Question 1

What is the most common reason species become endangered?

Accepted Answer

A)   Pollution
B)   Overharvesting
C)   Habitat destruction
D)   Displaced by invasive species
E)   Killed by predators

Question 2

The productivity hypothesis says that there is higher species diversity at the equator than toward the poles because the climate is perfect to grow plants. Besides just the volume of food, why might this allow for there to be more species?

Accepted Answer

A)   There are more places to hide.
B)   There is more variety of plants, so there can be species specializing in eating just one type, allowing more species to "fit" in the habitat.
C)   Species can be more generalists than specialists, and generalists tend to not go extinct as easily.
D)   There are just more plant species toward the equator and that alone accounts for the higher species richness.
E)   Rainforests are among the most productive of ecosystems and they tend to be equatorial.

Question 3

Deserts in North Africa are very similar to deserts in North America, and so pretty much the same group of species lives in each place.

Accepted Answer

A) True 
 B)False

Question 4

Worldwide, diversity of species tends to decrease as you move away from the equator. What do ecologists call this phenomenon?

Accepted Answer

The latitu...

Question 5

It appears that humans are a powerful force for extinction. What is this hypothesis called?

Accepted Answer

The blitzk...

Question 6

Geographic relief in a region allows for higher biodiversity. What is this?

Accepted Answer

A)   A relatively stable climate
B)   A relative warm, but not too hot, climate
C)   Variation in species with microclimates
D)   High altitude, where biodiversity is naturally higher.
E)   Variation in altitude, like you would find in a mountainous region

Question 7

How does the theory of island biogeography apply to habitats not on islands?

Accepted Answer

A)   It doesn't. It only works on islands.
B)   On land, the relationship is reversed. Smaller areas of land tend to have relatively more species.
C)   Small isolated areas of habitat on land, surrounded by unsuitable habitat, are like "islands" so bigger areas have more species.
D)   It's similar but on land, species on "islands" of habitat are much less likely to go extinct because it's easier to migrate.
E)   No one has tried to apply it to land, but it seems like it would work the same way.

Question 8

All species go extinct. About how long is the average lifespan of a species?

Accepted Answer

A)   One extinction per million species per year
B)   1 million years
C)   One geologic period, like the Cretaceous
D)   100,000 years
E)   Between 1 and 5 million years

Question 9

The country of Honduras is about the same size as the state of Virginia. Where would you expect to find higher species diversity? Why?

Accepted Answer

A)   Honduras, because Virginia probably has more people.
B)   Honduras, because it's closer to the equator.
C)   There's no way to estimate this. You would have to survey.
D)   Virginia, because the United States has the Endangered Species Act to protect species
E)   Virginia, because the climate is more variable over a year.

Question 10

Why are species living on islands more likely to go extinct than those living on the mainland?

Accepted Answer

A)   Islands are more fragile habitats.
B)   Island populations are often very small to start with, and then resources are limited.
C)   People like to live on islands, so they often take over essential habitat.
D)   Predators can easily take over on an island.
E)   New individuals rarely migrate to islands.

Question 11

To have high species diversity in an ecosystem, you need which of the following combinations?

Accepted Answer

A)   High species richness, and uneven but high species abundance
B)   High species richness and even species abundance
C)   High species evenness and richness, but not necessarily high abundance
D)   High but uneven abundance and low species richness
E)   High and even species abundance and low species richness

Question 12

What regulating services do intact old-growth forests provide?

Accepted Answer

Retain and...

Question 13

The controversy between loggers and conservationists in the Pacific Northwest was framed as a fight over an owl, but what was it really about?

Accepted Answer

A)   Whether an old-growth forest is really valuable
B)   Most fights over habitat in the Pacific Northwest actually come down to salmon.
C)   Short-term versus long-term benefits of an old-growth forest
D)   Climate change
E)   The effectiveness of the Endangered Species Act

Question 14

The model of island biogeography is a mathematical model. How do we know it actually holds true in the "real" world?

Accepted Answer

A)   Mathematical models are always accurate
B)   Scientists collect data from real ecosystems to test it.
C)   The modelers tested it extensively in the field before they published it.
D)   The Simberloffs tested it in mangroves in Florida.
E)   We don't actually know, but it makes sense.

Question 15

Overharvesting of species we consume is the single biggest cause of species becoming endangered. True or false?

Accepted Answer

A)   True. As human population grows we need more and more to eat, so this is generally the reason species become endangered.
B)   True. Food species are increasingly going extinct these days.
C)   It's not at all clear what causes most species to become endangered because there are so many factors.
D)   False. We don't really overharvest most economically important resources.
E)   False. This does happen, but we're learning how to harvest sustainably and conservation programs have been successful bring exploited species back from the brink.

