Ch 54 Self Quiz: Ecosystems

1) If the flow of energy in an Arctic ecosystem goes through a simple food chain from seaweeds to fish to seals to polar bears, then which of the following is TRUE?
A) The carnivores can provide more food for the Eskimos than the herbivores can.
B) Polar bears can provide more food for Eskimos than seals can.
C) Polar bear meat probably contains the highest concentrations of fat-soluble toxins.
D) The total energy content of the seaweeds is lower than that of the seals.
E) Seals are more numerous than fish.

2) The high levels of pesticides found in birds of prey is an example of
A) predation.
B) biological magnification.
C) the Gaia hypothesis.
D) chemical cycling through an ecosystem.
E) eutrophication.

3) The producers in ecosystems include which of the following?
I. photosynthetic protists
II. cyanobacteria
III. plants

A) II only
B) I only
C) I and III only
D) III only
E) I, II, and III

4) All of the following statements about energy flow are correct EXCEPT:
A) Only about one thousandth of the chemical energy fixed by photosynthesis actually reaches a tertiary-level consumer.
B) Secondary productivity declines with each trophic level.
C) Only net primary productivity is available to consumers.
D) Eating meat is probably the most efficient way of acquiring the energy of photosynthetic productivity.
E) About 90% of the energy at one trophic level does not appear at the next.

5) Which of the following statements is CORRECT about biogeochemical cycling?
A) The phosphorus cycle involves the rapid recycling of atmospheric phosphorus.
B) The phosphorus cycle is a sedimentary cycle that involves the weathering of rocks.
C) The carbon cycle is a localized cycle that primarily reflects the burning of fossil fuels.
D) The equation 6 CO2 + 6 H2O rightarrow C6H12O6 + 6 O2 accounts for the tremendous CO2 buffering capabilities of the ocean.
E) The carbon cycle has maintained the atmospheric concentration of CO2 constant for the past million years.

6) In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are
A) denitrifying bacteria.
B) nitrogen-fixing bacteria.
C) Rhizobium bacteria.
D) methanogenic protozoans.
E) nitrifying bacteria.

The following questions refer to the organisms in a grassland ecosystem listed below. Each term may be used once, more than once, or not at all.

A. hawks
B. snakes
C. shrews
D. grasshoppers
E. grass

7) an autotroph

8) an herbivore

9) smallest biomass

10) incorporates greatest amount of energy

11) probably the highest internal concentration of toxic pollutants

The following questions refer to the terms below. Each term may be used once, more than once, or not at all.

A. Gaia hypothesis
B. turnover
C. biomagnification
D. greenhouse effect
E. cultural eutrophication

12) caused excessive levels of DDT in fish-eating birds

13) Many homeowners mow their lawns during the summer and collect the clippings, which are then hauled to the local landfill each week. Which of the following would comprise an alternative that would cause the least disturbance to local ecosystems?
A) Dig up the lawn and cover the yard with asphalt.
B) Either collect the clippings and add them to a compost pile, or don't collect the clippings and let them decompose in the lawn.
C) Collect the clippings and burn them.
D) Collect the clippings and wash them into the nearest storm sewer that feeds into the local lake.
E) Don't mow the lawn-have a goat graze on it and put the goat's feces into the landfill.

14) Production, consumption, and decomposition are important ecosystem processes. Organisms in which of the following taxa perform decomposition?
A) cyanobacteria
B) vertebrates
C) invertebrates
D) All of the above are correct.
E) A and C only are correct.

15) Some aquatic ecosystems can have inverted biomass pyramids because
A) phytoplankton have a relatively short turnover time.
B) consumption by phytoplankton by zooplankton is so rapid that the standing crop of phytoplankton remains relatively low.
C) Both A and B are correct.
D) None of the above is correct because inverted biomass pyramids cannot exist in any type of ecosystem.