Food Web/Keystone Species Flashcards
Define autotroph
An organism that produces its own food through photosynthesis or chemosynthesis
Examples include plants and certain bacteria.
Define heterotroph
An organism that cannot produce its own food and relies on consuming other organisms
Examples include animals and fungi.
What is a producer?
An organism that makes own food from plants
Typically refers to autotrophs like plants.
What is a consumer?
An organism that can’t make its own food and needs to eat other organisms for energy
Consumers can be herbivores, carnivores, or omnivores.
Define decomposer
An organism that breaks down dead organic material, returning nutrients to the ecosystem
Examples include fungi and bacteria.
What is a herbivore?
An organism that primarily feeds on plants
Examples include cows and rabbits.
What is a carnivore?
An organism that primarily feeds on other animals
Examples include lions and hawks.
What is an omnivore?
An organism that eats both plants and animals
Examples include humans and bears.
What are primary consumers?
Organisms that eat producers, primarily herbivores
They occupy the second trophic level.
What are secondary consumers?
Organisms that eat primary consumers, can be carnivores or omnivores
They occupy the third trophic level.
What are tertiary consumers?
Organisms that eat secondary consumers, often top predators
They occupy the fourth trophic level.
What happens to energy in an ecosystem?
About 90% of energy is lost as heat at each trophic level
This limits the number of trophic levels in an ecosystem.
What is a keystone species?
A species that has a disproportionately large effect on its environment relative to its abundance
Examples include sea otters and wolves.
Give an example of a keystone species
Sea otters
They help maintain kelp forest ecosystems by controlling sea urchin populations.
