Question 1

Explain how the world's food supply may be affected by whether people eat primarily meat or vegetables.

Accepted Answer

The answer of Explain how the world's food supply may...

Question 2

In an area with nitrogen- poor soil, legumes often dominate over other plants because they

Accepted Answer

A)  have long taproots that can extract nitrogen from deeper down in the soil. 
B)  have unique access to the large atmospheric pool of nitrogen thanks to their symbiotic bacteria. 
C)  inhibit the growth of denitrifying bacteria around their roots, thus keeping more nitrate in the soil. 
D)  do not need nitrogen at all. 
E)  obtain supplemental nitrogen by trapping insects and other prey.

Question 3

Organisms that produce their own food from inorganic compounds through reactions powered by sunlight are heterotrophs.

Accepted Answer

A) True 
 B)False

Question 4

Sulfur dioxide is a natural product of volcanoes and hot springs, and by itself, it is not acidic. How, then, is excess sulfur dioxide linked to acid rain or acid deposition?

Accepted Answer

The answer of Sulfur dioxide is a natural product of...

Question 5

The present range of the sugar maple in North America extends from the Atlantic Ocean west to the Mississippi River and from southern Ontario, Quebec, and New Brunswick south to Tennessee and Virginia. If the global temperature rises 10°C in the future, where will the range of sugar maples be found?

Accepted Answer

A)  Farther west 
B)  Farther south 
C)  Farther north 
D)  In the same place; global warming will not affect the heat tolerance of plants. 
E)  Nowhere; sugar maples will become extinct.

Question 6

Which level of the energy pyramid has the greatest biomass?

Accepted Answer

A)  Heterotrophs 
B)  Primary consumers 
C)  Secondary consumers 
D)  Producers 
E)  Carnivores

Question 7

When you observe a lake that has been affected by acid deposition, you might expect to find

Accepted Answer

A)  excess carbon that will contribute to global warming. 
B)  low levels of toxic metals and nutrients essential for the growth of biotic organisms. 
C)  a clear lake with high levels of aluminum, mercury, and lead, but few fish. 
D)  high levels of dissolved sulfur dioxide. 
E)  a murky lake with excess algal growth from the deposition of anthropogenic nitrogen.

Question 8

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

Accepted Answer

A)  nitrogen precipitation. 
B)  acid fog. 
C)  decomposition acid. 
D)  acid deposition. 
E)  acid precipitation.

Question 9

Autotrophs gain energy from

Accepted Answer

A)  secondary consumers. 
B)  the sun and inorganic nutrients. 
C)  omnivores. 
D)  secondary producers. 
E)  primary producers.

Question 10

Ornithologists have noted that Mexican Jays in Arizona are nesting 10 days earlier in the springtime today than t in the 1970s. They suggest that this behavior is evidence of
.

Accepted Answer

The answer of Ornithologists have noted that Mexican Jays in...

Question 11

On a field trip with your class to mountain lakes in Vermont, you come across a beautiful clear lake that is deep, and you can see the pebbles at its bottom. Why does your classmate hypothesize that this lake has been subjected to acidic deposition?

Accepted Answer

The answer of On a field trip with your class...

Question 12

Iron is a limiting factor in many aquatic ecosystems. If the iron level is increased, the amount of phytoplankton (which feed on iron) decreases.

Accepted Answer

A) True 
 B)False

Question 13

The are an important and often overlooked group of organisms that release nutrients into the soil or water.

Accepted Answer

A)  heterotrophs 
B)  decomposers 
C)  autotrophs 
D)  tertiary consumers 
E)  producers

Question 14

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

Accepted Answer

A)  nitrogen the fish brought from the ocean and contained in their tissues has been lost. 
B)  dams that prevented the fish from migrating also flooded the forests. 
C)  fishers who overharvested the salmon compacted the soil in the process. 
D)  global warming that wiped out the fish has also harmed the trees. 
E)  pollution that killed the fish has also directly affected the trees.

Question 15

A snake that eats a small rabbit that feeds on grass is classified as a(n)

Accepted Answer

A)  primary producer. 
B)  primary consumer. 
C)  secondary consumer. 
D)  autotroph. 
E)  tertiary consumer.

Question 16

Deforestation decreases the levels of greenhouse gases in the atmosphere.

Accepted Answer

A) True 
 B)False

Question 17

Certain bacteria and fungi that are important in nutrient recycling because they release nutrients from dead organisms back into the ecosystem are

Accepted Answer

A)  recyclers. 
B)  detritus feeders. 
C)  carnivores. 
D)  decomposers. 
E)  autotrophs.

Question 18

A carnivorous plant, such as a sundew, may be considered both a when it eats a carnivorous spider.

Accepted Answer

A)  primary consumer and a secondary consumer 
B)  primary consumer and a tertiary consumer 
C)  producer and a tertiary consumer 
D)  producer and a secondary consumer 
E)  producer and a primary consumer

Question 19

Net primary production is

Accepted Answer

A)  heterotrophic production minus autotrophic production per unit of land per unit of time. 
B)  energy made by autotrophs minus energy consumed by heterotrophs, and measured as biomass. 
C)  energy that photosynthetic organisms make available to other organisms over a given period of time. 
D)  energy stored by secondary consumers from primary biomass. 
E)  heterotrophic production per unit of land per unit of time.

Question 20

The level of environmental toxins such as DDT decreases as you move into the higher trophic levels.

Accepted Answer

A) True 
 B)False

Exam 29: Energy Flow and Nutrient Cycling in Ecosystems

Explain how the world's food supply may be affected by whether people eat primarily meat or vegetables.

In an area with nitrogen- poor soil, legumes often dominate over other plants because they

Organisms that produce their own food from inorganic compounds through reactions powered by sunlight are heterotrophs.

Sulfur dioxide is a natural product of volcanoes and hot springs, and by itself, it is not acidic. How, then, is excess sulfur dioxide linked to acid rain or acid deposition?

Which level of the energy pyramid has the greatest biomass?

When you observe a lake that has been affected by acid deposition, you might expect to find

When nitrogen oxides and sulfur dioxide combine with water vapor in the air, they are converted to nitric acid and sulfuric acid, respectively. This precipitation that then falls to the Earth is known as

Autotrophs gain energy from

Ornithologists have noted that Mexican Jays in Arizona are nesting 10 days earlier in the springtime today than t in the 1970s. They suggest that this behavior is evidence of .

On a field trip with your class to mountain lakes in Vermont, you come across a beautiful clear lake that is deep, and you can see the pebbles at its bottom. Why does your classmate hypothesize that this lake has been subjected to acidic deposition?

Iron is a limiting factor in many aquatic ecosystems. If the iron level is increased, the amount of phytoplankton (which feed on iron) decreases.

The are an important and often overlooked group of organisms that release nutrients into the soil or water.

Forests along rivers in the Pacific Northwest that have lost their salmon populations are less productive because the

A snake that eats a small rabbit that feeds on grass is classified as a(n)

Deforestation decreases the levels of greenhouse gases in the atmosphere.

Certain bacteria and fungi that are important in nutrient recycling because they release nutrients from dead organisms back into the ecosystem are

A carnivorous plant, such as a sundew, may be considered both a when it eats a carnivorous spider.

Net primary production is

The level of environmental toxins such as DDT decreases as you move into the higher trophic levels.