A dideoxynucleotide does not contain: (A) 2' & 3' OH group, (B) 3' & 4' OH group, (C) 4' & 5' OH group, (D) 2' & 5' OH group
Answer is A. Dideoxy nucleotide Lacks 3' OH group also. Stop the chain elongation when they are incorporated. DNA polymerase requires 3' OH group to begin polymerisation. Use: Sanger chain termination method of DNA sequencing. Didanosine is a dideoxynucleotide used in the therapy of HIV.