When grown in a greenhouse, the leaves of Aloe nobilis are green. When found in the desert in the wild, however, the leaves are often red. What BEST explains this observation?

Answer 1

The best explanation for this observation is that the red color of Aloe nobilis leaves in the wild acts as a protective adaptation against environmental stressors. In the desert, the plant is exposed to intense levels of sunlight, high temperatures, and limited water availability. The red coloration of the leaves is due to the presence of pigments like anthocyanins, which provide protection against excessive sunlight and UV radiation. The red color can also act as camouflage, blending in with the surrounding environment and providing some protection against herbivores. In contrast, when grown in a greenhouse, Aloe nobilis is sheltered from these extreme conditions, so the leaves do not need the red pigmentation for survival.