Deck 11: The Flux of Energy and Matter Through Ecosystems

Question 1

You have been informed that terrestrial plants produce 45-60 petragrams of carbon per year,and that this figure accounts for respiratory heat lost from the environment by autotrophs.What then is this 45-60 petragrams of carbon per year a measure of?

A) Biomass
B) Standing crop
C) Rauto
D) Net primary productivity

Answer 1

D

Question 2

Which of the following terms refers to the mass of organisms per unit area?

A) Gross primary productivity
B) Biomass
C) Standing crop
D) Carrying capacity

Answer 2

B

Question 3

Which of the following choices explains what a standing crop of biomass is?

A) A standing crop is the seed bank, the number of potential living plants within a unit area.
B) A standing crop of living organisms within a unit area.
C) A standing crop is the megafauna of a unit area.
D) A standing crop is the number of plants in an agricultural plot of land that ended up bearing a food resource product.

Answer 3

B

Question 4

Which of the following choices refers to the rate of production of biomass by heterotrophs?

A) Biomass
B) Net primary productivity
C) Net ecosystem productivity
D) Secondary productivity

Question 5

Which community would you suspect receives high levels of radiation but does not convert much of that radiation to biomass?

A) Tropical rain forest in Costa Rica
B) Tropical rain forest in Ecuador
C) Death Valley desert in California, United States of America
D) A conifer forest in Alberta, Canada

Question 6

If you were given a measure of the total fixation of energy via photosynthesis,you would have which?

A) Primary productivity
B) Rauto
C) Gross primary productivity
D) Secondary productivity

Question 7

What would be considered a high level of net photosynthetic efficiency for a naturally occurring ecosystem?

A) 30% efficiency
B) 10% efficiency
C) 3% efficiency
D) 0.01% efficiency

Question 8

What does net primary productivity represent?

A) The actual amount of new biomass available for heterotrophs to consume
B) The actual rate at which new biomass is produced for heterotrophs to consume
C) The actual number of new living organisms in a unit area for heterotrophs to consume
D) The actual productivity of an ecosystem and how much respiration occurs over time.

Question 9

Which biome has the greatest overall NPP?

A) Tropical rain forest
B) Tundra
C) Tropical savanna
D) Temperate forest

Question 10

Which of the following choices refers to the rate of production of new biomass that would be available for consumption by bacteria,fungi,or animals?

A) Net primary productivity
B) Gross primary productivity
C) Secondary productivity
D) Net ecosystem productivity

Question 11

According to Figure 11.1,where is the annual average rate of net primary productivity greater?

A) Between 30 degrees north and the equator
B) Between 30 degrees south and the equator
C) Between 30 degrees north and 60 degrees north
D) Between 30 degrees south and 60 degrees south

Question 12

If the cumulative mass of organisms in a biome was hypothetically held constant,but the area of the biome was reduced,how would biomass be affected?

A) It would not be affected
B) Biomass would decrease because it is proportional to area
C) Biomass would increase because it is per unit area
D) Biomass would decrease because it is per unit area

Question 13

Which of the following statements is accurate regarding the total potential rate of net primary productivity (NPP)of Earth's natural ecosystems?

A) Almost all NPP is produced in terrestrial ecosystems
B) Almost all NPP is produced in the oceans
C) Slightly more NPP is produced in terrestrial ecosystems and slightly less NPP is produced in the oceans
D) NPP is equal between terrestrial ecosystems and the oceans.

Question 14

Which terms would be important to an ecologist when measuring primary productivity?

A) Net primary productivity only since all that is important is the actual rate of decomposition of biomass.
B) Gross primary productivity because all that is important is the total amount of energy gained after photosynthesis.
C) Net primary productivity and gross primary productivity because net primary productivity tells you the rate of new biomass produced and gross primary productivity tells you the total fixation of energy via photosynthesis.
D) Only primary productivity; there is no need for an ecologist to look at net or gross primary productivity.

Question 15

Where would photosynthetic efficiency be lowest?

A) A conifer forest
B) A deciduous forest
C) A tropical rain forest
D) A desert

Question 16

Plants respire a proportion of the total amount of energy they fix during photosynthesis.How is this accounted for when considering productivity?

A) The proportion is subtracted from the biomass
B) Rauto is the term used to account for this proportion of energy lost
C) The proportion is added to the total biomass
D) No energy is lost during the process of photosynthesis

Question 17

A graduate student has told you that the average net primary productivity (NPP)per area is greater on land than in oceans despite the fact that their total NPP potential is the same.What is one possible reason for this difference?

