nucleotide is a kind of repeating unit in dna and rna
polynucleotide is not nucleotide. nucleotide is monomer. nucleotide is molecule. ribonucleotide is nucleotide. nucleobase is rna. polynucleotide is nucleotide. oligonucleotide is nucleotide. adenine_nucleotide is nucleotide. dna_molecule_nucleotide is nucleotide. rna_molecule is polynucleotide_strand.