesis of protein occurs, the mRNA nuceleotide sequence is read in a group of three nucleotides called CODON. Each codon specifies a particular amino acid. The collection of all codons is the genetic code. Hence, for a specific mRNA sequence that reads 5′−AUGGCAAG−3′. The nucleotides will be read three at a time starting with AUG which is a codon that encodes METHIONINE.

Next, GCA is a codon that encodes ALANINE

Next, AGA is a codon that encodes ARGININE

Finally, AAA is a codon that encodes LYSINE.

Hence, the amino acid sequence using the above mRNA sequence, will read: Met-Ala-Arg-Lys

the correct answer is b