Chapter 55 Practice Multiple Choice
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Which of the following terms encompasses all of the others?
a. heterotrophs
b. herbivores
c. carnivores
d. primary consumers
e. secondary consumers
____
2. Many homeowners mow their lawns during the summer and collect the clippings, which are then
hauled to the local landfill. Which of the following actions would most benefit the local ecosystem?
a. Allow sheep to graze the lawn and then collect the sheep's feces to be delivered to
the landfill.
b. Collect the lawn clippings and burn them.
c. Either collect the clippings and add them to a compost pile, or don't collect the
clippings and let them decompose into the lawn.
d. Collect the clippings and wash them into the nearest storm sewer that feeds into
the local lake.
e. Dig up the lawn and cover the yard with asphalt.
____
3. What is the most important role of photosynthetic organisms in an ecosystem?
a. converting inorganic compounds into organic compounds
b. absorbing solar radiation
c. producing organic detritus for decomposers
d. dissipating heat
e. recycling energy from other tropic levels
____
4. Which of the following is an example of an ecosystem?
a. All of the brook trout in a 500 hectare2 river drainage system.
b. The plants, animals, and decomposers that inhabit an alpine meadow.
c. A pond and all of the plant and animal species that live in it.
d. The intricate interactions of the various plant and animal species on a savanna
during a drought.
e. Interactions between all of the organisms and their physical environment in a
tropical rain forest.
____
5. Which of the following is true of detrivores?
a. They recycle chemical elements directly back to primary consumers.
b. They synthesize organic molecules that are used by primary producers.
c. They convert organic materials from all trophic levels to inorganic compounds
usable by primary producers.
d. They secrete enzymes that convert the organic molecules of detritus into CO2 and
H 2 O.
e. Some species are autotrophic, while others are heterotrophic.
____
6. The difference between net and gross primary productivity would likely be greatest for
a. phytoplankton in the ocean.
b. corn plants in a farmer's field.
c. prairie grasses.
d. an oak tree in a forest.
e. sphagnum moss in a bog.
____
7. Which of these ecosystems accounts for the largest amount of Earth's net primary productivity?
a. tundra
b. savanna
c. salt marsh
d. open ocean
e. tropical rain forest
____
8. Aquatic ecosystems are least likely to be limited by which of the following nutrients?
a. nitrogen
b. carbon
c. phosphorus
d. iron
e. zinc
____
9. How is it that satellites can detect differences in primary productivity on Earth?
a. Photosynthesizers absorb more visible light in the 350—750 wavelengths.
b. Satellite instruments can detect reflectance patterns of the photosynthesizers of
different ecosystems.
c. Sensitive satellite instruments can measure the amount of NADPH produced in the
summative light reactions of different ecosystems.
d. By comparing the wavelengths of light captured and reflected by
photosynthesizers to the amount of light reaching different ecosystems.
e. By measuring the amount of water vapor emitted by transpiring photosynthesizers.
____ 10. Which of the following lists of organisms is ranked in correct order from lowest to highest percent in
production efficiency?
a. mammals, fish, insects
b. insects, fish, mammals
c. fish, insects, mammals
d. insects, mammals, fish
e. mammals, insects, fish
____ 11. If you wanted to convert excess grain into the greatest amount of animal biomass, to which animal
would you feed the grain?
a. chickens
b. mice
c. cattle
d. carp (a type of fish)
e. mealworms (larval insects)
____ 12. In general, the total biomass in a terrestrial ecosystem will be greatest for which trophic level?
a.
b.
c.
d.
e.
producers
herbivores
primary consumers
tertiary consumers
secondary consumers
Refer to Figure 55.1, a diagram of a food web, for the following questions. (Arrows represent energy
flow and letters represent species.)
Figure 55.1
____ 13. For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially the same-
they have a broad base and a narrow top. The primary reason for this pattern is that
a. secondary consumers and top carnivores require less energy than producers.
b. at each step, energy is lost from the system as a result of keeping the organisms
alive.
c. as matter passes through ecosystems, some of it is lost to the environment.
d. biomagnification of toxic materials limits the secondary consumers and top
carnivores.
e. top carnivores and secondary consumers have a more general diet than primary
producers.
____ 14. If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving
humans, starts from seaweeds to fish to seals to polar bears, then which of the following could be
true?
a. Polar bears can provide more food for humans than seals can.
b. The total biomass of the seaweeds is lower than that of the seals.
c. Seal meat probably contains the highest concentrations of fat-soluble toxins.
d. Seal populations are larger than fish populations.
e. The seaweed can potentially provide more food for humans than the seal meat can.
