If DNA percentage of thymine is 20. What is the percentage of guanine?                         [2002]

1. 20%

2. 40%

3. 30%

4. 60%

Two free ribonucleotide units are interlinked with

1. Peptide bond

2. Covalent bond

3. Hydrogen bond

4. Phosphodiester bond

All of the following are nucleosides, except:

Which of the following biomolecules does have a phosphodiester bond?

(1) Fatty acids in a diglyceride

(2) Monosaccharides in a polysaccharide

(3) Amino acids in a polypeptide

(4) Nucleic acids in a nucleotide

Given below is the diagrammatic representation of one of the categories of small

molecular weight organic compounds in the living tissues. Identify the category shown

and the one blank component X in it

Category              Component

1. Cholesterol       Guanin

2. Amino acid       NH₂

3. Nucleotide        Adenine

4. Nucleoside       Uracil

Which one of the following structural formulae of two organic compounds is correctly

identified with its related function?

1. A - triglyceride major - a source of energy

2. A - Lecithin - a component of cell membrane 

3. B - Adenine - forms nucleotides of the nucleic acids

4. Both 2. and 3.

Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched

with the category mentioned against it?

1. Thymine, Uracil         - Pyrimidines

2. Uracil, Cytosine         - Pyrimidines

3. Guanine, Adenine      - Purines

4. Adenine, Thymine     - Purines

The linkage that joins two adjacent nucleotides in RNA is

1. phosphate ester                 

2. phosphodiester

3. phosphate anhydride         

4. N-glycoside

Phosphodiester bond is present in

1. ATP

2. ADP

3. cAMP

4. none of these

In RNA thymine is replaced by

1. uracil                           

2. adenine

3. thiamine                       

4. guanine