AP Biology Flashcards: Energy Flow Through Ecosystems

What this deck covers

This deck focuses on Energy Flow Through Ecosystems, giving you a quick way to review the definitions, rules, and examples that matter most for AP Biology.

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: What type of pyramid is most useful for showing energy flow?

Answer: Energy pyramid. Shows energy availability decreasing at higher trophic levels.

Flashcard 2: Define 'biomass' in an ecological context.

Answer: The total mass of living matter within a given unit of environmental area. Includes all living organisms in a specific area or ecosystem.

Flashcard 3: Which organisms are considered primary producers?

Answer: Plants, algae, and some bacteria. Organisms capable of photosynthesis or chemosynthesis for energy production.

Flashcard 4: What is the difference between autotrophs and heterotrophs?

Answer: Autotrophs produce their own food; heterotrophs consume others for energy. Distinguishes self-feeding organisms from those requiring external food sources.

Flashcard 5: What does a biomass pyramid represent?

Answer: The total biomass at each trophic level. Shows the mass of organisms at each feeding level.

Flashcard 6: What is the main form of energy loss between trophic levels?

Answer: Heat. Most energy is lost as thermal energy during metabolism.

Flashcard 7: What is the main role of carnivores in an ecosystem?

Answer: To control the population of other consumers. Predators help maintain balance by preventing herbivore overpopulation.

Flashcard 8: Which trophic level has the most energy in an ecosystem?

Answer: Producers. Producers capture the most solar energy through photosynthesis.

Flashcard 9: Which trophic level directly consumes producers?

Answer: Primary consumers. Herbivores that feed on plants, algae, and other autotrophs.

Flashcard 10: What is the primary function of detritivores?

Answer: To consume decomposing organic matter. Feed on dead organic material, accelerating decomposition processes.

Flashcard 11: What is the significance of a keystone species?

Answer: A species on which other species in an ecosystem largely depend. Their removal causes dramatic changes throughout the entire ecosystem structure.

Flashcard 12: State the formula for net primary productivity (NPP).

Answer: NPP = GPP - R. GPP minus respiratory losses equals energy available for growth.

Flashcard 13: How does energy flow in an ecosystem?

Answer: From the Sun to producers to consumers to decomposers. Energy moves unidirectionally from sun through all trophic levels.

Flashcard 14: What is the significance of a keystone species?

Answer: A species on which other species in an ecosystem largely depend. Their removal causes dramatic changes throughout the entire ecosystem structure.

Flashcard 15: Define 'biomass' in an ecological context.

Answer: The total mass of living matter within a given unit of environmental area. Includes all living organisms in a specific area or ecosystem.

Flashcard 16: What percentage of energy is typically transferred from one trophic level to the next?

Answer: 10%. Known as the 10% rule due to metabolic inefficiencies.

Flashcard 17: Identify the first trophic level in an ecosystem.

Answer: Producers. Autotrophs that capture energy and create organic matter from inorganic sources.

Flashcard 18: What is the difference between a food chain and a food web?

Answer: A food chain is linear; a food web is complex and interconnected. Food webs show realistic multiple feeding relationships between organisms.

Flashcard 19: What term describes the rate at which energy is stored by producers in an ecosystem?

Answer: Primary productivity. Measures the rate of energy capture and storage by autotrophs.

Flashcard 20: Which organisms convert inorganic materials into organic ones?

Answer: Primary producers. Autotrophs synthesize organic compounds from carbon dioxide and water.

Flashcard 21: Define 'trophic level' in an ecosystem.

Answer: A position in a food chain occupied by a group of organisms with similar feeding mode. Groups organisms by their feeding relationships and energy transfer roles.

Flashcard 22: Which process converts solar energy into chemical energy in plants?

Answer: Photosynthesis. Light energy is captured and converted into glucose and oxygen.

Flashcard 23: Identify the role of apex predators in ecosystems.

Answer: Regulate the populations of prey species. Top predators control ecosystem structure through predation pressure.

Flashcard 24: Which trophic level directly consumes producers?

Answer: Primary consumers. Herbivores that feed on plants, algae, and other autotrophs.

Flashcard 25: Which type of organism is at the base of most aquatic food chains?

Answer: Phytoplankton. Microscopic photosynthetic organisms that form the aquatic food base.

Flashcard 26: What is the main role of carnivores in an ecosystem?

Answer: To control the population of other consumers. Predators help maintain balance by preventing herbivore overpopulation.

Flashcard 27: What term describes the rate at which energy is stored by producers in an ecosystem?

Answer: Primary productivity. Measures the rate of energy capture and storage by autotrophs.

Flashcard 28: What is the main form of energy loss between trophic levels?

Answer: Heat. Most energy is lost as thermal energy during metabolism.

Flashcard 29: How does energy flow in an ecosystem?

Answer: From the Sun to producers to consumers to decomposers. Energy moves unidirectionally from sun through all trophic levels.

Flashcard 30: What does GPP stand for in ecology?

Answer: Gross Primary Productivity. Total energy captured by producers before respiratory losses.

Flashcard 31: What is the primary source of energy for most ecosystems?

Answer: The Sun. Solar radiation powers virtually all ecosystems on Earth.

Flashcard 32: What does an energy pyramid illustrate?

Answer: The energy available at each trophic level in an ecosystem. Demonstrates decreasing energy availability up the food chain.

Flashcard 33: What percentage of energy is typically transferred from one trophic level to the next?

Answer: 10%. Known as the 10% rule due to metabolic inefficiencies.

