What is the defining feature of a desert biome?

The defining feature of a desert biome is characterized by very little rainfall and poor nutrient soils. Deserts typically receive less than 250 millimeters of precipitation annually, which significantly influences the types of plants and animals that can survive in such harsh conditions. The lack of moisture leads to minimal vegetation, often consisting of drought-resistant species like cacti and succulents. Furthermore, the soils in desert regions are often sandy or rocky, resulting in low nutrient content, making it difficult for many typical plant species to thrive.

In contrast, other choices describe characteristics more aligned with different ecosystems. High elevation areas usually experience different climatic conditions and more consistent rainfall, which do not match the desert's dry environment. The presence of frequent snow and cold temperatures characterizes tundra or polar regions rather than deserts, which are defined by their arid conditions. Lastly, dense vegetation and high biodiversity are more indicative of tropical rainforests or temperate forests, again showing the stark contrast to the sparse life forms found in deserts.