Ecosystems Basics
All the living and nonliving parts that interact in one area.
What is an ecosystem?
Which organisms make their own food using energy from the sun?
Producers (plants).
What word describes matter moving through steps that repeat?
Cycle
What is the name for the series of changes in an ecosystem over time?
Succession
An organism which can make its own nutrients
What is a producer
Name two abiotic factors that help decide which organisms can live in an ecosystem.
What is water, temperature, sunlight?
In a food chain, which type of organism is always the first link on land?
Producers—on land, usually plants.
Name one place matter can come from that producers use to grow.
Air, soil, or water
What is the difference between primary succession and secondary succession?
Primary succession: plants/animals start living on new land. Secondary succession: plants/animals return to disturbed or damaged land.
An organism that breaks down the bodies of dead organisms
What is a decomposer
Term for all the living things in an ecosystem that depend on one another.
What is community?
What do we call organisms that break down dead bodies and wastes and return nutrients to the soil?
Decomposers.
How do decomposers help matter cycle back to producers?
Decomposers break down wastes and dead bodies, returning nutrients to the soil for producers to use.
Give two threats to healthy ecosystems listed in the text.
Examples: habitat loss, new species (invasive species), growing human population, overfishing, pollution, drought
An organism that needs to eat other organisms to survive
What is a consumer
Explain why ecosystems can be any size but still have the same basic parts.
What is every ecosystem—large or small—has interacting abiotic (nonliving) and biotic (living) parts that affect each other.
Give one example of a decomposer you can see.
Visible decomposer: mushroom, fly, earthworm.
Describe one way carbon is returned to the air in the carbon cycle.
Animals/humans breathe out carbon dioxide; decomposers release carbon dioxide when breaking down dead plants.
Explain how introducing a new species might make an ecosystem unstable.
A new species can compete with native species for resources, change food web relationships, or introduce diseases—causing imbalance and instability
A model that shows how matter and energy flow from one organism to another
What is the food chain
Define “stable ecosystem” and give one example of a condition that shows stability.
Stable ecosystem: one that meets the needs of multiple species year to year with only slight changes (example: a forest where species numbers stay fairly constant).
Explain why all organisms need a sufficient amount of producers to survive.
Producers make food (using sunlight) that provides matter and energy to all other organisms; without enough producers, consumers have no base food source.
Explain why matter must cycle for organisms to keep getting the materials they need.
If matter didn’t cycle, materials (nutrients, gases, water) that organisms need would run out because they would not be returned to the environment for reuse.
After a fire, which types of producers typically grow back first within 1–4 years? Explain why these producers return quickly.
Weeds, grasses, and flowering plants (producers that can regrow quickly because they can make their own food and often reproduce fast).
A model of the transfer of energy within a set of interconnected food chains.
What is a food web