Complete hydrolysis of DNA does not yield

Secondary alcohol

The correct answer is option 4. Secondary alcohol.

The complete hydrolysis of DNA involves breaking the bonds between its constituent molecules. DNA is composed of repeating units called nucleotides, and each nucleotide consists of a phosphate group, a deoxyribose sugar molecule, and a nitrogenous base.

Let us explore the components released during the hydrolysis of DNA:

1. Phosphoric Acid:
 The backbone of DNA is formed by the alternating sugar (deoxyribose) and phosphate groups. The phosphodiester bonds between these phosphate groups are broken during hydrolysis, leading to the release of phosphoric acid (H₃PO₄).

2. Pentose Sugar (Deoxyribose):
Deoxyribose is a pentose sugar that is part of the DNA structure. Hydrolysis of the glycosidic bonds between the deoxyribose sugar and the nitrogenous bases liberates the pentose sugar.

3. Nitrogen-Containing Compounds (Nitrogenous Bases):
DNA has four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). Hydrolysis releases these nitrogenous bases.

4. Secondary Alcohol:
DNA lacks a hydroxyl group at the 2' carbon of its deoxyribose sugar. In contrast, RNA, which is another nucleic acid, has a hydroxyl group at the 2' carbon of its ribose sugar. During the hydrolysis of DNA, a secondary alcohol is not released because there is no hydroxyl group at the 2' carbon.

In summary, the hydrolysis of DNA yields phosphoric acid, deoxyribose sugar, and nitrogen-containing compounds (adenine, thymine, cytosine, and guanine), but it does not yield a secondary alcohol. The absence of a hydroxyl group at the 2' carbon distinguishes the sugar structure of DNA from that of RNA.