What quality of submerged plants enhances their uptake of pesticides?

• A. Thick Outer Epidermis
• B. Very Thin Epidermis
• C. Dense Waxy Cuticle
• D. No Epidermis

Answer: (B)

Uptake of pesticides by submerged plants mainly depends on how easily the chemical can diffuse across the outer surface into the tissues. A very thin epidermis offers far less diffusion resistance than a thicker layer or a dense waxy cuticle, so pesticides dissolved in water can move into the plant more readily. In contrast, a thick epidermis or a dense cuticle acts as a barrier and slows entry. While having no epidermis would theoretically remove that barrier entirely, the exam focuses on how reducing the barrier thickness increases uptake, making a very thin epidermis the best explanation.