Q57. Match the following
| Group I | Group II | Group III |
|---|---|---|
| P. Sorghum Q. Castor R. Mushroom S. Cotton |
1. Gossypol 2. Strychnine 3. Dhurrin 4. Bungarotoxin 5. Ricin 6. α-Amanitin |
i. Protein ii. Glycosidic conjugate iii. Alkaloid iv. Polyphenol v. Lipid vi. Cyclic peptide |
Correct Answer: (A) P-3-ii, Q-5-i, R-6-vi, S-1-iv
Sorghum contains dhurrin, a cyanogenic glycoside. Castor produces ricin, a toxic protein. Mushroom has α-amanitin, a deadly cyclic peptide toxin. Cotton seeds yield gossypol, a polyphenolic compound.
Matching Breakdown
P. Sorghum – 3. Dhurrin (ii. Glycosidic conjugate)
Dhurrin is a cyanogenic glycoside in sorghum that releases hydrogen cyanide upon hydrolysis, acting as a plant defense. This fits “glycosidic conjugate” precisely.
Q. Castor – 5. Ricin (i. Protein)
Ricin from castor beans is a ribosome-inactivating protein toxin, inhibiting protein synthesis. It matches the protein category directly.
R. Mushroom – 6. α-Amanitin (vi. Cyclic peptide)
α-Amanitin, from Amanita mushrooms, is a bicyclic octapeptide that blocks RNA polymerase II, causing fatal liver damage. It is a classic cyclic peptide.
S. Cotton – 1. Gossypol (iv. Polyphenol)
Gossypol is a yellow polyphenolic aldehyde in cottonseeds, with sesquiterpenoid structure, known for toxicity and male contraceptive effects. Though lipid-like, it aligns with polyphenol classification here.
Option Analysis
Option (A): Correct
P-3-ii (dhurrin-glycoside), Q-5-i (ricin-protein), R-6-vi (amanitin-peptide), S-1-iv (gossypol-polyphenol). All pairings match biochemical facts.
Option (B): Incorrect
P-2-iii wrongly assigns strychnine (strychnos alkaloid) to sorghum; Q-4-iv mismatches bungarotoxin (snake venom protein) with castor; R-1-ii errors gossypol as glycoside for mushroom; S-6-v unfit for cotton.
Option (C): Incorrect
P-2-vi wrongly links strychnine as cyclic peptide; Q-5-v mismatches ricin as lipid; R-1-iv errors gossypol for mushroom; S-6-ii unfit ricin as glycoside for cotton.
Option (D): Incorrect
P-2-i wrongly assigns strychnine as protein; Q-3-iii mismatches dhurrin as alkaloid; R-4-iv errors bungarotoxin as polyphenol; S-1-v unfit gossypol as lipid.
Plant toxins like dhurrin in sorghum, ricin in castor, α-amanitin in mushrooms, and gossypol in cotton are key for GATE Life Sciences. This matching question tests secondary metabolites classification—glycosidic conjugates, proteins, cyclic peptides, polyphenols—to build exam-ready knowledge.
Toxins and Classifications
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Dhurrin (Sorghum): Glycosidic conjugate releasing HCN for defense.
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Ricin (Castor): Protein toxin halting translation.
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α-Amanitin (Mushroom): Cyclic peptide inhibiting transcription.
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Gossypol (Cotton): Polyphenol with toxicity in seeds.
Exam Relevance
Ideal for GATE XL biochemistry section. Focus: Match Group I (plants) to Group II (toxins) and Group III (types). Option A is correct per standard biology texts.
