28. Given below are the list of plant derived alkaloids and their uses in modern medicine.
    Alkaloids                     Uses
    A. Caffeine                i. Antineoplastic used to
    treat leukemia and
    other cancers
    B. Morphine            ii. Traditional anti-
    malaria agent
    C. Quinine               iii. Powerful Narcotic
    analgesic
    D. Vincristine         iv. Widely used central
    nervous syntem
    stimulant

    Which one of the following options represents all correct matches ?
    (1) A (iii) B (iv) C(ii) D(i)
    (2) A (iii) B (iv) C(i) D(ii)
    (3) A (iv) B (i) C(iii) D(ii)
    (4) A (iv) B (iii) C(ii) D(i)

    Correct answer: (4) A (iv) B (iii) C (ii) D (i)

    Explanation:

    • (A) Caffeine is a widely used central nervous system stimulant, commonly found in coffee and tea, and stimulates alertness and wakefulness. So, A matches iv.

    • (B) Morphine is a powerful narcotic analgesic used to relieve severe pain, derived from opium poppy. Hence, B matches iii.

    • (C) Quinine is a traditional antimalarial agent from Cinchona species. So C matches ii.

    • (D) Vincristine is an antineoplastic drug used to treat leukemia and other cancers, isolated from Catharanthus roseus. So D matches i.

    Option-wise:

    • (1) Incorrect because A (iii) and B (iv) are reversed.

    • (2) Incorrect for same reasons.

    • (3) Incorrect because B and C are mismatched.

    • (4) Correct: A (iv), B (iii), C (ii), D (i).

Plant-derived alkaloids play diverse therapeutic roles: caffeine stimulates the nervous system, morphine serves as a potent analgesic, quinine fights malaria, and vincristine functions as a chemotherapy drug against cancers like leukemia.