<prompt> Which of the following is NOT seen in DNA:CytosineAdenineGuanineUracil  <response>: Ans. d Uracil Uracil is present in RNA. Nitrogen base pairs present in RNA: Adenine, Guanine, Uracil, CytosineStructure of DNA Double helix, right handed, anti-parallel to each other Two strands of DNA are held together with help of hydrogen bonds 2 hydrogen bonds between A T 3 hydrogen bonds between G C 6 types of DNA have been described: A, B, C, D, E, Z Z is left handedImportant differences between DNA types:Types of DNANo. of base pairs per turnsPhysical characterOrientationA-DNA11Short and broadRight handedB-DNA MC form10.5Long and thinRight handedZ-DNA12Elongated and thinLeft handed 