When the conditions are dry, a grass leaf curls inward to minimize water loss due to the presence of

• A. Thick cuticle
• B. Large xylem cavities
• C. Parallel venation
• D. Bulliform cells

When conditions are dry, grass leaves curl inward primarily due to the presence of Bulliform cells. These specialized cells help the leaf reduce its surface area, which minimizes water loss through transpiration.

Understanding Bulliform Cells

Bulliform cells are located on the upper side of grass leaves. They are large and can change shape based on water availability:

• When water is abundant, these cells remain turgid, keeping the leaf flat.
• In dry conditions, they lose water, causing the leaf to fold and conserve moisture.

Other Features of Grass Leaves

While other features like a thick cuticle and parallel venation play roles in water retention and structural support, it is the bulliform cells that are specifically responsible for the curling action during drought.