____ 15. Nitrogen is available to plants only in the form of
a. N2 in the atmosphere.
b. nitrite ions in the soil.
c. uric acid from animal excretions.
d. amino acids from decomposing plant and animal proteins.
e. nitrate ions in the soil.
____ 16. How does phosphorus normally enter ecosystems?
a. cellular respiration
b. photosynthesis
c. rock weathering
d. geological uplifting (subduction and vulcanism)
e. atmospheric phosphorous dust
____ 17. In terms of nutrient cycling, why does timber harvesting in a temperate forest cause less ecological
devastation than timber harvesting in tropical rain forests?
a. Trees are generally smaller in temperate forests, so fewer nutrients will be
removed from the temperate forest ecosystem during a harvest.
b. Temperate forest tree species require fewer nutrients to survive than their tropical
counterpart species, so a harvest removes fewer nutrients from the temperate
ecosystem.
c. The warmer temperatures in the tropics influence rain forest species to assimilate
nutrients more slowly, so tropical reforestation is much slower than temperate
reforestation.
d. There are far fewer decomposers in tropical rain forests so turning organic matter
into usable nutrients is a slower process than in temperate forest ecosystems.
e. Typical harvests remove up to 75% of the nutrients in the woody trunks of tropical
rain forest trees, leaving nutrient-impoverished soils behind.
____ 18. Which of the following describes carbon dioxide, methane, and water vapor re-reflecting infrared
radiation back toward Earth?
a. depletion of atmospheric ozone
b. turnover
c. biological magnification
d. greenhouse effect
e. eutrophication
____ 19. Which of the following causes excessively high levels of toxic chemicals in fish-eating birds?
a. depletion of atmospheric ozone
b. turnover
c. biological magnification
d. greenhouse effect
e. eutrophication
____ 20. Agricultural lands frequently require nutritional supplementation because
a. nitrogen-fixing bacteria and detrivores do not cycle nutrients as effectively as they
do on wild lands.
b. the nutrients that enter the plants are not returned to the soil on lands where they
are harvested.
c. the prairies that comprise good agricultural land tend to be nutrient-poor.
d. grains raised for feed must be fortified, and thus require additional nutrients.
e. cultivation of agricultural lands inhibits the decomposition of organic matter.
____ 21. You have a friend who is wary of environmentalists' claims that global warming could lead to major
biological change on Earth. Which of the following statements can you truthfully make in response
to your friend's suspicions?
a. We know that atmospheric carbon dioxide has increased in the last 150 years.
b. Through measurements and observations, we know that carbon dioxide levels and
temperature fluctuations were directly correlated even in prehistoric times.
c. Global warming could have significant effects on United States agriculture.
d. Sea levels will likely rise, displacing as much as 50% of the world's human
population.
e. A, B, C, and D are all correct
Use the incomplete diagram below, illustrating some of the steps involved in eutrophication to
answer the following questions.
Figure 55.3
____ 22. What would be a likely entry for box B?
a. decomposer population carries on cellular respiration and uses up oxygen
b. plants no longer producing oxygen
c. warm water holding less oxygen than cold water
d. fish that cannot acclimate to low oxygen levels
e. carbon dioxide building up from cellular respiration by decomposers
____ 23. Aquatic ecosystems that are most readily damaged by acid are those that lack an important buffer
that dissolves into the runoff after a precipitation event. What is this buffer?
a. calcium
b. carbonic acid
c. nitrate
d. bicarbonate
e. sulfate
____ 24. Nitrifying bacteria participate in the nitrogen cycle mainly by
a.
b.
c.
d.
e.
converting nitrogen gas to ammonia.
releasing ammonium from organic compounds, thus returning it to the soil.
converting ammonia to nitrogen gas, which returns to the atmosphere.
converting ammonium to nitrate, which plants absorb.
incorporating nitrogen into amino acids and organic compounds.
____ 25. The Hubbard Brook watershed deforestation experiment yielded all of the following results except
that
a. most minerals were recycled within a forest ecosystem.
b. the flow of minerals out of a natural watershed was offset by minerals flowing in.
c. deforestation increased water runoff.
d. the nitrate concentration in waters draining the deforested area became
dangerously high.
e. calcium levels remained high in the soil of deforested areas.
Chapter 55 Practice Multiple Choice
Answer Section
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Concept 55.1
Concept 55.1
Concept 55.1
Concept 55.1
Concept 55.1
Concept 55.2
Concept 55.2
Concept 55.2
Concept 55.2
Concept 55.2
Concept 55.3
Concept 55.3
Concept 55.3
Concept 55.3
Concept 55.4
Concept 55.4
Concept 55.4
Concept 55.5
Concept 55.5
Concept 55.5
Concept 55.5
Concept 55.5
Concept 55.5
Self-Quiz Questions
Self-Quiz Questions