AP BIOLOGY

Detailed explanation-1: -The codon for Methionine; the translation initiation codon. Usually, protein translation can only start at a Methionine codon (although this codon may be found elsewhere within the protein sequence as well). In eukaryotic DNA, the sequence is ATG; in RNA it is AUG.

Detailed explanation-2: -The enzyme that converts DNA into mRNA is called RNA polymerase, which attaches to the DNA double helix as shown here. Once attached, RNA polymerase can unwind the helix and begin copying one of the DNA strands to form an mRNA transcript of the gene.

Detailed explanation-3: -The CGA codon is one of six arginine‐encoding codons, as shown in the standard genetic code. In Saccharomyces cerevisiae, CGA is a rare codon decoded by arginyl‐tRNAICG, which is biosynthesized by deamination of the wobble position adenine of tRNAACG 1.

Detailed explanation-4: -mRNA codons are read from 5’ to 3’, and they specify the order of amino acids in a protein from N-terminus (methionine) to C-terminus. The mRNA sequence is: 5’-AUGAUCUCGUAA-5’