Question 1

Figure 42.3
-In the diagram of the nitrogen cycle in Figure 42.3,which number represents nitrogen-fixing bacteria?

Accepted Answer

A) 5 
B) 6 
C) 7 
D) 1

Question 2

What is the goal of restoration ecology?

Accepted Answer

A) to replace a ruined ecosystem with a more suitable ecosystem 
B) to initiate or accelerate the restoration of a degraded ecosystem 
C) to completely restore a disturbed ecosystem to its former state 
D) to prevent further degradation by protecting an area with park status 
E) to manage competition between species in human-altered ecosystems

Question 3

Climatic factors such as temperature and rainfall affect net primary production (NPP).Which of the following climate-related events led to an increase in NPP in terrestrial ecosystems?

Accepted Answer

A) severe droughts in the American Southwest 
B) bark beetle infestations in white pine forests 
C) wildfires in the Yellowstone National Park 
D) decreased cloud cover in Amazon rain forests 
E) increased phosphorous in the Atlantic Ocean

Question 4

Figure 42.3
-In the diagram of the nitrogen cycle in Figure 42.3,which number represents the activity of nitrifying bacteria converting ammonium to nitrate?

Accepted Answer

A) 5 
B) 6 
C) 7 
D) 3

Question 5

Trophic efficiency basically measures the efficiency of energy transfer.Which of the following is most correct in illustrating a measurement of trophic efficiency?

Accepted Answer

A) 9% of energy passed from a primary consumer to a tertiary consumer 
B) 5% of energy passed from a primary producer to a secondary consumer 
C) 12% of energy passed from a primary producer to a primary consumer 
D) 7% of energy passed from a tertiary consumer to a primary consumer 
E) 10% of energy passed from a primary consumer to a primary producer

Question 6

It is well known that animals at higher trophic levels are vulnerable to extinction.Which of the following factors is most likely to increase the likelihood of extinction?

Accepted Answer

A) increased dry mass at higher trophic levels 
B) increased energy transfer at higher levels 
C) the same energy transfer at all levels 
D) decreased energy transfer at higher levels 
E) decreased dry mass at higher trophic levels

Question 7

Secondary production is

Accepted Answer

A) energy conversion by secondary consumers received from primary consumers. 
B) solar energy that is converted to chemical energy by photosynthetic producers. 
C) chemical energy in food that is converted to new biomass by consuming organism. 
D) energy that is transferred when not used by consumers for growth and reproduction. 
E) growth that takes place during the second year of life in heterotrophic consumers.

Question 8

If the sun were to suddenly stop providing energy to Earth,most ecosystems would vanish.Which of the following ecosystems would likely survive the longest after this hypothetical disaster?

Accepted Answer

A) Brazilian rain forest ecosystem 
B) Antarctic tundra ecosystem 
C) Pacific deep-sea vent ecosystem 
D) African grassland ecosystem 
E) California desert ecosystem

Question 9

After Hurricane Katrina,sunflowers and other plants were planted to selectively remove contaminants from the soil.Once the plants matured,they were pulled up by the roots and safely stored with other contaminated wastes.This is an example of

Accepted Answer

A) biological augmentation. 
B) reducing primary production. 
C) lowering production efficiency. 
D) detoxification by phytoremediation. 
E) obstruction of nutrient cycling.

Question 10

The number of trophic levels is typically limited to four or five.Which of the following is primarily responsible for this limitation?

Accepted Answer

A) Many primary and higher-order consumers are opportunistic feeders. 
B) Decomposers compete with higher-order consumers for nutrients and energy. 
C) Nutrient cycles involve both abiotic and biotic components of ecosystems. 
D) Nutrient cycling rates tend to be limited by decomposition by detritivores. 
E) Energy transfer between trophic levels tends to be of very low efficiency.

Question 11

Figure 42.2 Diagram of a food web (arrows represent energy flow and numbers represent species)
-If Figure 42.2 represents a marine food web,the simplest organism might be

Accepted Answer

A) 1. 
B) 6. 
C) 3. 
D) 9. 
E) 5.

Question 12

The amount of chemical energy in a consumer's food that is converted to its own new biomass during a given time period is known as which of the following?

Accepted Answer

A) tertiary production 
B) quaternary production 
C) primary production 
D) secondary production

Question 13

The measures of net primary production (NPP)and net ecosystem production (NEP)both can be used to quantify gross primary production (GPP).Which of the following most correctly explains a difference between these two measures?

Accepted Answer

A) NPP measures GPP minus the energy used by all heterotrophs. 
B) NEP measures GPP minus the energy used by all autotrophs. 
C) NPP measures GPP minus the energy used by primary producers. 
D) NEP measures GPP minus the energy used by primary consumers. 
E) NPP measures GPP minus the energy used by all detritivores.

Question 14

What is the amount of secondary production described in this scenario?

Accepted Answer

A) 100 g 
B) 85 g 
C) 15 g 
D) 1 g 
E) 0.15 g

Question 15

A cow's herbivorous diet indicates that it is a(n)

Accepted Answer

A) primary consumer. 
B) secondary consumer. 
C) chemotrophic animal. 
D) autotrophic animal. 
E) primary producer.

Question 16

What percentage of visible light striking a plant is converted into chemical energy?

Accepted Answer

A) 1% 
B) 10% 
C) 25% 
D) 50% 
E) 100%

Question 17

Aquatic primary productivity is most limited by which of the following?

Accepted Answer

A) light and nutrient availability 
B) predation by primary consumers 
C) increased pressure with depth 
D) unregulated industrial pollution 
E) global increases in temperature

Question 18

Rain falls on a fertilized agricultural field after a farmer has harvested the corn.Which biogeochemical cycles are involved when runoff from the field flows into a nearby stream?

Accepted Answer

A) only carbon and water 
B) only water and nitrogen 
C) only carbon,nitrogen,and phosphorus 
D) only water,nitrogen,and phosphorus

Question 19

The major role of detritivores in ecosystems is to

Accepted Answer

A) provide an organic nutritional resource for heterotrophic organisms. 
B) recycle chemical matter to a form capable of being used by autotrophs. 
C) prevent the buildup of the remains of organisms at all trophic levels. 
D) convert organic matter to energy previously lost by the ecosystem.

Question 20

Which of these ecosystems accounts for the largest amount of Earth's net primary productivity?

Accepted Answer

A) Antarctic tundra 
B) African savanna 
C) Florida salt marsh 
D) Pacific open ocean 
E) Bolivian rain forest

Exam 42: Ecosystems and Energy

Figure 42.3 -In the diagram of the nitrogen cycle in Figure 42.3,which number represents nitrogen-fixing bacteria?