DNA Polynucleotide Chain Structure — NEET Biology
📚 Practice ConceptSimilarly, at the other end of the polymer the sugar has a free OH of 3'C group which is referred to as 3'-end of the polynucleotide chain. The backbone of a polynucleotide chain is formed due to sugar and phosphates. The nitrogenous bases linked to sugar moiety project from the backbone.
Which of the following statements are NOT correct regarding the structure and stability of DNA? S1. The two polynucleotide chains of DNA run antiparallel to each other, one in 5′→3′ direction and the other in 3′→5′ direction. S2. The backbone of the DNA strand is formed by nitrogenous bases and phosphate groups. S3. Stacking of one base pair over another, along with hydrogen bonding, contributes to the stability of the DNA double helix. S4. In a double-stranded DNA molecule, adenine pairs with uracil and guanine pairs with cytosine. S5. DNA is less stable than RNA due to the presence of a reactive 2′-OH group on the sugar moiety.
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