APES 1.8-1.11

Algae in an aquatic food chain convert solar energy into 93,000 kilocalories of plant tissue. Which of the following values best represents the amount of energy available for secondary consumers in the food chain? a. 930 kilocalories b. 9,300 kilocalories c. 93,000 kilocalories d. 930,000 kilocalories

930 kilocalories

Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers? a. Tertiary consumers are the largest organisms in an ecosystem and require the most space to survive. b. Plants can only perform photosynthesis during the day, so tertiary consumers cannot get enough energy from consuming plants. c. A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level. d. Tertiary consumers are often indicator species and are the first to be affected by environmental disturbances.

c. A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.

The table above shows the balanced chemical equations that represent three processes that are part of the nitrogen cycle. Which of the following is exemplified by the equations above? a. Approximately 10% of energy is transferred from one trophic level to the next. b. In a food web, energy flows and matter is cycled. c. Each biogeochemical cycle demonstrates the conservation of matter. d. The major reserve for nitrogen is in the atmosphere.

c. Each biogeochemical cycle demonstrates the conservation of matter.

Scientists calculated the net primary productivity at two different forest sites. Both forests have the same gross primary productivity. Forest A has a net primary productivity of 1,650kcal/m2/year, and forest B has a net primary productivity of 1,110kcal/m2/year. Which of the following statements is best supported by the data? a. Forest A has a higher rate of decomposition by bacteria than forest B. b. Forest A has more biodiversity than forest B. c. Forest A producers have lower rates of cellular respiration than forest B producers. d. Forest A producers have more biomass than forest B producers.

c. Forest A producers have lower rates of cellular respiration than forest B producers.

Based on the diagram, which group of organisms would be considered herbivores? a. Snakes b. Mice c. Grasshoppers d. Grasses

c. Grasshoppers

Which of the following best describes the net primary productivity of an ecosystem? a. Net primary productivity is the amount of energy captured by producers through photosynthesis over time. b. Net primary productivity is the amount of energy lost by producers through respiration over time. c. Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem. d. Net primary productivity is the amount of energy lost through respiration by producers added to the gross primary productivity of an ecosystem.

c. Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem.

Which of the following best explains why decomposers in soils and water are important to ecosystems? a. They remove heavy metals b. They store carbon dioxide c. They recycle nutrients d. They neutralize acid deposition e. they produce more oxygen than they consume

c. They recycle nutrients

For a primary producer, the main function of photosynthesis is to manufacture a. oxygen b. carbon dioxide c. glucose d. proteins e. water

c. glucose

Open oceans produce the largest share of Earth's biomass because the net primary productivity (NPP) of the oceans is a. high and thus can support a high proportion of producers b. high as a result of the high concentration of nutrients in the open oceans c. low, but the large expanse of the oceans supports enormous numbers of producers such as phytoplankton d. low, but the individual producers found there are huge in size e. low, but still higher than that of other ecosystems of the world

c. low, but the large expanse of the oceans supports enormous numbers of producers such as phytoplankton

The net annual primary productivity of a particular wetland ecosystem is found to be 8,000 kcal/m2 per year. If respiration by the aquatic producers is 12,000 kcal/m2 per year, what is the gross annual primary productivity for this ecosystem, in kcal/m2 per year? a. 4,000 b. 8,000 c. 12,000 d. 20,000 e. 96,000

d. 20,000

Which of the following categories of organisms, which are required for the cycling of matter in an ecosystem, is missing from the table? a. Producers b. Primary consumers c. Secondary consumders d. Decomposers

d. Decomposers

Which of the following best describes gross primary productivity in an ecosystem? a. Gross primary productivity is the total amount of energy captured by producers plus the energy used by consumers over time. b. Gross primary productivity is the total amount of energy captured by producers minus the energy that producers respire over time. c. Gross primary productivity is the total amount of energy lost as heat during energy transfer between trophic levels. d. Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.

d. Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.

The terrestrial biomes shown in the diagram above vary in net primary productivity. The explanation for the variation includes which of the following? I. Temperature II. Precipitation III. Longitude a. I only b. II only c. III only d. I and II only e. II and III only

d. I and II only

The maximum efficiency possible in an energy-conversion process that is not limited by the second law of thermodynamics a. 100% b. 95% c. 30% d. 15% e. 1%

a. 100%

Based on the data in the table, if the number of snakes were to suddenly decrease, which of the following changes would most likely occur in the food web of this ecosystem? a. increase in number of shrews | decrease in number of hawks b. increase in number of hawks | decrease in number of shrews c. increase in number of grasshoppers | decrease in number of plants d. increase in number of spiders | decrease in number of plants

a. increase in number of shrews | decrease in number of hawks

In a given ecosystem, producers convert solar energy into 15,000kcal of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers? a. 1.5 kcal b. 150 kcal c. 1,500 kcal d. 13,500 kcal

b. 150 kcal

Algae in an aquatic food chain convert solar energy into 93,000 kilocalories of plant tissue. Which of the following values best represents the amount of energy available for primary consumers in the food chain? a. 930 kilocalories b. 9,300 kilocalories c. 93,000 kilocalories d. 930,000 kilocalories

b. 9,300 kilocalories

Of the following organisms, which occupies the lowest trophic level? a. Spider b. Deer c. Lion d. Hawk e. Snake

b. Deer

Losses of usable energy between successive trophic levels in an ecosystem are best accounted for by which of the following? a. The first law of thermodynamics b. The second law of thermodynamics c. The law of conservation of matter d. The process of ecological succession e. Limiting factors in the ecosystem

b. The second law of thermodynamics

The ultimate source of energy for terrestrial ecosystem is a. nutrients in soil b. nutrients in vegetation c. primary consumers d. producers e. the sun

e. the sun

An energy transformation occurs and results in increased disorder. a. Heat flow b. Kinetic energy c. Potential energy d. First law of thermodynamics e. Second law of thermodynamics

e. Second law of thermodynamics

Which of the following best describes the movement of energy in an ecosystem? a. Energy is constantly recycled by decomposers for use by producers. b. Energy is harnessed by producers, and available energy decreases with each trophic level transfer. c. Energy is absorbed by plants through water and soil and then moves up the food chain through consumers. d. Energy is magnified as it moves up the trophic levels, and tertiary consumers store the most energy in a food web.

b. Energy is harnessed by producers, and available energy decreases with each trophic level transfer.

Based on the data in the table, which of the following pairs of organisms has two ecological relationships, both competition and predation? a. Spiders and shrews b. Hawks and snakes c. Spiders and snakes d. Spiders and grasshoppers

b. Hawks and snakes

Which of the following best describes the first law of thermodynamics? a. Energy always changes from a more useful, more concentrated form to a less useful, less concentrated form. b. In a closed system of constant mass, the energy involved in any physical or chemical change is neither created nor destroyed, but merely changed from one form to another. c. Heat always flows from a hot body to a cold body. d. Entropy of a system increases as the state of disorganization in the system increases. e. In a reversible process, the entropy of the system is constant, whereas in an irreversible process, the entropy of the system increases.

b. In a closed system of constant mass, the energy involved in any physical or chemical change is neither created nor destroyed, but merely changed from one form to another.

Of the following ecosystems, which has the lowest net primary productivity, measured as kilocalories of energy produced per square meter per year? a. Taiga b. Open ocean c. Temperate grassland d. Estuary e. Agricultural land

b. Open ocean

Approximate efficiency of the conversion of light energy to chemical energy in photosynthesis a. 100% b. 95% c. 30% d. 15% e. 1%

e. 1%