Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.
1. translation of an RNA nucleotide sequence into a sequence of amino acids
2. linking of nucleotides to form a polypeptide
3. removal of introns from RNA and the stitching together of exons
4. translation of a DNA nucleotide sequence into a sequence of amino acids
5. transferring of information from DNA to messenger RNA