Question 1

The net weight of all of the organisms living in an ecosystem is its

Accepted Answer

A)  productivity.
B)  biomass.
C)  vital force.
D)  photosynthesis minus metabolism.
E)  combined output of metabolism and photosynthesis. B

Question 2

In an ecosystem

Accepted Answer

A)  both energy and nutrients cycle.
B)  energy flows and nutrients cycle.
C)  energy cycles and nutrients flow.
D)  both energy and nutrients flow.
E)  energy is contained with nutrient cycles. B

Question 3

During the 1960s,a group of scientists in the northeastern United States conducted an experiment at Hubbard Brook,New Hampshire.A 38-acre watershed was completely deforested and the runoff (water flow)monitored for several years.It was compared to an adjacent watershed that was left untouched.The scientists collected data during those years and found

Accepted Answer

A)  no difference in the amount of runoff from the two areas.
B)  an insignificant difference in the amount of nitrogen from the two areas.
C)  a tremendous increase in the total amount of runoff from Hubbard Brook although the loss of nitrogen was fairly consistent in both areas.
D)  a tremendous increase in the amount of runoff and nitrogen release from Hubbard Brook compared to the control. D

Question 4

A ________ cycle is a cyclic path that involves both biological and chemical processes of an ecosystem.

Accepted Answer

A)  biogeochemical
B)  complete
C)  hydrological
D)  complementary

Question 5

Heterotrophs must obtain organic molecules that have been synthesized by

Accepted Answer

A)  biogeochemical cycles.
B)  bacteria.
C)  decomposers.
D)  autotrophs.

Question 6

The scarcity of which two elements limits plant growth?

Accepted Answer

A)  oxygen,nitrogen
B)  nitrogen,phosphorus
C)  oxygen,phosphorus
D)  carbon,nitrogen
E)  carbon,phosphorus

Question 7

Addition of a primary carnivore to an ecosystem can sometimes influence the whole ecosystem.This process is called

Accepted Answer

A)  ecosystem stabilization.
B)  a bottom-up effect.
C)  species turnover.
D)  disruption.
E)  a trophic cascade.

Question 8

Which of the following atmospheric gases is changing the global climate?

Accepted Answer

A)  ozone
B)  water vapor
C)  carbon dioxide
D)  hydrogen
E)  oxygen

Question 9

Vampire squid (Vampyroteuthisinfernalis)are deep-sea cephalopods with features similar to both octopus and squid.Extensive video recordings show the diet of the vampire squid consists of items like crustacean remains and fecal pellets.Which of the following terms describes the position of the vampire squid in the deep-sea trophic pyramid?

Accepted Answer

A)  herbivore
B)  primary producer
C)  primary carnivore
D)  secondary carnivore
E)  detritivore

Question 10

In a food chain with four trophic levels,what would be the energy in the top trophic level if the energy contained in the primary producer level is 40,000 kcal/m2/yr? Assume a trophic level transfer efficiency of 10%.

Accepted Answer

A)  4,000 kcal/m2/yr
B)  400 kcal/m2/yr
C)  40 kcal/m2/yr
D)  4 kcal/m2/yr
E)  0) 4 kcal/m2/yr

Question 11

In the carbon cycle,________ from the atmosphere is used in photosynthesis to synthesize carbon-containing organic molecules in a process called ________.

Accepted Answer

A)  carbon dioxide; combustion
B)  carbon dioxide; carbon fixation
C)  hydrocarbons; oxidation
D)  hydrocarbons; cellular respiration

Question 12

Which one of the following ecosystems is most likely to show an inverted biomass pyramid but a normal energy pyramid?

Accepted Answer

A)  grassland
B)  open ocean
C)  intertidal
D)  tropical forest
E)  desert

Question 13

Solar energy is the same thing as heat energy.

Accepted Answer

A) True 
 B)False

Question 14

A good average value for the amount of energy that reaches the next trophic level is about

Accepted Answer

A)  20%.
B)  10%.
C)  5%.
D)  2%.
E)  1%.

Question 15

Which of the following biogeochemical cycles contain a mineral component?

Accepted Answer

A)  phosphorus
B)  carbon
C)  nitrogen
D)  oxygen
E)  water

Question 16

A wolf that feeds on moose and elk would be classified within which trophic level?

Accepted Answer

A)  herbivore
B)  primary producer
C)  primary carnivore
D)  secondary carnivore
E)  detritivore

Question 17

Which of the following groups do not contain any species that are autotrophs?

Accepted Answer

A)  Bacteria
B)  Protista
C)  Plants
D)  Archaea
E)  Fungi

Question 18

Which of the following hypotheses support the basic principle of the species-area relationship? Check all that apply.

Accepted Answer

A)  Large areas have greater habitat diversity than small areas.
B)  Organisms are less likely to go extinct in larger areas than smaller areas.
C)  Larger areas receive more colonists than smaller areas.
D)  Smaller areas have greater concentrations of resources then larger areas.

Question 19

Which one of the following factors would NOT influence the productivity of an ocean community?

Accepted Answer

A)  the presence of nitrogen-fixing cyanobacteria
B)  the season of the year
C)  levels of autotrophs
D)  fertilizer runoff
E)  the amount of rainfall

Question 20

Even though nitrogen constitutes 78% of Earth's atmosphere,the amount available for living things nearly all comes from

Accepted Answer

A)  a few groups of nitrogen-fixing bacteria.
B)  the breakdown of minerals.
C)  a few genera of detritivores.
D)  the breakdown of dead plants.
E)  nitrogen-containing fertilizers.

Exam 56: Dynamics of Ecosystems