rna often are made of one sequence of nucleotides
rna_strand is polynucleotide_strand. nucleobase is rna. rna_molecule is not polynucleotide_strand. rna_molecule is rna. rna_strand is not polynucleotide_strand. rna is polymer. nucleobase is not rna. rna_molecule is polynucleotide_strand. rna_enzyme is rna_molecule. rna_molecule is rna_strand.