AP Environmental Science Flashcards: Energy Flow And The 10 Rule

What this deck covers

This deck focuses on Energy Flow And The 10 Rule, giving you a quick way to review the definitions, rules, and examples that matter most for AP Environmental Science.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: Calculate the energy available at the fourth trophic level if 1000 J starts at the first.

Answer: 1 J. Three 10% transfers: $1000 \times 0.1^3 = 1$ J.

Flashcard 2: Which type of organism occupies multiple trophic levels?

Answer: Omnivores. They consume both plants and animals.

Flashcard 3: State the main reason for energy loss between trophic levels.

Answer: Heat loss due to metabolic processes. Cellular respiration releases energy as heat.

Flashcard 4: What type of pyramid shows the number of organisms in each trophic level?

Answer: Pyramid of numbers. Shows organism abundance at each level.

Flashcard 5: What percentage of energy do secondary consumers receive from producers?

Answer: 1%. Two 10% transfers from original producers.

Flashcard 6: What occurs to energy not transferred to the next trophic level?

Answer: It is lost as heat or used in metabolism. Energy dissipates through cellular respiration.

Flashcard 7: Determine the energy at the third trophic level if 1000 J is at the first.

Answer: 10 J. Two 10% transfers: $1000 \times 0.1 \times 0.1 = 10$ J.

Flashcard 8: What is the energy available to herbivores from plants called?

Answer: Net primary productivity. Energy remaining after plant respiration.

Flashcard 9: What is the energy efficiency of a trophic level if 25 J is transferred from 250 J?

Answer: 10%. $\frac{25}{250} \times 100 = 10$% efficiency.

Flashcard 10: Calculate the energy loss if 5000 J is reduced to 500 J in the next level.

Answer: 4500 J. Energy lost: $5000 - 500 = 4500$ J.

Flashcard 11: Identify the term for energy not used in growth or reproduction.

Answer: Respired energy. Energy used for maintenance, not biomass.

Flashcard 12: What type of pyramid shows the number of organisms in each trophic level?

Answer: Pyramid of numbers. Shows organism abundance at each level.

Flashcard 13: Identify the unit commonly used to measure energy in ecosystems.

Answer: Joules (J). Standard unit for measuring energy transfer.

Flashcard 14: Choose the correct term: Energy pyramids show energy flow in a(n)  .

Answer: ecosystem. Energy flows through interconnected communities.

Flashcard 15: Find the energy transferred to the next level if 5000 J is consumed.

Answer: 500 J. Apply the 10% rule: $5000 \times 0.1 = 500$ J.

Flashcard 16: Identify the term for organisms that consume producers.

Answer: Primary consumers. Herbivores that eat producers directly.

Flashcard 17: Which type of organism occupies multiple trophic levels?

Answer: Omnivores. They consume both plants and animals.

Flashcard 18: Which trophic level do herbivores belong to?

Answer: Second trophic level. Primary consumers feed directly on producers.

Flashcard 19: What is the main cause of energy loss in food chains?

Answer: Metabolic heat. Thermal energy lost during cellular processes.

Flashcard 20: Which organisms decompose organic material and return nutrients to soil?

Answer: Decomposers. Bacteria and fungi recycle nutrients.

Flashcard 21: Identify the type of organism at the base of an energy pyramid.

Answer: Producers. Autotrophs capture solar energy at the base.

Flashcard 22: What percentage of energy is typically lost as heat?

Answer: 90%. Most energy converts to heat during metabolism.

Flashcard 23: Which law of thermodynamics explains energy loss as heat?

Answer: Second law of thermodynamics. States energy becomes less useful over time.

Flashcard 24: What term describes the energy trapped by producers from sunlight?

Answer: Gross primary productivity. Total energy captured through photosynthesis.

Flashcard 25: State the main reason for energy loss between trophic levels.

Answer: Heat loss due to metabolic processes. Cellular respiration releases energy as heat.

Flashcard 26: What percentage of energy do secondary consumers receive from producers?

Answer: 1%. Two 10% transfers from original producers.

Flashcard 27: Identify the primary source of energy in most ecosystems.

