Energy Flow and the 10% Rule - AP Environmental Science
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Calculate energy efficiency if 50 J is transferred from 500 J.
Calculate energy efficiency if 50 J is transferred from 500 J.
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10%. $\frac{50}{500} \times 100 = 10$% efficiency.
10%. $\frac{50}{500} \times 100 = 10$% efficiency.
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Which type of organism occupies multiple trophic levels?
Which type of organism occupies multiple trophic levels?
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Omnivores. They consume both plants and animals.
Omnivores. They consume both plants and animals.
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What is the typical shape of an energy pyramid?
What is the typical shape of an energy pyramid?
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Pyramid shape. Energy decreases at each ascending level.
Pyramid shape. Energy decreases at each ascending level.
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What term describes the energy trapped by producers from sunlight?
What term describes the energy trapped by producers from sunlight?
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Gross primary productivity. Total energy captured through photosynthesis.
Gross primary productivity. Total energy captured through photosynthesis.
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Identify the trophic level of apex predators.
Identify the trophic level of apex predators.
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Top trophic level. Highest consumers in the food chain.
Top trophic level. Highest consumers in the food chain.
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Identify the form of energy transfer that is not 100% efficient.
Identify the form of energy transfer that is not 100% efficient.
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Trophic transfer. Energy decreases between feeding levels.
Trophic transfer. Energy decreases between feeding levels.
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What is the role of decomposers in energy flow?
What is the role of decomposers in energy flow?
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Decomposers break down dead matter and recycle nutrients. They return energy to the ecosystem base.
Decomposers break down dead matter and recycle nutrients. They return energy to the ecosystem base.
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Which type of organism occupies multiple trophic levels?
Which type of organism occupies multiple trophic levels?
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Omnivores. They consume both plants and animals.
Omnivores. They consume both plants and animals.
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What type of pyramid shows the number of organisms in each trophic level?
What type of pyramid shows the number of organisms in each trophic level?
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Pyramid of numbers. Shows organism abundance at each level.
Pyramid of numbers. Shows organism abundance at each level.
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What term describes the 90% of energy not transferred to the next level?
What term describes the 90% of energy not transferred to the next level?
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Energy loss. Energy dissipated and unavailable for transfer.
Energy loss. Energy dissipated and unavailable for transfer.
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Calculate the energy available at the fourth trophic level if 1000 J starts at the first.
Calculate the energy available at the fourth trophic level if 1000 J starts at the first.
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1 J. Three 10% transfers: $1000 \times 0.1^3 = 1$ J.
1 J. Three 10% transfers: $1000 \times 0.1^3 = 1$ J.
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State the formula for energy transfer efficiency between trophic levels.
State the formula for energy transfer efficiency between trophic levels.
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Efficiency = $\frac{\text{Energy to next level}}{\text{Energy from previous level}} \times 100$. Calculates percentage of energy passing between levels.
Efficiency = $\frac{\text{Energy to next level}}{\text{Energy from previous level}} \times 100$. Calculates percentage of energy passing between levels.
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What is the relationship between biomass and energy in ecosystems?
What is the relationship between biomass and energy in ecosystems?
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Biomass decreases as energy decreases up the trophic levels. Less biomass supports higher trophic levels.
Biomass decreases as energy decreases up the trophic levels. Less biomass supports higher trophic levels.
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Identify the primary source of energy in most ecosystems.
Identify the primary source of energy in most ecosystems.
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The Sun. Solar radiation drives photosynthesis in producers.
The Sun. Solar radiation drives photosynthesis in producers.
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Which trophic level do herbivores belong to?
Which trophic level do herbivores belong to?
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Second trophic level. Primary consumers feed directly on producers.
Second trophic level. Primary consumers feed directly on producers.
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Identify the unit commonly used to measure energy in ecosystems.
Identify the unit commonly used to measure energy in ecosystems.
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Joules (J). Standard unit for measuring energy transfer.
Joules (J). Standard unit for measuring energy transfer.
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Determine the energy at the third trophic level if 1000 J is at the first.
Determine the energy at the third trophic level if 1000 J is at the first.
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10 J. Two 10% transfers: $1000 \times 0.1 \times 0.1 = 10$ J.
10 J. Two 10% transfers: $1000 \times 0.1 \times 0.1 = 10$ J.
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Identify the term for organisms that consume producers.
Identify the term for organisms that consume producers.
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Primary consumers. Herbivores that eat producers directly.
Primary consumers. Herbivores that eat producers directly.
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What is the 10% rule in energy transfer?
What is the 10% rule in energy transfer?
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Only 10% of energy is transferred to the next trophic level. 90% is lost as heat during metabolic processes.
Only 10% of energy is transferred to the next trophic level. 90% is lost as heat during metabolic processes.
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State the energy transfer efficiency if 10 J is gained from 100 J.
State the energy transfer efficiency if 10 J is gained from 100 J.
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10%. $\frac{10}{100} \times 100 = 10$% efficiency.
10%. $\frac{10}{100} \times 100 = 10$% efficiency.
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What trophic level are primary producers located at?
What trophic level are primary producers located at?
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First trophic level. Producers form the base of energy pyramids.
First trophic level. Producers form the base of energy pyramids.
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Which law of thermodynamics explains energy loss as heat?
Which law of thermodynamics explains energy loss as heat?
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Second law of thermodynamics. States energy becomes less useful over time.
Second law of thermodynamics. States energy becomes less useful over time.
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What is the effect of energy loss on ecosystem structure?
What is the effect of energy loss on ecosystem structure?
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Fewer organisms at higher trophic levels. Energy constraints limit higher level populations.
Fewer organisms at higher trophic levels. Energy constraints limit higher level populations.
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Choose the correct term: Energy pyramids show energy flow in a(n) ______.
Choose the correct term: Energy pyramids show energy flow in a(n) ______.
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ecosystem. Energy flows through interconnected communities.
ecosystem. Energy flows through interconnected communities.
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Identify the type of organism at the base of an energy pyramid.
Identify the type of organism at the base of an energy pyramid.
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Producers. Autotrophs capture solar energy at the base.
Producers. Autotrophs capture solar energy at the base.
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Find total energy loss if 1000 J is at first level, reaching 10 J at third.
Find total energy loss if 1000 J is at first level, reaching 10 J at third.
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990 J. Total lost: $1000 - 10 = 990$ J.
990 J. Total lost: $1000 - 10 = 990$ J.
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Identify the process by which producers capture solar energy.
Identify the process by which producers capture solar energy.
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Photosynthesis. Converts light energy into chemical energy.
Photosynthesis. Converts light energy into chemical energy.
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What is the energy efficiency of a trophic level if 25 J is transferred from 250 J?
What is the energy efficiency of a trophic level if 25 J is transferred from 250 J?
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10%. $\frac{25}{250} \times 100 = 10$% efficiency.
10%. $\frac{25}{250} \times 100 = 10$% efficiency.
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Which organisms decompose organic material and return nutrients to soil?
Which organisms decompose organic material and return nutrients to soil?
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Decomposers. Bacteria and fungi recycle nutrients.
Decomposers. Bacteria and fungi recycle nutrients.
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What is the energy available to herbivores from plants called?
What is the energy available to herbivores from plants called?
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Net primary productivity. Energy remaining after plant respiration.
Net primary productivity. Energy remaining after plant respiration.
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