Read the following biomolecule-category pairs carefully: (A) Uridine - Nitrogenous base (B) Adenylic acid - Nucleotide (C) Morphine - Alkaloid (D) Carotenoids - Pigment (E) Ricin - Drug How many of the above pairs are correctly matched?

Step-by-step solution

Let us evaluate each pair based on the classification of biomolecules: (A) Uridine is a nucleoside (uracil attached to a ribose sugar), not a nitrogenous base. The nitrogenous base itself is uracil. (Incorrect) (B) Adenylic acid has a phosphate group esterified to the sugar of adenosine, making it a nucleotide. (Correct) (C) Morphine is classified as an alkaloid. (Correct) (D) Carotenoids are classified as pigments. (Correct) (E) Ricin is classified as a toxin, whereas drugs include compounds like vinblastin and cu