AP BIOLOGY

Detailed explanation-1: -Two successive nucleotides of DNA are joined by phosphodiester linkage in which the 5’-phosphate group of one nucleotide unit is joined to the 3’-hydroxyl group of the next nucleotide. Thus, phosphate and pentose sugars of DNA are joined by phosphodiester linkage; the correct answer is B.

Detailed explanation-2: -The pentose sugar For example, the phosphate residue is attached to the 5′ carbon of the sugar and the hydroxyl group is attached to the 3′ carbon of the sugar.

Detailed explanation-3: -In a nucleotide, the sugar occupies a central position, with the base attached to its 1′ carbon and the phosphate group (or groups) attached to its 5′ carbon.

Detailed explanation-4: -(D) The five prime end of DNA is the one with the ribose sugar. DNA is a biological macromolecule that carries the genetic information. It is made up of two strands that wrap around each other to form the double helix shape, as shown here.

Detailed explanation-5: -The sugar is the 3’ end, and the phosphate is the 5’ end of each nucleiotide. The phosphate group attached to the 5’ carbon of the sugar on one nucleotide forms an ester bond with the free hydroxyl on the 3’ carbon of the next nucleotide.