Grass leaf adaptations for water conservation in dry habitats

Steps:

• Examine photomicrograph features: hair-like structures (trichomes) on leaf surface and rolled leaf shape in transverse section.
• Recall trichome function: they trap moist air, increasing external humidity in the boundary layer to reduce transpiration.
• Recall leaf shape function: rolled form minimizes exposed surface area, decreasing water loss and increasing internal humidity.
• Match to option C, which correctly pairs these roles for arid adaptation.

Why C is correct:

• Trichomes increase external humidity by slowing air movement (boundary layer effect), while rolled leaves increase internal humidity by reducing evaporation per Fick's law of diffusion.

Why the others are wrong:

• A: Hairs do not decrease humidity; leaf shape affects internal, not external.
• B: Neither feature primarily increases internal humidity via the described mechanisms.
• D: Features conserve water by increasing, not decreasing, humidities.

Final answer: C