Question 1

In which of the following terrestrial biome pairs are both biomes dependent upon periodic burning?

Accepted Answer

Both chaparral and savanna biomes are dependent upon periodic burning. In chaparral, fires are essential for maintaining the ecosystem, as many plants require fire to germinate and new growth occurs after a fire. Similarly, savannas have a natural fire regime, which prevents woody plants from encroaching on grasslands and promotes growth of new grasses.

Question 2

Which of the following levels of ecological organization is arranged in the correct sequence from most to least inclusive?

Accepted Answer

The correct sequence from most to least inclusive is ecosystem (includes all living and nonliving components of an environment), community (all populations of different species in the same area), population (all individuals of the same species in a given area), and individual (one organism).

Question 3

Deserts typically occur in a band around 30 degrees north and 30 degrees south latitude because

Accepted Answer

Descending air masses originating from the tropical areas tend to be dry, leading to arid conditions and the formation of deserts. This is why deserts are typically found in a band around 30 degrees north and 30 degrees south latitude.

Question 4

A cosmic catastrophic event occurred that caused the tilt of the Earth's axis relative to its plane of orbit to increase from 23.5 degrees to 90 degrees.The most obvious effect of this change would be

Accepted Answer

A tilt of 90 degrees would cause the Earth to be perpendicular to its plane of orbit, resulting in sunlight being distributed evenly across the planet throughout the year. This would eliminate seasonal variations, as each hemisphere would receive the same amount of sunlight all year round.

Question 5

Which of the following choices causes all of the others in creating global terrestrial climates?

Accepted Answer

Differential heating of Earth's surface drives the circulation of air and water and ultimately determines global terrestrial climates. Ocean currents (B) are influenced by differential heating, wind patterns (C) are a result of differential heating and evaporation (D) is influenced by temperature and wind patterns.

Question 6

Which of the following statements best describes the effect of climate on biome distribution?

Accepted Answer

Both average climate and the pattern of climatic variation are important in determining the nature of an area biome. This means that it is not just the average annual temperature and precipitation that determines the biome distribution, but also the seasonal variation of climate, such as the amount of rainfall, temperature fluctuations, or severity of droughts or floods. Therefore, the nature of a biome is a result of complex and interacting factors, including climate, geology, soil, vegetation, and human activities, making it difficult to predict or explain biome distribution based on a single factor alone.

Question 7

The tilt of the Earth's axis relative to its plane of orbit is 23.5 degrees.Which of the following events might you predict to occur if the angle of tilt increased to 33 1/2 degrees?

Accepted Answer

An increase in the angle of tilt would lead to more direct sunlight hitting the Earth's surface in the Northern Hemisphere during summer months, leading to warmer temperatures. This would especially be noticeable in the United States, which is located in the Northern Hemisphere. The other options are not necessarily true or likely to occur with an increase in the tilt of the Earth's axis.

Question 8

In mountainous areas of western North America,which type of plant life would you expect to find on a southern-slope of a mountain?

Accepted Answer

Southern slopes in mountainous areas of western North America receive more direct sunlight, leading to drier conditions. Drought-tolerant plants are better adapted to these conditions.

Question 9

Palm trees and subtropical plants are commonplace in Land's End,England,whose latitude is the equivalent of Labrador in coastal Canada,where the local flora is subarctic.Which of the following contributes the most to the differences between these two biomes?

Accepted Answer

The primary factor contributing to the differences between the biomes of Land's End, England, and Labrador, Canada, despite their similar latitudes, is the direction of ocean currents. The warm North Atlantic Drift, a continuation of the Gulf Stream, moderates the climate of Land's End, allowing for the growth of palm trees and subtropical plants. In contrast, Labrador does not benefit from such warm currents, resulting in a subarctic biome.

Question 10

Generalized global air circulation and precipitation patterns are dependent on the intensity of solar radiation near the equator.Which of the following correctly states an event that contributes to the creation of these global patterns?

