Deck 21: Ecosystems

Question 1

Which of the following statements about cycling within an ecosystem is FALSE?

A) Energy is recycled within an ecosystem.
B) Carbon is recycled within an ecosystem.
C) The sedimentary nutrient cycle cycles nutrients very slowly.
D) Human activities affect nutrient cycling.

Answer 1

A

Question 2

All of the living organisms present in an ecosystem comprise the ________ or biotic portion of the ecosystem.

A) community
B) abiotic
C) population
D) biome

Answer 2

A

Question 3

What would happen to nutrient cycling in a forest ecosystem if all of the bacteria,protozoans,fungi,and worms were eliminated?

A) Dead plant and animal matter would accumulate more quickly than it is decomposed, and the soil would become depleted of nutrients.
B) Dead plant and animal matter would decay more rapidly than it is decomposed, and the soil would accumulate nutrients at a faster rate.
C) There would be no discernable change in the rate at which dead plants and animals decompose and no change in the rate of nutrient accumulation in the soil.
D) Dead plant and animal matter would accumulate more quickly than it is decomposed, and the soil would accumulate nutrients at a faster rate.

Answer 3

A

Question 4

Which of the following would be abiotic components of an arctic,marine ecosystem?

A) salt water, ice, snow, sun, wind, rocks, and sand
B) polar bears, seals, salmon, seaweed, and puffins
C) buffalo, meadowlarks, eagles, grasses, and cottonwood trees
D) deer, skinks, squirrels, oak trees, pine trees, and mosses

Question 5

Which of the following groups of organisms would NOT be considered consumers?

A) herbivores
B) predators
C) decomposers
D) photosynthesizers

Question 6

The chemical and physical components of an ecosystem are considered to be ________ or nonliving.

A) abiotic
B) biota
C) biotic
D) abalone

Question 7

Rabbits,foxes,tapeworms,and fungi are all examples of

A) consumers.
B) primary producers.
C) abiotic ecosystem components.
D) photosynthesizers.

Question 8

The primary contribution of decomposers to an ecosystem occurs when they

A) capture solar energy.
B) recycle nutrients sequestered in organisms back to the physical environment.
C) regulate the number of producers.
D) prevent consumer overpopulation.

Question 9

Areas of the ocean that are very cloudy due to large amounts of stirred sediment or eroded soil are likely to experience ________ productivity levels.

A) decreased primary
B) increased primary
C) no change in primary
D) an increase in primary productivity levels with a decrease in secondary

Question 10

In the absence of ________,nutrient recycling within the ecosystem would completely stop.

A) rocks
B) secondary consumers
C) decomposers
D) predators

Question 11

In an ecosystem,energy differs from nutrients in that

A) energy is recycled through photosynthesis, but nutrients are recycled through the atmosphere.
B) nutrients are recycled, but energy eventually moves out of the system and is lost.
C) nutrients are recycled through plant roots, but energy is recycled through leaves.
D) energy is recycled by producers, but nutrients are recycled by consumers.

Question 12

Which of the following are examples of primary producers in a beech-maple woodland?

A) mosses, grasses, beech trees, and maple trees
B) phytoplankton and seaweed
C) phytoplankton, reeds, and marsh grasses
D) squirrels, skinks, deer, and opossums

Question 13

A community of organisms together with the physical environment in which they live is known as a(n)

A) population.
B) community.
C) ecosystem.
D) biota.

Question 14

Almost all life on Earth is directly or indirectly dependent on

A) solar energy.
B) predation.
C) physical productivity.
D) human civilization.

Question 15

A tallgrass prairie or beech-maple woodland are examples of ecologists distinguishing an ecosystem according to the

A) types of producers it contains; this, in turn, establishes the type of consumers that the ecosystem supports.
B) climate in which it is located.
C) type of consumers it contains; this, in turn, establishes the type of producers that the consumers support.
D) daily rainfall amounts; this does not affect the types of consumers or producers present in the ecosystem.

