⭐ UNIT 1: Ecosystem Interactions & Energy

9th grade Science class FHS

What is an ecosystem?

A community of living things plus the nonliving things they interact with.

What are biotic factors?

Living parts of an ecosystem (plants, animals, bacteria).

What are abiotic factors?

Nonliving things (sunlight, water, soil, temperature).

What is a food chain?

A simple model showing how energy moves from one organism to the next.

What is a food web?

Many connected food chains showing how energy actually flows in an ecosystem.

What is a producer?

An organism that makes its own food (plants, algae).

What is a consumer?

An organism that eats other organisms.

What is a decomposer?

Breaks down dead things and returns nutrients to the soil (fungi, bacteria).

How much energy passes from one level to the next?

Only 10% of the energy moves up; the rest is lost as heat.

Why are there fewer predators than prey?

Less energy is available at the top of the energy pyramid.

What is a limiting factor?

Anything that controls population size (food, water, space, predators).

What is carrying capacity?

The largest number of organisms an ecosystem can support.

What is competition?

When organisms fight for the same resources.

What is predation?

One organism (predator) hunts/eats another (prey).

What is mutualism?

Both organisms benefit.

What is commensalism?

One benefits, the other is not affected.

What is parasitism?

One benefits, the other is harmed.