Vertebrates and invertebrates
The function of a protein is determined by its shape. The shape of a protein is determined by its primary structure (sequence of amino acids). The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene (DNA) encoding it.
is that what you were asking about?
The answer is; A
There is no such RNA as endoplasmic RNA. After transcription, the mRNA form an initiation complex with ribosomes and tRNA. The tRNA brings in amino acids based on the sequence of codons on the mRNA. The amino acids are bonded together in chains to form a polypeptide.