Question 16

Ecologists often define an ecosystem by describing how ________ and ________ are acquired and distributed by the biotic community.

A) energy; nutrients
B) producers; consumers
C) decomposers; consumers
D) nutrients; producers

Question 17

The water in a deep crater in a bay on a tropical island is a striking pure blue color.The water in the surrounding ocean is more of a green color.Which of the following is a logical hypothesis?

A) The water in the bay has a low level of phytoplankton and primary productivity, while there is a higher concentration of phytoplankton in the surrounding ocean.
B) The water in the bay has a high level of phytoplankton and primary productivity, while there is a lower concentration of phytoplankton in the surrounding ocean.
C) The concentration of phytoplankton and primary productivity in the bay and the surrounding ocean is the same, and it is very high.
D) The concentration of phytoplankton and primary productivity in the bay and the surrounding ocean is the same and is almost zero.

Question 18

Which of the following are likely biotic components of a desert ecosystem?

A) sand, sun, and occasional rain
B) cacti, sage brush, scorpions, and snakes
C) oak trees, rhododendrons, squirrels, and moss
D) moss, large pine trees, frogs, and otters

Question 19

Within the ecosystem,nutrients

A) move in a one-way path from producers toward consumers.
B) regularly cycle between organisms and the nonliving environment.
C) are consumed by their use and thus are not available for recycling.
D) are rarely limiting because they are constantly replenished as Earth's crust erodes.

Question 20

Which of the following series best represents the energy flow in an ecosystem?

A) sun → consumer → producer→ metabolic heat
B) consumer → producer → decomposer → sun
C) producer → consumer → decomposer → sun
D) sun → producer → consumer → metabolic heat

Question 21

A decline in phytoplankton could affect the climate of Earth by altering the ________ cycle by moving less ________ from the atmosphere into phytoplankton tissues.Since ________ is a greenhouse gas,more of it in the atmosphere could contribute to global warming.

A) carbon; carbon dioxide; carbon dioxide
B) phosphorous; phosphorous; phosphorous
C) hydrologic; water; water
D) oxygen; oxygen; oxygen

Question 22

If there are 50 kcal of energy in the tertiary consumer trophic level,how many kcal would be expected in the primary consumer level?

A) 50
B) 100
C) 500
D) 5,000

Question 23

Tuna are predatory fish that consume smaller,carnivorous fish that have fed on zooplankton.The zooplankton had fed on phytoplankton.When a person eats tuna,he or she is consuming the ________ trophic level of the food chain.

A) second
B) third
C) fourth
D) first

Question 24

The primary difference between consumers and decomposers is that ________ obtain their nutrients by eating ________,while decomposers obtain their nutrients from ________.

A) consumers; other live organisms; dead consumers
B) consumers; only dead consumers; other live consumers
C) consumers; other live organisms; photosynthesis
D) Consumers and decomposers both obtain their nutrients by eating other live organisms.

Question 25

If a person needs to consume 100 kcal of energy and he chooses to do so by eating soybeans,at least how many kcal of soybeans would have to grow to provide that 100 kcal for the human?

A) 100
B) 1,000
C) 10,000
D) 100,000

Question 26

Energy does not cycle through an ecosystem.This is because energy enters an ecosystem through photosynthesis as it changes to chemical energy.This is then used to fuel metabolic activities in

A) plants only, and all of the excess energy is lost as metabolic heat.
B) consumers only, and all of the excess energy is lost as metabolic heat.
C) decomposers only, and all of the excess energy is lost as metabolic heat.
D) producers, consumers, and decomposers, and all of the excess energy is lost as metabolic heat.

Question 27

If a person needs to consume 100 kcal of energy and she chooses to do so by eating chicken,how many kcal of grain would the chicken need to consume to make 100 kcal available to the human?