Accepted Answer

As the sun's rays are most intense near the equator, they heat the air and cause rising air masses to expand and cool in the tropical regions. This creates low-pressure zones that lead to the formation of zones of circulating air that drive the global air circulation and precipitation patterns. Therefore, choice B is the correct answer, as it describes the event that contributes to the creation of these patterns. Choices A, C, and D do not describe events that contribute to the creation of global air circulation and precipitation patterns.

Question 11

A particular mountain range is subjected to prevailing winds.Which of the following contributes the most to a drier climate on the leeward side of the mountain range?

Accepted Answer

As air rises up the windward side of the mountain range, it expands and cools, causing moisture to condense and fall as rain or snow. This process, known as orographic lift, results in a drier climate on the leeward side of the mountain range.

Question 12

With respect to the sun,Earth normally rotates once in a 24-hour period.What would be the effect on climate in the temperate latitudes if the rotation increased to 48-hours?

Accepted Answer

With a 48-hour rotation period, each day and night would be twice as long as they are now, leading to more extreme temperatures: hotter days and colder nights. This is because the surface would have more time to heat up under the sun during the day and more time to cool down during the extended nights.

Question 13

Air masses formed over the Pacific Ocean eventually encounter extensive north-south mountain ranges as they move from west to east.Which statement best describes a component of an outcome of this encounter between a mountain range and an air mass?

Accepted Answer

As the air mass encounters the mountain range, it is forced to rise up the windward side. As it rises, it cools and releases its moisture as precipitation. This results in a wet climate on the windward side of the range and a dry climate on the leeward side. This process is known as orographic lifting.

Question 14

Fire suppression by humans

Accepted Answer

Fire suppression by humans can lead to changes in the species composition within biological communities. For example, in areas where fires were previously common, tree species may become more dominant if fires are suppressed, leading to a decrease in plant species diversity. Similarly, in areas where fires are important for maintaining grassland or savanna ecosystems, fire suppression can result in a shift towards more woody vegetation and a decrease in plant diversity. However, it is important to note that the effects of fire suppression can be complex and may vary depending on the specific biome and local ecological conditions.

Question 15

The main reason that polar regions are cooler than the equator is that

Accepted Answer

Sunlight strikes the poles at a lower angle, which means the same amount of energy is spread over a larger area, resulting in cooler temperatures. The other options do not fully explain why the polar regions are cooler than the equator.

Question 16

What is the limiting factor for the growth of trees in the tundra?

Accepted Answer

The primary limiting factor for tree growth in the tundra is permafrost, which prevents tree roots from penetrating deep into the soil for nutrients and water, and also keeps the soil temperature very cold, limiting growth.

Question 17

Trees are rare in the savanna biome because of

Accepted Answer

Savannas have a long dry season and a short wet season, which makes the grasses dry and flammable. Frequent fires are therefore an integral part of the ecosystem, reducing competition from woody plants and keeping the savanna open. As a result, few trees grow in the savanna.

Question 18

Coral reefs can be found on the southeast coast of the United States but not at similar latitudes on the southwest coast.Differences in which of the following most likely account for this?

Accepted Answer

Ocean currents play a significant role in the distribution of coral reefs. The southeast coast of the United States is influenced by the Gulf Stream, a warm ocean current that brings tropical water towards the coast. The southwest coast, on the other hand, is influenced by the California Current, a cold current that brings nutrient-rich water towards the coast. Coral reefs thrive in warm water with low nutrient levels, making the conditions on the southeast coast more favorable for their growth compared to the southwest coast.

Question 19

Areas where terrestrial biomes grade into neighboring biomes way be wide or narrow.Which of the following terms best describes this intergradation?

Accepted Answer

An ecotone refers to an area where two or more different ecosystems (or biomes) meet and intergrade. This zone of transition may be wide or narrow, and the species in the area may be a mixture of those from adjacent biomes.

Question 20

The growing season would generally be shortest in which of the following biomes?

Accepted Answer

The growing season in a Northern pine forest would generally be the shortest among the options given due to its colder climate and shorter summers.

Quiz 40: Population Ecology and the Distribution of Organisms