Ecology is the study of organisms and their environment. An ecosystem includes both biotic (living) and abiotic (nonliving) factors that interact in a defined area. A habitat is the place an organism lives, while its niche describes its role. Food chains connect organisms as energy passes between prey and predators, while food webs illustrate complex feeding connections between multiple organisms in an ecosystem. Substances like carbon and oxygen are recycled as they move through the biosphere, biomes, communities, populations and individual organisms that make up ecological levels of organization.

1. Ecological Levels of
Organization

2. Video Questions:
Organisms in their
environment
1. The branch of biology devoted to the
study of organisms in their environment
is ________.
2. Two parts of an ecosystem are:
a. ________ nonliving
b. _______________ living
3. What is the difference between habitat
& niche?

3. 4. What is the difference between a food
chain and a food web?
5. Give an example of a substance being
recycled by the environment.

4. Biosphere
The part of the earth that
contains all living things.

5. Biome
Group of ecosystems that
have the same climate and
similar dominant
communities.

6. Ecosystem
All of the biotic and abiotic
factors in a defined area.

7. Community
Populations of living
organisms that live
together and interact with
each other in a defined
area.

8. Population
Group of organisms of one
type that live in the same
area.

9. Organism – an individual
living thing.
Consists of:
Groups of cells – includes
tissues, organs, and organ systems.
Cells – smallest functional unit of life.
Molecules – groups of atoms; smallest
unit of most chemical compounds.