Answer: The Sun. Solar radiation drives photosynthesis in producers.

Flashcard 28: What term describes the 90% of energy not transferred to the next level?

Answer: Energy loss. Energy dissipated and unavailable for transfer.

Flashcard 29: State the energy transfer efficiency if 10 J is gained from 100 J.

Answer: 10%. $\frac{10}{100} \times 100 = 10$% efficiency.

Flashcard 30: Identify the trophic level of apex predators.

Answer: Top trophic level. Highest consumers in the food chain.

Flashcard 31: What occurs to energy not transferred to the next trophic level?

Answer: It is lost as heat or used in metabolism. Energy dissipates through cellular respiration.

Flashcard 32: What trophic level are primary producers located at?

Answer: First trophic level. Producers form the base of energy pyramids.

Flashcard 33: What is the main cause of energy loss in food chains?

Answer: Metabolic heat. Thermal energy lost during cellular processes.

Flashcard 34: What is the relationship between biomass and energy in ecosystems?

Answer: Biomass decreases as energy decreases up the trophic levels. Less biomass supports higher trophic levels.

Flashcard 35: Identify the trophic level of apex predators.

Answer: Top trophic level. Highest consumers in the food chain.

Flashcard 36: What percentage of energy is typically lost as heat?

Answer: 90%. Most energy converts to heat during metabolism.

Flashcard 37: Determine the energy at the third trophic level if 1000 J is at the first.

Answer: 10 J. Two 10% transfers: $1000 \times 0.1 \times 0.1 = 10$ J.

Flashcard 38: What is the effect of energy loss on ecosystem structure?

Answer: Fewer organisms at higher trophic levels. Energy constraints limit higher level populations.

Flashcard 39: Which organisms decompose organic material and return nutrients to soil?

Answer: Decomposers. Bacteria and fungi recycle nutrients.

Flashcard 40: Choose the correct term: Energy pyramids show energy flow in a(n)  .

Answer: ecosystem. Energy flows through interconnected communities.

Flashcard 41: Calculate energy transfer if 2000 J is available and 10% is passed on.

Answer: 200 J. 10% of 2000 J equals 200 J transferred.

Flashcard 42: Identify the process by which producers capture solar energy.

Answer: Photosynthesis. Converts light energy into chemical energy.

Flashcard 43: State the formula for energy transfer efficiency between trophic levels.

Answer: Efficiency = $\frac{\text{Energy to next level}}{\text{Energy from previous level}} \times 100$. Calculates percentage of energy passing between levels.

Flashcard 44: Which trophic level do herbivores belong to?

Answer: Second trophic level. Primary consumers feed directly on producers.

Flashcard 45: State the formula for energy transfer efficiency between trophic levels.

Answer: Efficiency = $\frac{\text{Energy to next level}}{\text{Energy from previous level}} \times 100$. Calculates percentage of energy passing between levels.

Flashcard 46: Identify the term for energy not used in growth or reproduction.

Answer: Respired energy. Energy used for maintenance, not biomass.

Flashcard 47: Identify the form of energy transfer that is not 100% efficient.

Answer: Trophic transfer. Energy decreases between feeding levels.

Flashcard 48: State the energy transfer efficiency if 10 J is gained from 100 J.

Answer: 10%. $\frac{10}{100} \times 100 = 10$% efficiency.

Flashcard 49: Identify the form of energy transfer that is not 100% efficient.

Answer: Trophic transfer. Energy decreases between feeding levels.

Flashcard 50: Identify the process by which energy is lost as heat in organisms.

Answer: Respiration. Cellular process that releases thermal energy.

Flashcard 51: What trophic level are primary producers located at?

Answer: First trophic level. Producers form the base of energy pyramids.

Flashcard 52: What is the 10% rule in energy transfer?

Answer: Only 10% of energy is transferred to the next trophic level. 90% is lost as heat during metabolic processes.

Flashcard 53: Find the energy transferred to the next level if 5000 J is consumed.

Answer: 500 J. Apply the 10% rule: $5000 \times 0.1 = 500$ J.

Flashcard 54: Calculate energy efficiency if 50 J is transferred from 500 J.

