#Question id: 9168
#Unit 9. Diversity of Life Forms
Which of the following statements best describes the interaction between fire and ecosystems?
#Question id: 9169
#Unit 9. Diversity of Life Forms
In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce often "lean over" (that is, they are displaced from their normal vertical alignment). What is the most likely explanation for the unusual growth of these forests in this marginal habitat?
#Question id: 9170
#Unit 9. Diversity of Life Forms
Which of the following is an important feature of most terrestrial biomes?
#Question id: 9171
#Unit 9. Diversity of Life Forms
Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?
#Question id: 9172
#Unit 9. Diversity of Life Forms
Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of ________.
#Question id: 9173
#Unit 9. Diversity of Life Forms
Use the following figure to answer the question below
In the figure, which number would designate the arctic tundra biome?