A) Terrestrial systems always have the highest NPP because terrestrial animals need to consume more biomass than oceanic organisms
B) She is not correct. Oceans will always have the highest NPP because there is such an abundance of phyto- and zoo- plankton
C) Per area, land will have an average NPP greater than oceans because oceans cover much more of Earths total area
D) The NPP per area is equal between land and ocean

Question 18

In which ecosystem is phosphorous usually most limiting?

A) Boreal forest
B) Tundra
C) Atlantic forest
D) Tropical forest

Question 19

Which of the following is an accurate definition of primary productivity?

A) The rate at which a standing crop is produced or the volume at which plants photosynthesize.
B) The rate at which biomass is produced per unit area or volume through photosynthesis
C) The formation of essential plant structures
D) The rate of formation of essential plant structures over a photosynthetic period.

Question 20

If an oak tree loses its leaves,what happens to the productivity of that tree?

A) Its productivity is zero
B) Nothing happens to its rate of productivity
C) Its productivity is halved
D) It produces a module

Question 21

Which continent has the highest rate of nitrogen fixation?

A) North America
B) Europe
C) Australia
D) South America

Question 22

Which two general systems describe how net primary productivity is used by organisms?

A) Deep sea conveyor system
B) Live consumer system
C) Decomposer system
D) Terrestrial consumer system

Question 23

According to Figure 11.10,which part of North America has a greater rate of nitrogen fixation?

A) The Gulf of Mexico
B) The Pacific Northwest
C) New England
D) The Great Lakes

Question 24

Which of the following is an explanation as to why cyanobacteria blooms are prevented in oceans?

A) High availability of sulfate increases the rate of cyanobacteria growth, but abundance is grazed upon by zooplankton
B) Net primary productivity is low in all ocean zones and that prevents cyanobacteria blooms
C) A low availability of moldybenum in seawater slows the growth of cyanobacteria, which in turn grazing by zooplankton is sufficient to prevent blooms
D) All of the above

Question 25

A nitrogen to phosphorous ratio by moles of 15:1 is often termed which of the following?

A) The Redford ratio
B) Net primary productivity
C) Gross primary productivity
D) The Redfield ratio

Question 26

If you were doing an experiment using aquatic phytoplankton and you noticed an increase in the uptake of molybdenum,what might you predict will happen to the rate of nitrogen fixation?

A) The rate of nitrogen fixation could or would be increased
B) The rate of nitrogen fixation will not change; molybdenum has no role in nitrogen fixation
C) The rate of nitrogen fixation would be decreased
D) Nitrogen fixation will be stopped

Question 27

In which ecosystem would nitrogen most likely be limiting?

A) Desert
B) Boreal forest
C) Mediterranean
D) Mountains

Question 28

Where would NPP be lowest?

A) A freshwater lake
B) An estuary
C) A subtropical ocean gyre
D) A stream

Question 29

Which of the following could be ways of expressing biomass?

A) Joules per square meter
B) Grams per square meter
C) Grams of carbon per square meter
D) None of the above

Question 30

Which of the following statements are correct regarding nitrogen fixation in subtropical ocean gyres?

A) Nitrogen fixation does occur in subtropical ocean gyres
B) Nitrogen fixation does NOT occur in subtropical ocean gyres
C) Sulfate reduces the rate of nitrogen fixation in subtropical ocean gyres
D) Phytoplankton in subtropical ocean gyres are small but highly abundant

Question 31

According to Figure 11.15b,which of the following statements is correct?

A) There are coastal marine ecosystems and estuaries along the North America Atlantic coastline and throughout the Gulf of Mexico where oxygen levels are too low to fully support animal life
B) Throughout Europe there are estuaries or coastal marine ecosystems that have been polluted by nutrients
C) There are no coastal marine ecosystems or estuaries along the Atlantic coastline of South America where oxygen levels are too low to fully support animal life
D) With the exception of Antarctica, every single continent has polluted estuaries or coastal marine ecosystems with nutrient pollution

Question 32

Most primary production does not pass through the live consumer system.Which of the following is correct relative to this statement?

A) Much primary production dies without being grazed and supports the decomposer system.
B) Not all primary productivity is assimilated to biomass because a proportion is lost to respiratory heat.
C) Plant biomass that is eaten by herbivores and herbivore biomass eaten by carnivores is not entirely incorporated into consumer biomass. What is not used is lost in feces and is used by the decomposer system.
D) All primary productivity is grazed.

