Chapter 17: Ecosystems and Communities

Question 1

An ecosystem:

1. is composed of the plant life and climate of a given area.
2. consists of all of the living and non-living things functioning together in an area.
3. consists of all of the living animals in a given area.
4. consists of all of the living organisms in a given area.
5. is composed of all of the abiotic factors that influence living organisms in a given area.

Answer 1

consists of all of the living and non-living things functioning together in an area

Question 2

Omnivores:

1. subsist on dead matter and waste products of other organisms.
2. may exist at any trophic level.
3. feed primarily on primary producers.
4. are never found in the first trophic level.

Answer 2

are never found in the first trophic level

Question 3

What is (are) the main reason(s) the tropics are warmer than the poles?

1. The sun’s rays hit earth directly at the equator but hit the poles at an angle; this concentrates the solar energy over a smaller area at the equator than at the poles.
2. When sunlight hits the equator, it passes through less atmosphere, thus losing less energy than it does when passing through more atmosphere at the poles.
3. The poles are significantly farther away from the sun than the equator, thus they receive less solar energy.
4. All of the above are correct.

Answer 3

The sun’s rays hit earth directly at the equator but hit the poles at an angle; this concentrates the solar energy over a smaller area at the equator than at the poles

Question 4

Which of the following biomes has the highest average annual temperature?

1. savanna
2. temperate grasslands
3. temperate evergreen forests
4. tundra
5. temperate deciduous forests

Answer 4

savanna

Question 5

“Food chains are accurate representations of energy flow through an ecosystem.” This statement is:

1. true; food chains accurately illustrate existing trophic levels.
2. false; real ecosystems are much more complex than simplified food chains.
3. false; the idea of producers, herbivores, and carnivores are human constructs.
4. true; however, they do not represent the amount of energy flowing through an ecosystem.
5. false; food chains depict organism diets, not energy flow.

Answer 5

false; real ecosystems are much more complex than simplified food chains

Question 6

The PRIMARY reason for differences in climate at different places on earth is:

1. that the earth is shaped like a pear and not a sphere.
2. that different places receive different amounts of solar energy.
3. that every place on earth receives the same total hours of sunlight.
4. that different places have different thicknesses of the atmosphere.
5. that different places receive different amounts of thermal energy.

Answer 6

that different places receive different amounts of solar energy

Question 7

Even though there is a carbon cycle, it now appears that CO2 levels are rising around the world. Which of the following best explains this?

1. The destruction of coral reefs leads to increased levels of CO2.
2. More CO2 is being given off by ocean waters as they heat up.
3. The burning of fossil fuels releases large amounts of CO2, thus increasing the average concentration of CO2 in the atmosphere.
4. As the atmosphere heats up, it can contain more CO2.
5. Animals give off CO2 during their normal metabolism

Answer 7

The burning of fossil fuels releases large amounts of CO2, thus increasing the average concentration of CO2 in the atmosphere

Question 8

The American Kestrel (Falco sparverius) and the Common Kestrel (Falco tinnunculus) are found on different continents; however, both hunt for small mammals and birds in open country. Therefore, these two species:

1. occupy similar niches.
2. are sympatric.
3. are paraphyletic.
4. competitively inhibit one another.
5. exhibit character displacement.

Answer 8

occupy similar niches

Question 9

Which of the following is an example of mutualism?

1. A remora fish removes harmful algae and parasites from a shark’s skin, and receives protection in return.
2. A jaguar kills and consumes a gazelle.
3. The cattle egret feeds on insects stirred up by a grazing cape buffalo.
4. A wasp paralyzes a caterpillar and lays its egg inside it.
5. A female cuckoo lays its egg in the nest of a smaller bird, which then raises the cuckoo chick.

Answer 9

A remora fish removes harmful algae and parasites from a shark’s skin, and receives protection in return

Question 10

Coevolution:

1. is responsible for all nectar production by plants.
2. reveals that both biotic and abiotic resources can serve as selective forces.
3. is responsible for all of the beautiful flowers in the world.
4. can produce an insect with a tongue as long as its body.
5. All of the above are correct.

Answer 10

All of the above are correct

Question 11

Which statement about the 10% rule of energy conversion efficiency is NOT true?

1. It limits the length of food chains.
2. It suggests that 90% of what an organism eats is used in cellular respiration or is lost as feces.
3. It suggests that 10% of what an organism eats is used in cellular respiration or is lost as feces.
4. It explains why big, fierce animals are so rare.
5. It explains why herbivore biomass must exceed that of carnivores.

Answer 11

It suggests that 10% of what an organism eats is used in cellular respiration or is lost as feces

Question 12

The total dry weight of all organisms in an ecosystem is called its:

1. net productivity.
2. biodiversity.
3. biomass.
4. flow-through energy.
5. productivity.

Answer 12

biomass

Question 13

Nitrogen enters the food chain:

1. primarily through soil-dwelling bacteria that “fix” it by attaching it to other atoms.
2. from the atmosphere when “fixed” by the photosynthetic machinery of plants.
3. through methane produced by herbivores as a by-product of the breakdown of plant material.
4. when rocks dissolved by rainwater become soil and are utilized by plants as they grow.
5. through soil erosion followed by runoff into streams and ponds.

Answer 13

primarily through soil-dwelling bacteria that “fix” it by attaching it to other atoms

Question 14

A driving force behind ocean currents is:

1. global wind circulation.
2. the salinity gradient in the ocean.
3. the oxygen gradient in the ocean.
4. the Coriolis effect

Answer 14

global wind circulation

Question 15

The main source of energy that drives global climate is:

1. geothermal energy.
2. chemical energy.
3. solar energy.
4. ocean currents.
5. wind power.

Answer 15

solar energy

Question 16

If a food chain consisted of grass to rabbits to foxes, how many pounds of foxes could be expected in a meadow that has 10,000 pounds of grass?

1. 100,000
2. 10
3. 10,000
4. 2,000
5. 100

Answer 16

100

Question 17

Without ocean currents such as the Gulf Stream, the climate of the United Kingdom would:

1. be much more moderate.
2. remain the same.
3. be similar to that of Scandinavia.
4. be similar to that of the Mediterranean.
5. fluctuate drastically with the seasons.

Answer 17

be similar to that of Scandinavia

Question 18

Most of the carbon in earth’s atmosphere exists as:

1. carbon tetrachloride, CCl4.
2. chlorofluorocarbons, CFCs.
3. carbonic acid, H2CO3.
4. methane, CH4.
5. carbon dioxide, CO2.

Answer 18

carbon dioxide, CO2

Question 19

The monarch butterfly uses ___________________ as a defense for reducing predation.

1. warning coloration
2. alarm calling
3. quills
4. camouflage
5. escape

Answer 19

warning coloration

Question 20

Most of the deserts of the world are:

1. in tropical Africa and South America.
2. at 30° N and S latitude.
3. in arboreal highlands.
4. in the Arctic and Antarctic circles.
5. in Oceana.

Answer 20

at 30° N and S latitude