GATE XL 2026 Paper 1 — page 21

Questions 61–63 of 122. Imported answers require review unless explicitly marked reviewed.

Which of the following combinations of photosynthetic carbon cycle in plants, and its matched biochemical reaction is/are correct?

Your answerSelect all correct options. You can choose more than one.

C3 pathway: Ribulose 1,5-bisphosphate + CO₂ + H₂O → 2 3-phosphoglycerate

C2 pathway: 2 Glycolate + 2 O₂ → 2 glyoxylate + 2 H₂O₂

C4 pathway: 2 2-Phosphoglycolate + 2 H₂O → 2 glycolate + 2 Pᵢ

CAM pathway: Phosphoenolpyruvate + HCO₃⁻ → oxaloacetate + Pᵢ

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Choose the correct combination(s) of alkaloid, source plant, and their main commercial use.

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Vincrine – Catharanthus roseus – anticancer drug

Scopolamine – Hyoscyamus niger – anticholinergic drug

Cocaine – Conium maculatum – antimalarial drug

Pilocarpine – Eschscholzia californica – antidepressant drug

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Which of the following statements is/are correct about plant movement?

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Diaheliotropic refers to orienting the leaves perpendicular to the rays of the sun to maximize light interception.

Paraheliotropic refers to orienting the leaves parallel to the rays of the sun to minimize light interception.

Diaheliotropic refers to orienting the leaves parallel to the rays of the sun to minimize light interception.

Paraheliotropic refers to orienting the leaves perpendicular to the rays of the sun to maximize light interception.

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2026 · Paper 1