Flashcard 34: Identify the process by which consumers obtain energy.

Answer: Cellular respiration. Breaks down glucose to release ATP for cellular functions.

Flashcard 35: Identify the process by which consumers obtain energy.

Answer: Cellular respiration. Breaks down glucose to release ATP for cellular functions.

Flashcard 36: What does GPP stand for in ecology?

Answer: Gross Primary Productivity. Total energy captured by producers before respiratory losses.

Flashcard 37: What is the primary function of detritivores?

Answer: To consume decomposing organic matter. Feed on dead organic material, accelerating decomposition processes.

Flashcard 38: What is the role of omnivores in food chains?

Answer: They consume both plants and animals. Mixed feeders that can occupy multiple trophic levels simultaneously.

Flashcard 39: Identify one way energy is lost between trophic levels.

Answer: As heat during metabolic processes. Cellular respiration releases unusable thermal energy to the environment.

Flashcard 40: What does the '10% rule' refer to in ecology?

Answer: Only 10% of energy is transferred to the next trophic level. Explains why energy transfer between trophic levels is highly inefficient.

Flashcard 41: What is the role of secondary consumers in a food chain?

Answer: They consume primary consumers. Carnivores that feed on herbivores in the food chain.

Flashcard 42: What is a food web?

Answer: A complex network of interconnected food chains in an ecosystem. Shows realistic feeding relationships with multiple pathways and connections.

Flashcard 43: What is the primary source of energy in a food web?

Answer: Solar energy. Sunlight powers photosynthesis that drives all food web energy.

Flashcard 44: What is the definition of a food chain?

Answer: A linear sequence of organisms through which nutrients and energy pass. Shows direct feeding relationships from producers to top consumers.

Flashcard 45: What is the definition of a food chain?

Answer: A linear sequence of organisms through which nutrients and energy pass. Shows direct feeding relationships from producers to top consumers.

Flashcard 46: Identify the role of decomposers in an ecosystem.

Answer: Break down dead material and recycle nutrients. Essential for returning nutrients to soil and maintaining ecosystem cycles.

Flashcard 47: Identify one way energy is lost between trophic levels.

Answer: As heat during metabolic processes. Cellular respiration releases unusable thermal energy to the environment.

Flashcard 48: Which organisms are considered primary producers?

Answer: Plants, algae, and some bacteria. Organisms capable of photosynthesis or chemosynthesis for energy production.

Flashcard 49: Which trophic level contains herbivores?

Answer: Primary consumers. They feed directly on producers like plants and algae.

Flashcard 50: What does an energy pyramid illustrate?

Answer: The energy available at each trophic level in an ecosystem. Demonstrates decreasing energy availability up the food chain.

Flashcard 51: What is the difference between autotrophs and heterotrophs?

Answer: Autotrophs produce their own food; heterotrophs consume others for energy. Distinguishes self-feeding organisms from those requiring external food sources.

Flashcard 52: Which process converts solar energy into chemical energy in plants?

Answer: Photosynthesis. Light energy is captured and converted into glucose and oxygen.

Flashcard 53: What is the role of secondary consumers in a food chain?

Answer: They consume primary consumers. Carnivores that feed on herbivores in the food chain.

Flashcard 54: Define 'ecological pyramid'.

Answer: A graphical representation showing biomass, energy, or numbers at each trophic level. Displays quantitative relationships between trophic levels in ecosystems.

Flashcard 55: What is the primary source of energy in a food web?

Answer: Solar energy. Sunlight powers photosynthesis that drives all food web energy.

Flashcard 56: What is the role of producers in an ecosystem?

Answer: Convert solar energy into chemical energy via photosynthesis. Form the foundation of all food webs by creating organic compounds.

Flashcard 57: Identify the role of decomposers in an ecosystem.

Answer: Break down dead material and recycle nutrients. Essential for returning nutrients to soil and maintaining ecosystem cycles.

Flashcard 58: Which organisms convert inorganic materials into organic ones?

Answer: Primary producers. Autotrophs synthesize organic compounds from carbon dioxide and water.

Flashcard 59: What is a food web?

Answer: A complex network of interconnected food chains in an ecosystem. Shows realistic feeding relationships with multiple pathways and connections.

Flashcard 60: What is the role of producers in an ecosystem?

Answer: Convert solar energy into chemical energy via photosynthesis. Form the foundation of all food webs by creating organic compounds.

Flashcard 61: What does the '10% rule' refer to in ecology?

Answer: Only 10% of energy is transferred to the next trophic level. Explains why energy transfer between trophic levels is highly inefficient.

Flashcard 62: Which trophic level has the most energy in an ecosystem?

Answer: Producers. Producers capture the most solar energy through photosynthesis.

Flashcard 63: Which type of organism is at the base of most aquatic food chains?

Answer: Phytoplankton. Microscopic photosynthetic organisms that form the aquatic food base.

Flashcard 64: What type of pyramid is most useful for showing energy flow?

Answer: Energy pyramid. Shows energy availability decreasing at higher trophic levels.

Flashcard 65: Identify the first trophic level in an ecosystem.

Answer: Producers. Autotrophs that capture energy and create organic matter from inorganic sources.

Flashcard 66: Define 'trophic level' in an ecosystem.

Answer: A position in a food chain occupied by a group of organisms with similar feeding mode. Groups organisms by their feeding relationships and energy transfer roles.

Flashcard 67: What does a biomass pyramid represent?

Answer: The total biomass at each trophic level. Shows the mass of organisms at each feeding level.