Question

adaptations to cold temperatures have high metabolic costs. it is expensive, in terms of energy use, for land plants and animals to withstand very cold temperatures, and it gets more expensive the colder it gets, which means that the lower the air temperature, the fewer species have evolved to survive it. this factor, in conjunction with the decline in air temperature with increasing elevation, explains the distribution of species diversity in mountain ecosystems: you find fewer species high up a mountain than at the mountain’s base because ______.
which choice most logically completes the text?
choose 1 answer:
a there are relatively few environments hospitable to species that are adapted to live in low air temperatures.
b there are relatively few species with the adaptations necessary to tolerate the temperatures at high elevations.
c adaptations that allow plants and animals to survive in rocky environments are metabolically costly.
d some mountain environments are at elevations so high that no plants or animals can survive them.

Explanation:

The text explains that adapting to cold temperatures has high metabolic costs, and the colder it is, the fewer species can survive. At high mountain elevations, temperatures are colder. Option B states there are relatively few species with adaptations to tolerate high - elevation temperatures, which logically connects to the idea that fewer species can survive the cold at high elevations, thus explaining the lower species diversity there. Option A focuses on environments for cold - adapted species, not why fewer species are at high elevations. Option C talks about rocky environments, which is not relevant. Option D is about some environments being too harsh, but the text is about the general trend of fewer species with increasing elevation due to temperature - related adaptations, not about uninhabitable environments.

Answer:

B. there are relatively few species with the adaptations necessary to tolerate the temperatures at high elevations.