Answer: 10%. $\frac{50}{500} \times 100 = 10$% efficiency.

Flashcard 55: What is the typical shape of an energy pyramid?

Answer: Pyramid shape. Energy decreases at each ascending level.

Flashcard 56: Identify the primary source of energy in most ecosystems.

Answer: The Sun. Solar radiation drives photosynthesis in producers.

Flashcard 57: What is the effect of energy loss on ecosystem structure?

Answer: Fewer organisms at higher trophic levels. Energy constraints limit higher level populations.

Flashcard 58: Calculate the energy loss if 5000 J is reduced to 500 J in the next level.

Answer: 4500 J. Energy lost: $5000 - 500 = 4500$ J.

Flashcard 59: Identify the type of organism at the base of an energy pyramid.

Answer: Producers. Autotrophs capture solar energy at the base.

Flashcard 60: What is the typical shape of an energy pyramid?

Answer: Pyramid shape. Energy decreases at each ascending level.

Flashcard 61: Find the percentage of energy transferred if 300 J is passed from 3000 J.

Answer: 10%. $\frac{300}{3000} \times 100 = 10$% efficiency.

Flashcard 62: Identify the term for organisms that consume producers.

Answer: Primary consumers. Herbivores that eat producers directly.

Flashcard 63: Calculate energy transfer if 2000 J is available and 10% is passed on.

Answer: 200 J. 10% of 2000 J equals 200 J transferred.

Flashcard 64: Identify the unit commonly used to measure energy in ecosystems.

Answer: Joules (J). Standard unit for measuring energy transfer.

Flashcard 65: What term describes the 90% of energy not transferred to the next level?

Answer: Energy loss. Energy dissipated and unavailable for transfer.

Flashcard 66: Identify the process by which energy is lost as heat in organisms.

Answer: Respiration. Cellular process that releases thermal energy.

Flashcard 67: Which law of thermodynamics explains energy loss as heat?

Answer: Second law of thermodynamics. States energy becomes less useful over time.

Flashcard 68: What is the role of decomposers in energy flow?

Answer: Decomposers break down dead matter and recycle nutrients. They return energy to the ecosystem base.

Flashcard 69: Find total energy loss if 1000 J is at first level, reaching 10 J at third.

Answer: 990 J. Total lost: $1000 - 10 = 990$ J.

Flashcard 70: Calculate the energy available at the fourth trophic level if 1000 J starts at the first.

Answer: 1 J. Three 10% transfers: $1000 \times 0.1^3 = 1$ J.

Flashcard 71: What is the role of decomposers in energy flow?

Answer: Decomposers break down dead matter and recycle nutrients. They return energy to the ecosystem base.

Flashcard 72: Find total energy loss if 1000 J is at first level, reaching 10 J at third.

Answer: 990 J. Total lost: $1000 - 10 = 990$ J.

Flashcard 73: What is the energy efficiency of a trophic level if 25 J is transferred from 250 J?

Answer: 10%. $\frac{25}{250} \times 100 = 10\%$ efficiency.

Flashcard 74: What term describes the energy trapped by producers from sunlight?

Answer: Gross primary productivity. Total energy captured through photosynthesis.

Flashcard 75: Find the percentage of energy transferred if 300 J is passed from 3000 J.

Answer: 10%. $\frac{300}{3000} \times 100 = 10$% efficiency.

Flashcard 76: Calculate energy efficiency if 50 J is transferred from 500 J.

Answer: 10%. $\frac{50}{500} \times 100 = 10$% efficiency.

Flashcard 77: Identify the process by which producers capture solar energy.

Answer: Photosynthesis. Converts light energy into chemical energy.

Flashcard 78: What is the relationship between biomass and energy in ecosystems?

Answer: Biomass decreases as energy decreases up the trophic levels. Less biomass supports higher trophic levels.

Flashcard 79: What is the 10% rule in energy transfer?

Answer: Only 10% of energy is transferred to the next trophic level. 90% is lost as heat during metabolic processes.

Flashcard 80: What is the energy available to herbivores from plants called?

Answer: Net primary productivity. Energy remaining after plant respiration.