Energy Flow Through Ecosystems - AP Biology
- What type of pyramid is most useful for showing energy flow?
- Energy pyramid. Shows energy availability decreasing at higher trophic levels.
- Define 'biomass' in an ecological context.
- The total mass of living matter within a given unit of environmental area. Includes all living organisms in a specific area or ecosystem.
- Which organisms are considered primary producers?
- Plants, algae, and some bacteria. Organisms capable of photosynthesis or chemosynthesis for energy production.
- What does a biomass pyramid represent?
- The total biomass at each trophic level. Shows the mass of organisms at each feeding level.
- What is the main form of energy loss between trophic levels?
- Heat. Most energy is lost as thermal energy during metabolism.
- Which trophic level has the most energy in an ecosystem?
- Producers. Producers capture the most solar energy through photosynthesis.
- What is the primary function of detritivores?
- To consume decomposing organic matter. Feed on dead organic material, accelerating decomposition processes.
- State the formula for net primary productivity (NPP).
- NPP = GPP - R. GPP minus respiratory losses equals energy available for growth.
- How does energy flow in an ecosystem?
- From the Sun to producers to consumers to decomposers. Energy moves unidirectionally from sun through all trophic levels.
- What is the significance of a keystone species?
- It has an effect on community structure that is disproportionately large relative to its abundance. Unlike a dominant species, a keystone species may be uncommon, yet its removal can dramatically change species composition and diversity in the community.
- Identify the first trophic level in an ecosystem.
- Producers. Autotrophs that capture energy and create organic matter from inorganic sources.
- What is the difference between a food chain and a food web?
- A food chain is linear; a food web is complex and interconnected. Food webs show realistic multiple feeding relationships between organisms.
- Which organisms convert inorganic materials into organic ones?
- Primary producers. Autotrophs synthesize organic compounds from carbon dioxide and water.
- Define 'trophic level' in an ecosystem.
- 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.
- Which process converts solar energy into chemical energy in plants?
- Photosynthesis. Light energy is captured and converted into glucose and oxygen.
- Identify the role of apex predators in ecosystems.
- They occupy the top trophic level of a food web. Their predation can affect prey abundance and community structure, sometimes producing trophic cascades that reach lower trophic levels.
- Which trophic level directly consumes producers?
- Primary consumers. Herbivores that feed on plants, algae, and other autotrophs.
- Which type of organism is at the base of most aquatic food chains?
- Phytoplankton. Microscopic photosynthetic organisms that form the aquatic food base.
- What role do carnivores play in an ecosystem's energy flow?
- They are consumers that obtain energy by eating other animals. Carnivores pass energy along food chains and webs, and their predation can influence the abundance of their prey.
- What term describes the rate at which energy is stored by producers in an ecosystem?
- Primary productivity. Measures the rate of energy capture and storage by autotrophs.
- What is the primary source of energy for most ecosystems?
- The Sun. Solar radiation powers virtually all ecosystems on Earth.
- What percentage of energy is typically transferred from one trophic level to the next?
- 10%. Known as the 10% rule due to metabolic inefficiencies.
- Identify the process by which consumers obtain energy.
- Cellular respiration. Breaks down glucose to release ATP for cellular functions.
- What does GPP stand for in ecology?
- Gross Primary Productivity. Total energy captured by producers before respiratory losses.
- What is the role of omnivores in food chains?
- They consume both plants and animals. Mixed feeders that can occupy multiple trophic levels simultaneously.
- What does the '10% rule' refer to in ecology?
- Only 10% of energy is transferred to the next trophic level. Explains why energy transfer between trophic levels is highly inefficient.
- What is a food web?
- A complex network of interconnected food chains in an ecosystem. Shows realistic feeding relationships with multiple pathways and connections.
- What is the primary source of energy in a food web?
- Solar energy. Sunlight powers photosynthesis that drives all food web energy.
- What is the definition of a food chain?
- A linear sequence of organisms through which nutrients and energy pass. Shows direct feeding relationships from producers to top consumers.
- Identify one way energy is lost between trophic levels.
- As heat during metabolic processes. Cellular respiration releases unusable thermal energy to the environment.
- Which trophic level contains herbivores?
- Primary consumers. They feed directly on producers like plants and algae.
- What does an energy pyramid illustrate?
- The energy available at each trophic level in an ecosystem. Demonstrates decreasing energy availability up the food chain.
- What is the difference between autotrophs and heterotrophs?
- Autotrophs produce their own food; heterotrophs consume others for energy. Distinguishes self-feeding organisms from those requiring external food sources.
- What is the role of secondary consumers in a food chain?
- They consume primary consumers. Carnivores that feed on herbivores in the food chain.
- Define 'ecological pyramid'.
- A graphical representation showing biomass, energy, or numbers at each trophic level. Displays quantitative relationships between trophic levels in ecosystems.
- Identify the role of decomposers in an ecosystem.
- Break down dead material and recycle nutrients. Essential for returning nutrients to soil and maintaining ecosystem cycles.
- What is the role of producers in an ecosystem?
- Convert solar energy into chemical energy via photosynthesis. Form the foundation of all food webs by creating organic compounds.