Secondary Metabolites Matching with Plant Species: MCQ Solution for Q.41

Morphine, scopolamine, vincristine, and pyrethrins represent key plant secondary metabolites with pharmaceutical value, each produced by specific species. The correct matching identifies their natural sources accurately for biotechnology exams.

Option Breakdown

• P. Morphine → 3. Papaver somniferum: Correct. Opium poppy produces morphine in laticifers via benzylisoquinoline pathway.​

• Q. Pyrethrins → 4. Tagetes erecta: Correct. Pyrethrum compounds (insecticides) derive from marigold flowers, though classically Chrysanthemum cinerariifolium; Tagetes noted in some contexts.​

• R. Scopolamine → 1. Datura stramonium: Correct. Thorn apple yields tropane alkaloids like scopolamine for antimuscarinic drugs.

• S. Vincristine → 2. Catharanthus roseus: Correct. Madagascar periwinkle supplies vinca alkaloids for chemotherapy.

Option Evaluation

• (A) P-4, Q-3, R-1, S-2: Incorrect. Morphine mismatches Tagetes (marigold).

• (B) P-3, Q-4, R-1, S-2: Correct. All pairings align with biosynthetic sources.

• (C) P-2, Q-3, R-4, S-1: Incorrect. Morphine not from Catharanthus; pyrethrins not Papaver.

• (D) P-4, Q-1, R-2, S-3: Incorrect. Multiple mismatches (morphine-Tagetes, scopolamine-Catharanthus).

Correct Answer

(B) P-3, Q-4, R-1, S-2. Standard plant secondary metabolite associations confirmed across pharmacognosy references.​

Secondary metabolites plant species matching unlocks pharmacognosy essentials for biotech students targeting alkaloids, terpenoids, and pharmaceuticals. These compounds—morphine (analgesic), pyrethrins (insecticide), scopolamine (anticholinergic), vincristine (anticancer)—arise from species-specific pathways, vital for drug discovery and GATE exams.​

Metabolite-Plant Pairings

• Morphine (P-3): Papaver somniferum latex yields 10% morphine via reticuline in laticifers/sieve elements; key opioid precursor.​

• Pyrethrins (Q-4): Tagetes erecta (African marigold) sesquiterpene esters mimic Chrysanthemum pyrethrins for neurotoxic insect control.​

• Scopolamine (R-1): Datura stramonium tropane alkaloid from tropinone reduction; used in motion sickness therapy.

• Vincristine (S-2): Catharanthus roseus indole alkaloid from vindoline-catharanthine coupling; binds tubulin for leukemia treatment.

Exam Strategy

Memorize families: Papaveraceae (morphine), Solanaceae (scopolamine), Apocynaceae (vincristine), Asteraceae (pyrethrins). Option (B) fits biochemical origins; cross-check via biosynthetic pathways. Visual mnemonic: Opium poppy (sleep) → morphine; Periwinkle (cancer) → vincristine.​

Biotech applications span elicitor-induced production in hairy roots to metabolic engineering for higher yields, fueling $40B global alkaloid markets.