The use of stem tightener is to prevent | Agrigyan

• Comparative Water Use Efficiency (WUE):
• CAM Plants: Open stomata strictly at night, minimizing transpirational water loss; achieve the highest WUE ($100 - 200\text{ g } H_2O/\text{g DM}$).
• $C_4$ Plants: Possess Kranz anatomy and PEPCase, maintaining high photosynthesis at low stomatal conductance ($250 - 350\text{ g } H_2O/\text{g DM}$).
• $C_3$ Plants: Exhibit high photorespiration and open stomata, requiring $500 - 800\text{ g } H_2O/\text{g DM}$ (lowest WUE).
• Sequence of Decreasing WUE: CAM > C4 > C3. (Correct answer: Option 1)

• Biological Nitrification Pathway:
• Step 1: Oxidation of ammonium into nitrite:

• Step 2: Oxidation of nitrite into nitrate:

• Conclusion: Chemoautotrophic Nitrosomonas bacteria are specifically responsible for converting ammonia/organic nitrogen into nitrites. (Correct answer: Option 3)

• Non-Timber Forest Products (NTFPs) and Minor Forest Produce (MFP):
• Fibres: Extracted from bast bark of Grewia oppositifolia (Bhimal), widely utilized for cordage and ropes in the western Himalayas $\rightarrow$ (I)
• Essential / Grass Oil: Distilled from leaves of Cymbopogon flexuosus (East Indian Lemongrass) to yield citral-rich essential oil $\rightarrow$ (II)
• Vegetable Butter / Fat: Extracted from seed kernels of Garcinia indica (Kokam), yielding kokam butter used in confectionery and cosmetics $\rightarrow$ (III)
• Natural Fruit Dye: Red powdery glandular pubescence harvested from fruit capsules of Mallotus philippensis (Kamala tree), producing yellow-orange silk dye $\rightarrow$ (IV)
• Systematic Match: (A)-(I), (B)-(II), (C)-(III), (D)-(IV) corresponds to Option 1.

Correct option: (1) (A) - (II), (B) - (1), (C) - (I), (DB) - (IY).