A Level Biology Practice Exam

What role does the waxy cuticle play in plant health?

1. It enhances photosynthesis by capturing light

2. It prevents water from evaporating

3. It serves as a passive defense against pathogens

4. It promotes nutrient absorption from the soil

The correct answer is: It serves as a passive defense against pathogens

The waxy cuticle is a significant structure found on the surfaces of aerial parts of plants, primarily leaves and stems. Its primary role is to prevent water loss through evaporation. This is particularly crucial for plants as they need to maintain water levels, especially in environments where water availability may be limited. The cuticle acts as a barrier, reducing transpiration rates and thereby conserving water within the plant tissues, which is essential for overall health and physiological processes. While it may also contribute to other functions, such as providing some level of defense against pathogens, its most recognized and critical function pertains to water retention. Therefore, the waxy cuticle primarily ensures that plants can survive in varying environmental conditions by minimizing water loss, which is vital for maintaining their health and function.