2.9 MC Answers and Review

⛔STOP!⛔ Before you look at the answers make sure you gave this practice quiz a try so you can assess your understanding of the concepts covered in unit 2. Click here for the practice questions: AP Environmental Science Unit 2 Multiple Choice Questions.

Facts about the test: The AP Environmental Science exam has 80 multiple choice questions and you will be given 1 hour 30 minutes to complete the section. That means it should take you around 17 minutes to complete 15 questions.

1. Which of the following is a method used to measure species diversity?

A. Species Wealth

B. Species Diversity

D. Species Concentration

Answer: The measurement of species richness indicates the number of different species that are found in a given area.

📄 Study AP Environmental Science, Unit 2.1 Introduction to Biodiversity

2. The amount of any one given species relative to others in a given area is the measurement of

B. Species Richness

C. Biodiversity

D. Ecological weight

Answer: Species evenness is a measurement of the number of one species compared to others in its area. For example, a field with one horse and 20 cows would have a lower species evenness than a field with 10 cows and 11 horses.

📄 Study AP Environmental Science, Unit 2.1 Introduction to Biodiversity

3. Although we do not know exactly how many species are currently alive on Earth, the current estimate is close to

A. 1 billion

B. 100 million

D. 1 million

Answer: Scientists use models based on estimated species diversity and unexplored or underexplored areas.

📄 Study AP Environmental Science, Unit Overview

4. Ecologists use which of the following measurements to calculate biodiversity by looking at the number of species present and their abundance.

A. Species Richness

B. Species Evenness

C. Hardy-Weinberg Index

Answer: Shannon's index accounts for both the total abundance and the evenness of the species that are present in an ecosystem.

📄 Study AP Environmental Science, Unit Overview

5. If a normal-looking zebra has an offspring that is born completely white and has no stripes this is most likely due to

A. Natural variation

C. Adaptation

D. Natural selection

Answer: The offspring would have had a genetic mutation that caused a different phenotypic outcome. This outcome may be advantageous or a disadvantage to its survival.

📄 Study AP Environmental Science, Unit 2.6 Adaptations

6. Which of the following is not a process that leads to the evolution of a new species

A. Artificial Selection

C. Natural Selection

D. Genetic Drift

Answer: Although it is possible for a genetic mutation to occur and a new species to develop from random breeding, it is much less likely to develop another species than the other processes.

📄 Study AP Environmental Science, Unit 2.6 Adaptations

7. Breeding cattle to make them grow larger, faster is an example of

B. Genetic Drift

C. Founder Effect

D. Mutation

Answer: Artificial selection is when humans determine the genetics that will be kept in the subsequent generations of a species. This is a nonrandom selection of phenotypes.

📄 Study AP Environmental Science, Unit 2.6 Adaptations

8. Often species that live on islands are ____ due to the limited types of resources.

B. Generalist

C. Autotroph

D. Heterotroph

Answer: Species that are isolated to islands are often specialists because there is not a wide variety of resources like food types for them to access.

📄 Study AP Environmental Science, Unit 2.3 Island Biogeography

9. Which of the following is known for being a widespread invasive species?

A. Bottlenose Dolphin

B. Domestic Cattle

C. Ravens

Answer: Cane toads were introduced into sugarcane fields as a way to control beetle populations. They were able to take over many islands and Australia due to their ability to eat a variety of foods and resist predation.

📄 Study AP Environmental Science, Unit 2.3 Island Biogeography

10. Ecological Tolerance acts on

B. Only Individuals

C. Only Species

D. Neither Individuals or Species

Answer: Ecological tolerance is the range of conditions that an organism can endure before it would die, this concept would impact individuals and a species as a group. For example, if a drought hit, the weakest individuals would die first, and if it continued for an extreme amount of time the weakest species would die out completely.

📄 Study AP Environmental Science, Unit 2.5 Natural Disruptions to Ecosystems

11. Changes in sea level are most directly related to

A. the total amount of water in lakes and streams.

C. the total amount of water used in irrigation.

D. the total amount of water all species consume.

Answer: Glaciers store huge quantities of freshwater. Natural and man-made climate change causes glaciers to melt, letting water enter the oceans and increasing sea levels.

📄 Study AP Environmental Science, Unit 2.5 Natural Disruptions to Ecosystems

12. Scientists observed that kelp forests off the coast of California disappeared after sea otters were hunted to extinction. When they were introduced to their natural habitats again they noticed that the otters ate urchins and kept their numbers low so that the kelp could grow back. In this case, sea otters are an example of a

A. Primary Consumer

C. Invasive Species

D. Detritivore

Answer: Keystone species are vital to the health of the overall ecosystem. When they are removed there is often a collapse of the entire ecosystem. In this example, the loss of sea otters resulted in the loss of the entire kelp forest and the hundreds of animals that lived there. Other examples are wolves, sharks, and beavers.

📄 Study AP Environmental Science, Unit Overview

13. Which of the following is not an example of an ecosystem service?

A. Supporting

B. Regulating

C. Provisioning

Answer: The four ecosystem services are provisioning, regulating, supporting, and cultural.

📄 Study AP Environmental Science, Unit 2.2 Ecosystem Services

14. An abandoned city parking lot becoming overgrown with plants is an example of

B. Secondary succession

C. Adaptation

D. Perseverance

Answer: Primary succession is when plants begin to establish a community where there is no base of soil. This naturally occurs where there has been a geologic disruption and there is only exposed rock at the surface.

📄 Study AP Environmental Science, Unit 2.7 Ecological Succession

15. Secondary succession is characterized by the

B. exposed rock.

C. existence of trees.

D. available water.

Answer: Secondary succession occurs when a new community of organisms moves into an area that has an established soil base, for example after a fire.

📄 Study AP Environmental Science, Unit 2.7 Ecological Succession

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