A) 1,000
B) 10,000
C) 100,000
D) 1,000,000

Question 28

A grassland ecosystem has 400,000 kcal of energy stored in the primary producer level.Grasshoppers eat the grass,meadowlarks eat the grasshoppers,and a hawk eats the meadowlarks.How many kcals are now stored,and available,in the hawk?

A) 40,000
B) 4,000
C) 400
D) 40

Question 29

There are 5 million kcal of energy stored in grain that could be fed either to chickens or humans.A small village of starving people need to be fed.The most efficient way to feed the majority of the villagers is to feed

A) all of the grain to the villagers.
B) all of the grain to chickens and let the villagers eat the eggs.
C) all of the grain to chickens and let the villagers eat the chickens.
D) some of the grain to chickens and some of it to villagers.

Question 30

In the absence of ________,nutrients would not move from the abiotic to the biotic portion of the nutrient cycle within an ecosystem.

A) primary producers
B) herbivores
C) carnivores
D) omnivores

Question 31

When humans consume rice,they occupy which trophic level of a food chain?

A) primary consumer
B) secondary consumer
C) tertiary consumer
D) primary producer

Question 32

Human activities

A) rarely affect nutrient cycles.
B) can alter nutrient cycles on local and global scales.
C) tend to cause only local changes in nutrient cycles.
D) generally improve nutrient cycling in ecosystems.

Question 33

There are 5 million kcal of energy stored in grain that could be fed either to beef cattle or humans.A farmer chooses to feed the grain to the cattle to fatten them up for human consumption.How many kcal would now be available as beef to feed the humans?

A) 500,000
B) 50,000
C) 5,000
D) 500

Question 34

Your spacecraft crash-lands on an airless,lifeless moon.All that survives,along with the crew and you,are some chickens,cornflakes,and vitamins.The air and water recyclers are functioning.To maximize the food supply until a rescue craft arrives,you and the crew should

A) feed the cornflakes and vitamins to the chickens, then eat the eggs until rescued.
B) kill all the chickens immediately, eat them first, and then eat the cornflakes.
C) mark each week's survival by eating one chicken.
D) share the cornflakes with the chickens and eat a chicken each day. When the chickens are all eaten, shift to eating whatever cornflakes are left.

Question 35

The ultimate disposition of most energy in an ecosystem

A) is used to construct the bodies of decomposers.
B) is trapped as fossil fuels when producers die and become fossilized.
C) is continuously recycled back into the ecosystem.
D) eventually returns to space in the form of heat.

Question 36

When humans consume herbivores such as cattle,they occupy which trophic level of a food chain?

A) primary consumer
B) secondary consumer
C) tertiary consumer
D) primary producer

Question 37

In the diagram below,how do nutrient and energy flow differ?

A) Energy flow is one-way, whereas nutrients are recycled.
B) Energy is recycled, whereas nutrient flow is one-way.
C) Only about 10 percent of energy flows from trophic level to trophic level. Nutrient flow is 100 percent from trophic level to trophic level.
D) Energy flows only to primary producers and decomposers, whereas nutrients flow only to secondary consumers and decomposers.

Question 38

Tuna are predatory fish that consume smaller,carnivorous fish that have fed on zooplankton.The zooplankton had fed on phytoplankton.When a human eats tuna,that person is the ________ trophic level of the food chain.

A) second
B) third
C) fourth
D) fifth

Question 39

On average,what percentage of the energy from one trophic level of an energy pyramid is transferred to the next trophic level?

A) 10 percent
B) 33 percent
C) 50 percent
D) 90 percent

Question 40

If there are 20,000 kcal available in the primary producer level of an ecosystem,how many kcal would be available in the secondary consumer level?

A) 200
B) 20
C) 2
D) 2,000

Question 41

Other than the polar tundra,the LEAST productive terrestrial biomes tend to be

A) deserts.
B) temperate forests.
C) tropical forests.
D) estuaries.

Question 42

What best explains the following observation: consumers directly use approximately 20 percent of a forest's net primary productivity (NPP),whereas decomposers directly use approximately 80 percent?

