AP Environmental Science : Ecological Change

Study concepts, example questions & explanations for AP Environmental Science

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Example Questions

Example Question #72 : Ecosystems And Biology

Which type of erosion is caused by steady, fast flow of running water?

Possible Answers:

Splash erosion

Gully erosion

Sheet erosion

Rill erosion

Correct answer:

Gully erosion

Explanation:

All of these are caused by water in some way, however, gully erosion is due to steady and fast-flowing streams; the Grand Canyon is an excellent example of the effect of gully erosion. Splash erosion is the first step in erosion from water, and involves the breakage of soil via the impact between soil and a raindrop. It is often a precursor for other types of erosion since it loosens soil. Sheet erosion involves evenly removing a certain number of layers of material due to regular water patterns. Rill erosion is a result of small, well-defined paths of water known as rills, that flow downhill after rainfall. 

Example Question #73 : Ecosystems And Biology

Climatologists work to understand what factors affect climate throughout geological time. Scientists have proposed many theories to explain complex climatic events. Which of the following theories explains how shift’s in Earth’s orbit every 100,000 years can trigger ice ages?

Possible Answers:

La Nina cycles

El Nino cycles

Hadley cells

Milankovitch cycles

Correct answer:

Milankovitch cycles

Explanation:

The correct response is Milankovitch cycles. This theory describes how the orbit, tilt, and axis of the Earth operate on a 100,000 year cycle that cause the Earth to be further from the sun. As the Earth gets farther from the sun, it can trigger an ice age. The theory is aptly named after the man who discovered it. The El Nino and La Nina events occur on a much shorter time scale and have nothing to do with ice ages. 

Example Question #3 : Change Due To Natural Events

In the past 500 million years, there have been __________ mass extinctions.

Possible Answers:

10

5

2

50

Correct answer:

5

Explanation:

Today, 99.9% of all species that have ever existed on Earth are extinct. We are currently in the middle of the 6th mass extinction. The dinosaurs went extinct during the 5th, the Cretaceous, about 65 million years ago.

Example Question #2 : Change Due To Natural Events

The Wallace Line is generally cited as evidence of which of the following?

Possible Answers:

Plate tectonics

Speciation

Change in sea levels

Natural Selection

Asteroid impact

Correct answer:

Change in sea levels

Explanation:

The Wallace Line, named for Alfred Russel Wallace, is a boundary that separates Asia and Australia. Wallace noticed that the some of the islands in this region contained species common to Australia and some contained species common to Asia, none of which would have crossed the open water in between the continents. Wallace correctly reasoned that this meant that sea levels were once much lower, an artifact of the last glacial maximum.

Example Question #1 : Evolution

The streamlined shape found in the body plans of both sharks and dolphins is an example of:

Possible Answers:

none of these

convergent evolution

sympatry

divergent evolution

coevolution

Correct answer:

convergent evolution

Explanation:

Sharks and dolphins are not closely related and evolved their streamlined shapes separately from one another. This is an example of convergent evolution, in which two species that are not closely related evolve similar characteristics. Divergent evolution is the opposite.

Example Question #75 : Ecosystems And Biology

What type of organisms were the first to develop?

Possible Answers:

Eukaryotes

Primates

Fungi

Prokaryotes

Plants

Correct answer:

Prokaryotes

Explanation:

Prokaryotes are simple, single-celled organisms which lack membrane bound nuclei. They developed before any of the other listed answer choices, as all of the other listed answer choices are multi-celled organisms that developed from prokaryotes.

Example Question #3 : Evolution

Which of the following terms is defined as any change in the proportions of different genotypes in a population from one generation to the next?

Possible Answers:

Adaptation

Variability

Gene flow

Evolution

Differential reproduction

Correct answer:

Evolution

Explanation:

Evolution is a process of orderly and gradual change or development. The theory that all living species have developed as a result of changes in their genetic material over time. Evolution is a change in the proportions of different genotypes in a population from one generation to the next. The characteristic of an organism that helps it survive and reproduce in a particular environment is adaptation. Variability is the range of alterations present in a genome, such as the number of diverse alleles of a specific gene. The differences in reproductive output among individuals of a population, normally as a result of genetic differences is differential reporduction. Gene flow is the movement of alleles from one population to another owing to the migration of individual organisms. 

Example Question #8 : Ecological Change

Which of the following does not represent a process leading to evolution?

Possible Answers:

Reproductive isolation

Geographic isolation

Speciation

Coevolution

All of these

Correct answer:

Coevolution

Explanation:

Coevolution occurs when one species evolves at the same time as another related species. Often one of these species is a prey-animal that adapts or develops traits that increase survival and reproductive rates. The predator that hunts the prey is required to adapt, increasing favorable traits that allow them, once again, to be able to hunt the prey. Coevolution is a type of evolution, but is not a cause of evolution.

Speciation is a general term referring to evolutionary processes leading to the creation of a new species. This occurs when a parent species is divided into at least two groups that are isolated from each other. These isolated groups adapt and mutate separately until they are no longer compatible for breeding.

Evolution caused by geographic isolation takes place when a species is separated into multiple groups due to a physical barrier of some kind (like a rock fall blocking a previously open canyon).

Evolution due to reproductive isolation occurs when members of two species that were previously able to produce viable offspring cannot due to changes in physical characteristics or behaviors. These species can procreate, but their offspring are not viable (able to reproduce).

Example Question #1 : Evolution

Which of the following terms describes the evolution that species have in response to one another and was authored by Charles Mode in 1958?  This term was used to describe his fascination with the evolutionary responses that crops and pests have to each other. 

Possible Answers:

Convergence

Coevolution

Divergence 

Sympatric 

Correct answer:

Coevolution

Explanation:

The correct answer is coevolution. It is defined as the continual evolution that interacting species have in response to each other.

Example Question #2 : Evolution

Which statement is true about genetic drift?

Possible Answers:

Genetic drift occurs only in eukaryotes.

Genetic drift is completely random.

Genetic drift is a process created by humankind. 

Genetic drift occurs only in producers

Genetic drift occurs only in animals.

Correct answer:

Genetic drift is completely random.

Explanation:

The correct response is: genetic drift is completely random. It is a natural process that occurs at random and has profound impacts on species. Thus, genetic drift was not created by humans - it's a natural process. Genetic drift occurs in life forms, from the prokaryotes to the eukaryotes. And genetic drift occurs in all living organisms: plants, animals, bacteria, and fungi.

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