Question 33

Using Figure 11.15a,which of the following are correct?

A) The majority of ecosystems where OEC is moderately to highly eutrophic are primarily found along the Pacific Coast
B) The majority of ecosystems where OEC is moderately to highly eutrophic are primarily found along the Atlantic and Gulf coasts
C) The Florida Atlantic coast region has more ecosystems with high OEC relative to the rest of the Atlantic coastline
D) The number of estuaries where OEC is moderately or severely degraded from pollution is almost twice that of those classified as low or moderately low.

Question 34

Which organisms would be the early colonists of newly dead material?

A) Bacteria
B) Fungi
C) Grazers
D) Archaea

Question 35

In general,where would net primary productivity be regulated more by the availability of nutrients?

A) In a savanna
B) In a lake
C) In a desert
D) On mountains

Question 36

According to Figure 11.22,which of the following statements are accurate?

A) The mean trophic transfer efficiency is 10.13
B) A transfer efficiency of 20% is outside of one standard deviation from the mean
C) The mean could be between 9.64 and 10.62 given the standard error
D) The distribution of transfer efficiency percentages is not normally distributed

Question 37

Which of the following are variables that determine the relative importance of energy pathways?

A) Consumption efficiencies
B) Production efficiencies
C) Stimulation efficiencies
D) Assimilation efficiencies

Question 38

Consumption efficiency of an organism is 0.25,assimilation efficiency 0.25,production efficiency 0.45,and Rauto equaled 0.01.Which of these terms would you use to calculate the trophic transfer efficiency of this organism?

A) Consumption efficiency
B) Rauto
C) Assimilation efficiency
D) Production efficiency

Question 39

According to Figure 11.24,which of the following statements are correct?

A) The median percentage of NPP consumed by herbivores in benthic microalgal beds is 40%
B) The median percentage of NPP consumed by herbivores by ecosystem is nearly always greater than 40%
C) The median percentage of NPP channeled to the DOM compartment in grasslands is nearly 100%
D) Forests and shrublands channel the lowest proportions of NPP to the DOM compartment.

Question 40

If you were interested in further understanding the relationship of abundances of elements in organisms,then you should probably do a scholarly search for which topic?

A) Organismal biology
B) Organic chemistry
C) Evolutionary biology
D) Stoichiometry

Question 41

_____________ occurs when elements are converted from organic form back to an inorganic form.

A) Immobilization
B) Mineralization
C) Decomposition
D) Salinization

Question 42

All the primary producer biomass produced is not consumed alive by herbivores.That which dies supports a community of _________?

A) Primary consumers
B) Decomposers
C) Autotrophs
D) None of the above

Question 43

The main source of nutrients such as calcium,iron,magnesium,phosphorous,and potassium in many terrestrial ecosystems is _______.

A) The Amazon River
B) The weathering of parent bedrock and soil
C) Acid rain
D) Detritivores

Question 44

______________ is a process whereby dead bodies,shed parts of bodies,or feces gradually disintegrate.

A) Immobilization
B) Decomposition
C) Mineralization
D) Desalinization

Question 45

There are a range of mutualistic interactions between detritivores and bacteria,fungi,or protozoa.These include _______?

A) Obligate and facultative mutualisms
B) Facultative and commensurate mutualisms
C) Obligate and facultative mutualisms, plus external rumens
D) External rumens and obligate mutualism

Question 46

____________ occurs when bacteria convert ammonium to nitrate.

A) The nitrogen cycle
B) Nitrification
C) Salinization
D) Assimilation

Question 47

If the ratio of nitrogen to phosphorous is slightly below 10:1 then _______.

A) It is below the Redfield ratio
B) It is at the Redfield ratio
C) It is above the Redfield ratio
D) None of the above

Question 48

,__________ occurs when an inorganic element is incorporated into an organic form.

A) Immobilization
B) Desalinization
C) Desertification
D) Mineralization

Question 49

If consumption efficiency of an organism was .25,assimilation efficiency .25 and production efficiency .45 what would the trophic transfer efficiency of this organism be??

A) 2.8%
B) 0.028%
C) 280%
D) 28%

Question 50

The most substantial pathway of loss of elements in an ecosystem is through streamflow.A system such as a stream moves phosphorous and iron mostly attached to particles,while nitrogen is mostly dissolved.Thus,a stream carries the load of nutrients _______________.

A) As mostly saturated
B) As both dissolved and particulate
C) At high concentrations at all times
D) At low concentrations at all times