Exam 3: The Biosphere

Which biome contains only 11% of Earth's terrestrial vegetation cover, but is home to about half of Earth's species?

Refer to the map. Part B on the map shows the alteration of terrestrial biomes by human activities (i.e., the "human footprint"), with green representing the least human impact and purple-red representing the most. Rank the following countries with respect to how much human activity has altered their native biomes (from most to least impact): India, United States, and Russia.

Deciduous trees would most likely be found in which of these forest types?

Refer to the figure. -Suppose that growing a plant requires an average of 10 mm of precipitation plus 1 mm of precipitation for every degree the average monthly temperature exceeds freezing. The plant also requires an average monthly temperature above freezing. Based on the climate diagram, and assuming that the temperature conforms to the long-term climatic average, during how many months of the year should the plant be able to grow?

Refer to the figure. -The figure shows how biomes vary with temperature and precipitation. If the average temperature on Earth increased, what effect would this have on the distribution of boreal forests in the Northern Hemisphere?

The primary difference between tundra and boreal forest is that

One characteristic of freshwater ecosystems, as compared with terrestrial ecosystems, is that freshwater ecosystems

Which of the following results, if found to be true, would provide evidence against the overkill hypothesis as the cause of extinction of North American megafauna?

Which factor most likely prevented the grasslands at the eastern edge of the Great Plains from becoming forest?

Animals in the ocean's photic zone are likely to be more abundant and more diverse because of high levels of which factor present at this level?

Livestock grazing in deserts and desert margins is likely to result in all of these changes to the environment except

If climate change causes a boreal forest to be a little warmer and a little wetter, it will most likely become

Consider both the particle size on the stream bottom and the number of rooted and floating macrophytes in a higher-order stream, such as the Mississippi River, compared to a small first-order source stream of the Mississippi. The river would have

Certain fly larvae living in rivers consume detritus and can move most freely through fine particles. These fly larvae are most likely to be found in which part of the river?

Which condition is more likely to occur in tundra than in tropical alpine locales?

The coldest part of a large lake is usually in which zone?

Seagrass beds form underwater meadows that are often closely associated with coral reefs. What is one likely reason for this association?

Two sites of a biome both occur at a latitude of about 30°N. One site is in Mexico, the other in Ethiopia. Many of the plants at these two sites are succulents, with water-storing stems and many spines. The climate in this biome is most likely

A certain biome is characterized by sedges, forbs, grasses, low-growing shrubs, lichens, and mosses. Its growing season is short, but summer days are very long. Although precipitation is low, the soil is often wet. Alternate freezing and thawing of soil results in a pattern of polygons and pingos on the soil surface. This biome is most likely

Refer to the figure. Based on the climate diagram, when would trees in this biome most likely drop their leaves?