1) How are matter and energy used in ecosystems?
A) Matter is cycled through ecosystems; energy is not.
2) A cow's herbivorous diet indicates that it is a(n)
A) primary consumer.
3) To recycle nutrients, the minimum an ecosystem must have is
B) producers and decomposers.
8) What is the most important role of photosynthetic organisms in an ecosystem?
A) converting inorganic compounds into organic compounds
9) Ecosystems are
B) processors of matter and transformers of energy.
If the Sun were to suddenly stop providing energy to Earth, most ecosystems would vanish.
Which of the following ecosystems would likely survive the longest after this hypothetical
C) benthic ocean
12) Which of the following is true of detrivores?
They convert organic materials from all trophic levels to inorganic compounds usable by
Subtraction of which of the following will convert gross primary productivity into net
C) the energy used by autotrophs in respiration
Which of these ecosystems accounts for the largest amount of Earth's net primary
D) open ocean
18) Which of these ecosystems has the highest net primary productivity per square meter?
D) tropical rain forest
How is it that the open ocean produces the highest net primary productivity of Earth's
ecosystems, yet net primary productivity per square meter is relatively low?
C) Oceans have the greatest total area.
21) Aquatic primary productivity is most limited by which of the following?
A) light and nutrient availability
22) Aquatic ecosystems are least likely to be limited by which of the following nutrients?
As big as it is, the ocean is nutrient-limited. If you wanted to investigate this, one reasonable
avenue would be to
experimentally enrich some areas of the ocean and compare their productivity to that of
A porcupine eats 3,000 J of plant material. 1,600 J is indigestible and is eliminated as feces.
1,300 J are used in cellular respiration. What is the approximate production efficiency of this
Which of the following lists of organisms is ranked in correct order from lowest to highest
percent in production efficiency?
A) mammals, fish, insects
30) Trophic efficiency is
B) the percentage of production transferred from one trophic level to the next.
In general, the total biomass in a terrestrial ecosystem will be greatest for which trophic
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
B) at each step, energy is lost from the system as a result of keeping the organisms alive.
Which of the following is primarily responsible for limiting the number of trophic levels in
E) Energy transfer between tropic levels is in almost all cases less than 20% efficient.
A secondary consumer, such as a fox, receives what percent of the energy fixed by primary
producers in a typical field ecosystem
Which statement best describes what ultimately happens to the chemical energy that is not
converted to new biomass in the process of energy transfer between trophic levels in an
D) It is dissipated into space as heat in accordance with the second law of thermodynamics.
40) Nitrogen is available to plants only in the form of
E) nitrate ions in the soil.
42) How does phosphorus normally enter ecosystems?
C) rock weathering
48) Human-induced modifications of the nitrogen cycle can result in
A) eutrophication of adjacent wetlands.
50) The high levels of pesticides found in birds of prey is an example of
C) biological magnification.
57) Which of the following is a tertiary consumer?
Which of the following probably contains the highest concentration of toxic pollutants
Which of the following causes an increase in the intensity of UV radiation reaching the
A) depletion of atmospheric ozone
) Which of the following describes carbon dioxide, methane, and water vapor re-reflecting
infrared radiation back toward Earth?
D) greenhouse effect
62) Which of the following is caused by excessive nutrient runoff into lakes?
Which of the following causes excessively high levels of toxic chemicals in fish-eating
C) biological magnification
64) Agricultural lands frequently require nutritional supplementation because
) the nutrients that enter the plants are not returned to the soil on lands where they are
Burning fossil fuels releases oxides of sulfur and nitrogen. Ultimately, these are probably
A) the death of fish in Norwegian lakes.
B) rain with a pH as low as 3.0.
C) calcium deficiency in soils.
D) direct damage to plants by leaching nutrients from the leaves.
E) A, B, C, and D are all correct.
1) Which of the following organisms is incorrectly paired with its trophic level?
C) zooplankton-primary producer
2) Which of these ecosystems has the lowest net primary production per square meter?
B) an open ocean
3) Nitrifying bacteria participate in the nitrogen cycle mainly by
D) converting ammonium to nitrate, which plants absorb.
Which of the following has the greatest effect on the rate of chemical cycling in an
C) the rate of decomposition in the ecosystem
The Hubbard Brook watershed deforestation experiment yielded all of the following results
E) calcium levels remained high in the soil of deforested areas.
6) Which of the following is a consequence of biological magnification?
Toxic chemicals in the environment pose greater risk to top-level predators than to primary
The main cause of the increase in the amount of CO2 in Earth's atmosphere over the past 150
D) the burning of larger amounts of wood and fossil fuels.