AP Environmental Science : Biodiversity

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #1 : Biodiversity

Which of the following is the best example of critical habitat?

Possible Answers:

Alaska Native American tribes sustain their communities with wild salmon, and the salmon rely on specific river habitats to repopulate.

Wetland and riparian ecosystems are vital foraging and breeding grounds for the endangered whooping crane.

Ponds are preferred foraging grounds for bull frogs, and if they were developed on, the frogs would need to forage in nearby rivers, which have less available food.

Nomads in the Sahara have long relied on scattered oases as a source of food and water for their camel herds.

Many species of hawk rely on trees to spot prey and would be less successful at hunting if there was logging.

Correct answer:

Wetland and riparian ecosystems are vital foraging and breeding grounds for the endangered whooping crane.

Explanation:

Critical habitat is defined as vital for sustaining endangered or threatened populations. The whooping crane is endangered and requires wetland ecosystems to sustain a population, while the other examples are situations where alternative (albeit less successful) habitat was available or the population was neither threatened nor endangered.

Example Question #2 : Biodiversity

What is the approximate proportion of amphibian species worldwide that are at risk of extinction?

Possible Answers:

1 in 5

1 in 2

1 in 3

1 in 6

1 in 8

Correct answer:

1 in 3

Explanation:

Amphibians are one of the most susceptible groups of species to mass extinction, with one in three currently at risk of extinction.

Example Question #2 : Biodiversity

How does the 6th mass extinction significantly differ from the other 5 mass extinctions that have occurred throughout the history of Earth?

Possible Answers:

Human activities (overhunting, habitat destruction, greenhouse gases, etc.) are the primary contributing factor in the 6th mass extinction, which was not the case for the other events. 

The 6th mass extinction event is projected to not be as severe in species loss as previous extinction events. 

The 6th mass extinction is the only extinction event to have occured when dinosaurs were not inhabiting earth. 

The other mass extinction events were caused by meteors striking earth, while the 6th mass extinction is a result of radical climate change. 

The 6th mass extinction was a result of a meteor hitting earth, unlike previous extinction events, which were largely the result of climate change. 

Correct answer:

Human activities (overhunting, habitat destruction, greenhouse gases, etc.) are the primary contributing factor in the 6th mass extinction, which was not the case for the other events. 

Explanation:

Previous extinction events can be attributed to pathology, climate change and other natural factors. The current 6th mass extinction event is largely attributed to human activities and the resulting climate change. 

Example Question #31 : Global Effects And Dynamics

In the 1960s, Robert MacArthur and E.O. Wilson came up with one of the most prominent theories in the field of ecology—Island Biogeography Theory. This theory describes the balancing of which of the following two processes?

Possible Answers:

Predation and population growth 

Dispersal and reproduction

Immigration and emigration

Immigration and extinction

Correct answer:

Immigration and extinction

Explanation:

Island Biogeography Theory is related to the balancing of immigration and extinction. In short, the number of species that occurs on an island should be directly related to the rate of extinction and the rate of immigration. If the rate of immigration is higher than the rate of extinction, then the number of species will be high. If the rate of extinction is higher than the rate of immigration, then the number of species will be low. 

Example Question #2 : Biodiversity

The ecologist Joseph Connell studied tropical rain forests and noticed that they contain high levels of biodiversity compared to temperate zones. He noted that earthquakes and storms are important forces that continually open canopies and create new habitat for species colonization. Which of the following hypotheses best describes this phenomenon?

Possible Answers:

Intermediate Disturbance Hypothesis

Biodiversity Satiation Theory

Equilibrium Theory

Janzen-Connell Hypothesis

Correct answer:

Intermediate Disturbance Hypothesis

Explanation:

The Intermediate Disturbance Hypothesis describes how habitats experiencing moderate levels of disturbance can support the most species. This occurs because disturbance initiates the turnover of dominant species, which allows new species to emerge. For example, a tree falling in the forest could be an example of a disturbance. Trees falls open up the canopy and allow sunlight to reach the floor of the forest and creates an open space for species to colonize. 

Example Question #3 : Biodiversity

Beta diversity refers to the difference in species across habitats. If an area of particular interest has 8 different habitats and an average of 3.2 species occupying each habitat, then what would the beta diversity be?

Possible Answers:

Correct answer:

Explanation:

Beta diversity is calculated by taking the total number of habitats divided by the number of species in each habitat of a given environment. 

Total number of habitats:

Number of species in each habitat: 

Solve:

Example Question #2 : Biodiversity

Diversity can be calculated at various scales. Which type of diversity refers to the total number of species in a geographic region that spans multiple habitats?

Possible Answers:

Alpha diversity

Delta diversity

Beta diversity

Gamma diversity

Correct answer:

Gamma diversity

Explanation:

Gamma diversity refers to the total number of species within a region. This can also be referred to as regional diversity. Gamma diversity is useful in order to investigate biodiversity from a broad scale or at the landscape level.

Example Question #2 : Biodiversity

Biological diversity is the variation between organisms in a ecosystem; both plant and animal.

What three aspects are taken into account when measuring biological diversity?

Possible Answers:

Location and number of organisms

Location and genetics of organisms

Number and variety of species

Number, variety, and variability of organisms

Number and variety of ecosystems

Correct answer:

Number, variety, and variability of organisms

Explanation:

Biological diversity is concerned with not only the number, variety and variability of species within ecosystems but the number of ecosystems on the Earth and genetic diversity within species. 

Example Question #2 : Biodiversity

Imagine that there is a museum that contains every species that has ever lived on planet Earth. Of all the species that have ever existed on Earth, what percentage of those are still alive today?

Possible Answers:

25%

1%

50%

10%

Correct answer:

1%

Explanation:

The correct response is 1%. The majority of species that have ever lived on Earth are extinct. Mass extinctions have occurred throughout geological history due to large disturbances such as meteor crashes and ice ages. Life is fragile and disturbances can cause millions of species to go extinct rather quickly - such as most recent mass extinction when the dinosaurs disappeared. Thus, the species still alive today represent a tiny portion of the variety of life that has existed throughout the geological history of Earth.

Example Question #4 : Biodiversity

Riparian zones are important because __________.

Possible Answers:

they are centers of biodiversity, especially in arid ecosystems

they are one of the easiest ecosystems to manage

they are very quickly eroded

they cover vast areas of terrain

Correct answer:

they are centers of biodiversity, especially in arid ecosystems

Explanation:

Riparian zones prevent erosion and are incredibly high in biodiversity. Riparian areas are thin and ribbon-like, accompanying streams and rivers, but often long and dense.

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