Final answer:
In a hot desert environment, the dense layer of spines or hairs on plants creates a thick boundary layer of still air that can cause overheating due to a reduction in water loss through transpiration.option b is correct answer.
Step-by-step explanation:
In a hot desert environment, a dense layer of spines or hairs, known as trichomes, can create a thick boundary layer of still air near a plant's surface. This boundary layer would have deleterious effects on the plant because it could reduce water loss through transpiration. While retaining water may seem advantageous, in a hot desert, it is equally important to enhance evaporative cooling to prevent overheating.
These adaptations—thick waxy cuticles, sunken stomata, and trichomes—are tailored to minimize water loss, which is critical for desert plants, otherwise known as xerophytes, to survive in arid conditions where water is limited.However, the same adaptations that limit water loss can also lead to overheating, as the boundary layer of air becomes a barrier to heat exchange with the surrounding environment.
Thus, while these traits are beneficial in preventing water loss, they would not be advantageous in a desert environment where plant temperature regulation is also critical, answering the question by indicating that trichomes would reduce water loss through transpiration (option b), which is not beneficial in extreme heat as it would lead to overheating.