All flashcards
Flashcard 1: Which molecule is the main usable energy currency for cells?
Answer: ATP. Universal energy molecule that powers cellular processes.
Flashcard 2: Identify the trophic level of grass in the chain: grass → rabbit → fox.
Answer: Producer. First trophic level that makes food through photosynthesis.
Flashcard 3: Which option best describes a food web compared with a food chain?
Answer: A network of interconnected feeding relationships. Shows multiple pathways, unlike a single linear chain.
Flashcard 4: What term describes organisms that break down dead organisms and wastes into simpler substances?
Answer: Decomposers. Recycle nutrients by breaking down organic matter to inorganic forms.
Flashcard 5: What happens to most energy at each trophic level in a food chain?
Answer: It is lost as heat through life processes. Only ~10% transfers up; rest powers metabolism and movement.
Flashcard 6: What is the key difference between how matter and energy move through ecosystems?
Answer: Matter cycles; energy flows one-way and is lost as heat. Matter recycles between organisms; energy cannot be recycled.
Flashcard 7: What is the main cellular process that releases usable energy from glucose?
Answer: Cellular respiration. Breaks down glucose to release ATP for cellular work.
Flashcard 8: What is the correct word for an organism that gets energy by consuming other organisms?
Answer: Heterotroph (consumer). Must eat other organisms because they cannot produce their own food.
Flashcard 9: What is the correct word for an organism that makes its own food from inorganic materials?
Answer: Autotroph (producer). Self-feeders that produce organic molecules from inorganic sources.
Flashcard 10: What process do producers use to convert light energy into chemical energy in glucose?
Answer: Photosynthesis. Converts light energy to chemical bonds in glucose molecules.
Flashcard 11: What is the primary source of energy for most ecosystems on Earth?
Answer: Sunlight (solar energy). Powers photosynthesis, starting the energy flow through all food chains.
Flashcard 12: Identify the trophic level of fox in the chain: grass → rabbit → fox.
Answer: Secondary consumer. Carnivore that eats primary consumers.
Flashcard 13: What are the main products of photosynthesis?
Answer: Glucose and O2. Sugar stores energy; oxygen is released as byproduct.
Flashcard 14: What are the main reactants of photosynthesis?
Answer: CO2 and H2O (with light energy). Starting materials that combine to form glucose.
Flashcard 15: Which statement is evidence that plants increase biomass by taking in matter from the air?
Answer: Plants take in CO2 and build sugars and tissues. Carbon from air becomes plant mass through photosynthesis.
Flashcard 16: What are the main reactants of cellular respiration?
Answer: Glucose and O2. Breaks down sugar using oxygen to release energy.
Flashcard 17: Identify the trophic level of rabbit in the chain: grass → rabbit → fox.
Answer: Primary consumer. Herbivore that directly eats producers.
Flashcard 18: What are the main products of cellular respiration?
Answer: CO2, H2O, and ATP (plus heat). Releases stored energy as ATP while producing waste gases.
Flashcard 19: Which option best traces matter in a carnivore: does it come from sunlight or from eaten organisms?
Answer: From eaten organisms (food becomes body matter). Matter transfers through food chains, not directly from sun.
Flashcard 20: Which direction do arrows point in a food chain: from eater to food, or from food to eater?
Answer: From food to eater (direction of energy transfer). Shows energy flow from source to recipient.
Flashcard 21: Which evidence best supports that energy decreases at higher trophic levels: biomass or DNA similarity?
Answer: Biomass (or energy) pyramid data. Biomass decreases at each level due to energy loss as heat.
Flashcard 22: If a food chain is grass → rabbit → fox, what is the rabbit’s trophic role?
Answer: Primary consumer (herbivore). Eats producers (grass) and is eaten by secondary consumers.
Flashcard 23: If a plant contains carbon atoms, which molecule supplied most of that carbon?
Answer: Carbon dioxide (CO2) from the air. Plants absorb CO2 during photosynthesis to build glucose.
Flashcard 24: Which trophic level contains organisms that make their own food?
Answer: Producers (first trophic level). Only producers can convert inorganic matter into organic food.
Flashcard 25: What does ATP represent in cells when tracing energy through organisms?
Answer: Usable chemical energy for cell work. ATP stores energy from food in a form cells can use immediately.
Flashcard 26: Identify the direction of arrows in a food chain: from predator to prey or prey to predator?
Answer: From food to eater (prey to predator). Arrows show energy flow direction from source to consumer.
Flashcard 27: Which type of organism is a consumer, and where does its energy come from?
Answer: Heterotroph; eating other organisms. Must consume other organisms to obtain energy and matter.
Flashcard 28: Which type of organism is a producer, and what is its energy source?
Answer: Autotroph; sunlight or chemical energy. Makes own food from inorganic sources without eating others.
Flashcard 29: What is the role of decomposers in tracing matter through an ecosystem?
Answer: Break down dead matter and recycle nutrients. They return atoms from dead organisms to soil and atmosphere.
Flashcard 30: What process transfers energy from sunlight into chemical energy in glucose?
Answer: Photosynthesis. Converts light energy into chemical bonds in glucose molecules.