All Flashcards
Define trophic level.
Position an organism occupies in a food chain or food web.
Define autotroph.
Organism that produces its own food, using sunlight or chemical energy.
Define heterotroph.
Organism that obtains energy by consuming other organisms.
Define primary consumer.
An organism that eats producers (herbivore).
Define secondary consumer.
An organism that eats primary consumers (carnivore).
Define tertiary consumer.
An organism that eats secondary consumers (top carnivore).
Define food chain.
Linear sequence of organisms through which nutrients and energy pass as one organism eats another.
Define food web.
Interconnected network of food chains in an ecosystem.
Define scavenger.
Organism that consumes dead animals.
Define detritivore.
Organism that feeds on dead organic material (detritus).
Define decomposer.
Organism that breaks down dead organic matter into simpler substances.
Define mutualism.
Symbiotic relationship where both organisms benefit.
Define commensalism.
Symbiotic relationship where one organism benefits and the other is neither harmed nor helped.
Define parasitism.
Symbiotic relationship where one organism benefits and the other is harmed.
Define keystone species.
Species with a disproportionately large impact on its ecosystem relative to its abundance.
What is the 10% rule?
Only about 10% of the energy is transferred to the next trophic level; the rest is lost as heat.
Explain the importance of decomposers.
They recycle nutrients by breaking down dead organic matter, making nutrients available to producers.
What is resource partitioning?
When species divide a limited resource to avoid direct competition, allowing them to coexist.
Why are food webs more accurate than food chains?
Food webs show the complex, interconnected feeding relationships in an ecosystem, while food chains are simplified linear sequences.
Describe the role of producers in an ecosystem.
Producers are the foundation of the food web, converting sunlight into energy that supports all other organisms.
How do predator-prey relationships regulate population sizes?
Predators control prey populations, preventing overpopulation, while prey availability influences predator numbers.
Explain the significance of keystone species.
Keystone species maintain the structure and function of their community; their removal can cause dramatic ecosystem changes.
How does competition influence natural selection?
Species better adapted to access limited resources are more likely to survive and reproduce, driving evolutionary change.
What are the main differences among primary, secondary, and tertiary consumers?
Primary consumers eat producers, secondary consumers eat primary consumers, and tertiary consumers eat secondary consumers.
Explain the difference between a scavenger and a detritivore.
Scavengers eat dead animals, while detritivores break down dead tissues and waste products.
Explain the 10% rule.
Only about 10% of the energy is transferred from one trophic level to the next; the rest is lost as heat.
What is resource partitioning?
When species divide a niche to avoid direct competition for resources.
How do predator-prey relationships regulate populations?
Predators control prey populations, preventing overpopulation; prey evolve defenses.
Why are decomposers important?
They recycle nutrients by breaking down dead organic matter, making nutrients available for producers.
What is the role of producers?
They convert sunlight into energy through photosynthesis, forming the base of the food chain.
How does energy loss affect food chains?
Limits the length of food chains because energy is lost as heat at each trophic level.
Explain the importance of keystone species.
They maintain the structure and function of the community; their removal can lead to ecosystem collapse.
What is the difference between a food chain and a food web?
A food chain is a simple linear sequence, while a food web is a complex network of interconnected food chains.
How does competition lead to natural selection?
Species better adapted to access resources are more likely to survive and reproduce, passing on their traits.
What is the role of scavengers in an ecosystem?
Scavengers consume dead animals, which helps to remove decaying matter and prevent the spread of disease.
Describe the flow of energy through trophic levels.
Energy flows from producers to consumers, with approximately 10% being transferred to each successive level, and the rest lost as heat.