AP Biology : Understanding Ecosystems

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #31 : Understanding Ecosystems

Which of the following best describes when secondary succession occurs?

Possible Answers:

An environment lacking plant and animal life

All of these

A currently inhabited environment

A previously inhabited environment

Correct answer:

A previously inhabited environment

Explanation:

Secondary succession can be described as the colonization of a habitat that once supported plant and animal life but was abandoned due to ecological disturbance. Types of ecological disturbances such as hurricanes and floods can empty a habitat.

Example Question #31 : Ecology

How does human initiated deforestation impact ecosystems?

Possible Answers:

Increase in biodiversity

Decrease in soil erosion

None of these

Decrease in greenhouse gas emissions

Correct answer:

None of these

Explanation:

Deforestation can be defined as the removal of forests by humans. Deforestation has many negative environmental impacts including soil erosion, a decline in biodiversity, and an increase in greenhouse gas emissions.

Example Question #32 : Understanding Ecosystems

Which of the following human activities directly impacts marine environments?

Possible Answers:

Burning of fossil fuels

Overfishing

Deforestation

Industrialization

Correct answer:

Overfishing

Explanation:

Human activities can have negative impacts on the proper functioning of ecosystems and environments. One human activity that has a direct impact on marine environments is overfishing, which may critically change the delicate balance of the ecosystem.

Example Question #31 : Ecology

Which of the following terms is used to describe the speed at which equilibrium is re-established after a disturbance?

Possible Answers:

Succession

Resistance

Resilience

Biodiversity

Correct answer:

Resilience

Explanation:

“Resilience” is the term used to describe the speed at which an ecosystem can re-establish equilibrium after a disturbance.

Example Question #31 : Ecology

Which of the following is true regarding tropical rainforest biomes?

Possible Answers:

Soil is nutrient-rich

There are three seasons: rainy, dry, and winter

They have the greatest biodiversity

There is little rainfall

Correct answer:

They have the greatest biodiversity

Explanation:

Tropical rainforest biomes have the greatest biodiversity of all biomes. They have only two seasons (rainy and dry) and the soil in these environments is generally nutrient-poor. Tropical rainforests also have a multi-layered canopy that allows little light to penetrate to the ground.

Example Question #32 : Understanding Ecosystems

Which of the following is not true regarding temperate forest biomes?

Possible Answers:

Soil is nutrient-rich

There is little ground vegetation

There are temperate forests in eastern North America

They have a distinct winter season

Correct answer:

There is little ground vegetation

Explanation:

Temperature forest biomes can be found in eastern North America and western and central Europe. Temperate forests have a distinguishable winter season. The canopy present in these forests allows light penetration and ground vegetal growth, which makes the soil nutrient-rich.

Example Question #33 : Understanding Ecosystems

Which of the following best explains how marine biomes are distinct from freshwater biomes?

Possible Answers:

Freshwater biomes have high salt concentration while marine biomes have low salt concentration

Marine biomes have high salt concentration while freshwater biomes have low salt concentration

Freshwater biomes are greater oxygen sinks than marine biomes

Freshwater biomes contain algae that supplies most of the Earth’s oxygen, while marine biomes do not

Correct answer:

Marine biomes have high salt concentration while freshwater biomes have low salt concentration

Explanation:

Marine biomes are aquatic ecosystems that possess a high concentration of salts. Examples of marine biomes include oceans, coral reefs, and estuaries. Marine biomes contain large quantities of algae that supply most of the Earth’s oxygen content.

Example Question #34 : Understanding Ecosystems

Which of the following types of aquatic ecosystems are exemplary of freshwater biomes?

Possible Answers:

All of these

Ponds and lakes

Streams and rivers

Wetlands

Correct answer:

All of these

Explanation:

Freshwater biomes are a type of aquatic ecosystem characterized by a low salt concentration and are home to animals specifically adapted to survive in these conditions. Types of freshwater biomes include ponds and lakes, wetlands, and many streams and rivers.

Example Question #31 : Ecology

Which of the following best characterize desert biomes?

Possible Answers:

Low rainfall

Low rainfall and animal adaptations to a water-poor environment

Animals are adapted to a water-poor environment

Neither low rainfall nor animal adaptations to a water-poor environment

Correct answer:

Low rainfall and animal adaptations to a water-poor environment

Explanation:

Low rainfalls as well as the organisms that are specifically adapted to inhabit these conditions characterize desert biomes. Desert biomes can be further characterized based on seasons.

Example Question #32 : Ecology

Which of the following is not a true characteristic of tundra?

Possible Answers:

Short growing seasons

Lack of dead organic material

Low biodiversity

Cold climate

Correct answer:

Lack of dead organic material

Explanation:

The tundra is a type of biome that has an extremely cold climate. Other characteristics of the tundra include a short growth season, low biodiversity, and nutrients found only in the form of dead organic tissue. The tundra is also characterized by the presence of a permafrost layer—a layer of frozen soil.

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