A) Decomposers are more efficient at obtaining energy than consumers.
B) Forest ecosystems do not have a very high NPP, so they cannot support as many consumers as other ecosystems can.
C) Consumers eat only certain parts of organisms, such as fruits or muscle tissue, whereas decomposers obtain energy from the entire body of the food organism.
D) Secondary consumers eat the primary consumers more quickly than the primary consumers can eat the producers, thus leaving most of the NPP available to the decomposers.

Question 43

Several research teams have questioned Daniel Boyce's data that indicates a loss of 500 million tons of phytoplankton a year from Earth's oceans.Is it important for researchers to accurately determine trends in net primary productivity (NPP)in the oceans because

A) there are similarities between the NPP requirements on land and in the ocean.
B) there are no similarities between the NPP requirements on land and in the ocean.
C) the loss of 500 million tons of phytoplankton each year could have a negative effect on the ocean's NPP and all of the ocean life that depends upon it.
D) the loss of 500 million tons of phytoplankton each year could have a positive effect on the ocean's NPP and all of the ocean life that depends upon it.

Question 44

A variety of species living together and interacting with each other in a defined place form an ________.

Question 45

Why are deserts and tundra among the least productive terrestrial biomes?

A) Water is not easily accessible by plants in desert and tundra biomes, and both of these biomes experience extreme temperature conditions. Water availability and temperature are important limiting factors in net primary productivity (NPP).
B) There is too much water available in the tundra and not enough available in the desert. The extreme temperatures of these biomes do not affect NPP.
C) There is not enough sunlight available in either the tundra or the desert biomes to sufficiently support NPP.
D) There is far too much sunlight and water available in both the desert and tundra biomes. These factors cause photosynthesis to be suspended and result in dramatically decreased NPP.

Question 46

Ecologists often define an ecosystem with regard to how BOTH ________ are acquired and distributed by the biotic community.

Question 47

Between late 1997 and mid-2008,satellites observed that warmer-than-average ocean temperatures led to below-average chlorophyll concentrations in the oceans.This finding suggests that continued warming of Earth's oceans could lead to a(n)________ in net primary productivity in the oceans,and the oceans would,therefore,remove ________ carbon dioxide from the atmosphere.

A) decrease; less
B) increase; less
C) decrease; more
D) increase; more

Question 48

To best use Earth's net primary productivity to feed the most people,diets should be modified to include only ________,moving ________ the food chain and gathering the maximum amount of energy available from a given biomass of producers.

A) meat; higher up
B) meat; lower down
C) plant material; lower down
D) plant material; higher up

Question 49

An ecosystem that experiences a small increase in nutrients available to primary producers is likely to show

A) an increase in net primary productivity.
B) a decrease in net primary productivity.
C) no change in net primary productivity.
D) a decrease in net primary productivity followed by an immediate return to average net primary productivity.

Question 50

Other than tropical forests,the most productive biomes tend to be

A) estuaries.
B) deep oceans.
C) deserts.
D) tundra.

Question 51

The figure below shows the net primary productivity (NPP)in marine biomes around the world with the darkest areas being the most productive.The pattern of NPP in marine ecosystems as shown suggests that

A) marine productivity is as sensitive to temperature as terrestrial productivity.
B) without shade from overhead vegetation, marine productivity typically exceeds that found in terrestrial ecosystems.
C) marine ecosystems are also limited by sunlight, with the highest productivity at the equator.
D) most marine productivity results from the input of terrestrially derived nutrients.

Question 52

Ecologists use a(n)________ to represent the amount of energy available to organisms in an ecosystem.

Question 53

Each level of an energy pyramid corresponds to a step in a food chain and is called a(n)________ level.

