Which adaptation would decrease water loss from a plant in a region low rainfall? (A) Broad leaves (B) Surface roots (C) Sunken stomates (D) Loosely packed epidermal cells - HSC - SSCE Biology - Question 3 - 2015 - Paper 1

To address the issue of water loss in plants, particularly in regions with low rainfall, it's crucial to consider the structural adaptations of plants that minimize transpiration. Among the options presented:

1. Broad leaves (A): While broad leaves can increase photosynthesis by capturing more sunlight, they also increase the surface area for transpiration, potentially leading to more water loss.

2. Surface roots (B): Surface roots may absorb water from light rains but do not directly address water loss through transpiration.

3. Sunken stomates (C): Sunken stomates are a significant adaptation for reducing water loss. By being located deeper in the leaf surface, they are less exposed to air currents, which minimizes evaporation. This adaptation is crucial for plants in arid environments.

4. Loosely packed epidermal cells (D): Loosely packed cells can create spaces that may retain moisture but do not specifically reduce water loss effectively like sunken stomates.

Given these considerations, the best adaptation to decrease water loss from a plant in a region with low rainfall is (C) Sunken stomates.