Question 16

Sometimes the presence or absence of a particular organism in an ecosystem reflects directly on the health of that ecosystem, sort of like the "canary in the coal mine." What do ecologists call those species?

Accepted Answer

The answer of Sometimes the presence or absence of a...

Question 17

If we want to preserve biodiversity, why is it important to control human population growth?

Accepted Answer

A)   Humans don't care about their habitat.
B)   Humans are such effective competitors for limited resources, we'll take what we need and other species will lose out.
C)   Humans only care about the success of humans.
D)   Humans want to live in tropical rainforests and will take over all that habitat at the expense of other species.
E)   Humans aren't smart enough to manage the Earth in such a way that biodiversity can be preserved.

Question 18

Why is it important to maintain habitat diversity to maintain biodiversity?

Accepted Answer

A)   More varied habitats means more different species are adapted to them and live in them, leading to high species richness and high biodiversity.
B)   A diverse habitat simply contains more individuals, contributing to biodiversity.
C)   The number of species in an area depends on biodiversity.
D)   Higher habitat diversity leads to higher genetic diversity which leads to higher biodiversity.
E)   Widely distributed species need large habitats.

Question 19

When there are many different species living in one habitat, we say that habitat has high what?

Accepted Answer

The answer of When there are many different species living...

Question 20

If we're interested in conserving global biodiversity, why is the fact than tropical rainforests are shrinking dramatically especially bad?

Accepted Answer

A)   Rainforests occupy a lot of territory so if they're shrinking, many species are being lost.
B)   Rainforests are one of the most highly biodiverse ecosystems on Earth, so if they're being lost, many species are being lost.
C)   Unlike most other habitats, it's very difficult to create manmade rainforests.
D)   Rainforests are highly productive, and it's not good to lose that productivity globally.
E)   It's not particularly bad. Every habitat on Earth is equally valuable for biodiversity.

Exam 17: Biodiversity and Human Affairs

What regulating services do intact old-growth forests provide?

Correct AnswerverifiedRetain and...View AnswerShow Answer

All species go extinct. About how long is the average lifespan of a species?

Correct AnswerverifiedShow Answer

The country of Honduras is about the same size as the state of Virginia. Where would you expect to find higher species diversity? Why?

Correct AnswerverifiedShow Answer

The productivity hypothesis says that there is higher species diversity at the equator than toward the poles because the climate is perfect to grow plants. Besides just the volume of food, why might this allow for there to be more species?

Correct AnswerverifiedShow Answer

If we're interested in conserving global biodiversity, why is the fact than tropical rainforests are shrinking dramatically especially bad?

Correct AnswerverifiedShow Answer

How does the theory of island biogeography apply to habitats not on islands?

Correct AnswerverifiedShow Answer

Why are species living on islands more likely to go extinct than those living on the mainland?

Correct AnswerverifiedShow Answer

Deserts in North Africa are very similar to deserts in North America, and so pretty much the same group of species lives in each place.

Correct AnswerverifiedShow Answer

Geographic relief in a region allows for higher biodiversity. What is this?

Correct AnswerverifiedShow Answer

Sometimes the presence or absence of a particular organism in an ecosystem reflects directly on the health of that ecosystem, sort of like the "canary in the coal mine." What do ecologists call those species?

Correct AnswerverifiedShow Answer

If we want to preserve biodiversity, why is it important to control human population growth?

Correct AnswerverifiedShow Answer

Worldwide, diversity of species tends to decrease as you move away from the equator. What do ecologists call this phenomenon?

Correct AnswerverifiedThe latitu...View AnswerShow Answer

What is the most common reason species become endangered?

Correct AnswerverifiedShow Answer

When there are many different species living in one habitat, we say that habitat has high what?

Correct AnswerverifiedShow Answer

Overharvesting of species we consume is the single biggest cause of species becoming endangered. True or false?

Correct AnswerverifiedShow Answer

The controversy between loggers and conservationists in the Pacific Northwest was framed as a fight over an owl, but what was it really about?

Correct AnswerverifiedShow Answer

The model of island biogeography is a mathematical model. How do we know it actually holds true in the "real" world?

Correct AnswerverifiedShow Answer

It appears that humans are a powerful force for extinction. What is this hypothesis called?

Correct AnswerverifiedThe blitzk...View AnswerShow Answer

Why is it important to maintain habitat diversity to maintain biodiversity?

Correct AnswerverifiedShow Answer

To have high species diversity in an ecosystem, you need which of the following combinations?

Correct AnswerverifiedShow Answer

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The latitu...
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The blitzk...
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