Question 54

As shown in the figure below,the net primary productivity (NPP)in terrestrial biomes around the world is greatest in areas near the Equator that also receive high amounts of yearly rainfall.This pattern of NPP in terrestrial ecosystems suggests that

A) terrestrial productivity is highly sensitive to temperature and available sunlight.
B) without shade from overhead vegetation, marine productivity typically exceeds that found in terrestrial ecosystems.
C) neither sunlight nor temperature limits terrestrial ecosystems.
D) most terrestrial productivity results from the input of marine-derived nutrients.

Question 55

Producers capture energy from the ________ and transform it into fuel energy that passes up the food chain as one organism eats another.

Question 56

Which of the following is NOT an easily testable hypothesis regarding net primary productivity?

A) An increase in temperature will likely result in an increase of net primary productivity (NPP) in some terrestrial ecosystems.
B) An increase in temperature will likely result in an increase of NPP in some marine ecosystems.
C) An increase in available sunlight will likely result in an increase of NPP in some marine and terrestrial ecosystems.
D) An increase of water in a marine ecosystem will likely result in tastier products of NPP.

Question 57

Chemical elements required by living organisms are BOTH ________ within and across ecosystems.

Question 58

In marine ecosystems,net primary productivity tends to be

A) greater along shorelines where terrestrial nutrients enter the marine environment.
B) lower where the oceans border land because terrestrial pollution suppresses marine productivity.
C) lowest in areas where upwelling brings colder water to the surface.
D) greater than the net primary productivity on land.

Question 59

At each trophic level,a portion of the energy originally captured by producers is lost as ________,typically released as a by-product of cellular respiration.

Question 60

A group of living communities interacting with one another and their shared physical environment is a(n)________.

Question 61

The units used in the infographic below report total energy available from primary producers in indicated biomes in ________.

Question 62

Compare and contrast grassy marsh wetlands to bogs and explain why one of these freshwater biomes is more productive than the other.

Question 63

Strict vegetarians,or vegans,would be considered ________ consumers in an energy pyramid.

Question 64

Explain how energy enters and progresses through a food chain.

Question 65

Explain the difference in net primary productivity (NPP)between temperate grasslands and tropical grasslands.Include data units.

Question 66

Using the food chain shown below,explain how many calories are available in the consumer trophic levels and why.

Question 67

Describe how chemical nutrients enter and are recycled through an ecosystem.

Question 68

Describe what estuaries are,where they can be found,their relative productivity,and the reasons for their productivity level.

Question 69

Why don't ecosystems always have sharply defined physical boundaries?

Question 70

Propose an explanation for why whales swimming up and down through the water column in the ocean ecosystem can help remove tons of carbon dioxide from the atmosphere each year.

Question 71

Explain why only roughly 10 percent of the energy available in one trophic level is available in the next higher trophic level.

Question 72

The amount of energy captured by photosynthetic organisms,minus the amount lost as heat from respiration and other life processes,is called ________.

Question 73

Should the scientific community accept,without questions,Boyce,Worm,and Lewis's hypothesis that Earth's oceans are losing 500 million tons of phytoplankton per year? Support your answer.

Question 74

The shallowest but most productive of the aquatic biomes are ________.These tidal ecosystems exist where rivers flow into the ocean.

Question 75

How and why does the global pattern of net primary productivity (NPP)differ between the oceans and terrestrial ecosystems?

Question 76

Regions of Earth that are defined by their unique climatic and ecological features are known as ________.The flora and fauna residing there are particularly adapted to the climate and defining ecological features.

Question 77

On what four factors does net primary productivity rely,and what terrestrial ecosystem is the most productive because of these factors?

Question 78

Since 1931,the phytoplankton biomass in the Northeast Atlantic Ocean has been monitored by the __________ (CPR)survey where a special instrument is pulled through the ocean by commercial fishing vessels to collect millions of sample of plankton.

Question 79

Use examples to explain how an ecological community differs from an ecosystem.

Question 80

Assessing the overall net primary productivity (NPP)of an ecosystem is important in determining how an ecosystem works,because ________ capture influences the amount of food available to other organisms in the ecosystem.