Question

In a DNA molecule ______.

विकल्प

• bases are hydrogen-bonded to one another.

• sugars are covalently bonded to the phosphates.

• bases are covalently bonded to the sugars.

• all of the above.

Answer 1

all of the above.

Explanation:

A DNA molecule is held together by a combination of strong and weak chemical bonds that ensure its stability and function. The nitrogenous bases (A, T, G, and C) are connected to one another across the two strands by hydrogen bonds, which are weak enough to allow the strands to “unzip” during replication. Within the structural backbone of each strand, the sugar (deoxyribose) and phosphate groups are linked by strong covalent phosphodiester bonds, creating a durable outer chain. Additionally, each nitrogenous base is itself covalently bonded to its respective sugar molecule via a glycosidic bond, forming the individual nucleotide subunits that make up the entire polymer.