<P> In transcription , the codons of a gene are copied into messenger RNA by RNA polymerase . This RNA copy is then decoded by a ribosome that reads the RNA sequence by base - pairing the messenger RNA to transfer RNA , which carries amino acids . Since there are 4 bases in 3 - letter combinations , there are 64 possible codons ( 4 combinations ) . These encode the twenty standard amino acids , giving most amino acids more than one possible codon . There are also three ' stop ' or ' nonsense ' codons signifying the end of the coding region ; these are the TAA , TGA , and TAG codons . </P>
<P> In transcription , the codons of a gene are copied into messenger RNA by RNA polymerase . This RNA copy is then decoded by a ribosome that reads the RNA sequence by base - pairing the messenger RNA to transfer RNA , which carries amino acids . Since there are 4 bases in 3 - letter combinations , there are 64 possible codons ( 4 combinations ) . These encode the twenty standard amino acids , giving most amino acids more than one possible codon . There are also three ' stop ' or ' nonsense ' codons signifying the end of the coding region ; these are the TAA , TGA , and TAG codons . </P>
the section of dna being used to make the strand of rna is known as
the section of dna being used to make the strand of rna is known as
a gene
a gene