2. Levels of Organization & Relationships (2.1)
State Standard
SB4A. Investigate the relationships among organisms, populations, communities, ecosystems, and biomes.

3. Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Ecology
Scientific discipline in which the relationships among living organisms and the interaction the organisms have with their environments are studied
Ecologists observe, experiment, and model using a variety of tools and methods.

4. A thin layer around Earth.
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
The Biosphere
A thin layer around Earth.
Extends several kilometers above the Earth’s surface.
Extends several kilometers below the ocean’s surface.
The term biosphere includes all organisms and the environments in which they live (biotic and abiotic factors).

5. Abiotic and Biotic Factors
Chapter 2
Abiotic and Biotic Factors

6. Living (and once-living) factors in an organism’s environment.
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Biotic Factors
Living (and once-living) factors in an organism’s environment.
Abiotic Factors
Nonliving factors in an organism’s environment.
Organisms adapt to survive in the abiotic factors present in their natural environment.

7. Levels of Organization
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Levels of Organization
Levels increase in complexity as the numbers and interactions between organisms increase.
Organism - Individuals
Population - includes all the organisms in the same species in a
given area.
Community - a collection of populations that interact with each other
in a given area.
Ecosystem - includes all biotic and abiotic factors in a given area.
Biome – A group of ecosystems in the same region having similar types
of vegetation governed by similar climate conditions.
Biosphere – all organisms and the environments in which they live.

8. The lowest level of organization is the individual organism itself.
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
The lowest level of organization is the individual organism itself.
Organisms of a single species that share the same geographic location at the same time make up a population.
A community is a group of interacting populations that occupy the same geographic area at the same time.

9. Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
An ecosystem is a biological community and all of the abiotic factors that affect it.
A biome is a large group of ecosystems that share the same climate and have similar types of communities.

10. Ecosystem Interactions
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Ecosystem Interactions
A habitat is an area where an organism lives.
A niche is the role or position that an organism has in its environment.

11. Community Interactions
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Community Interactions
Competition
Occurs when more than one organism uses a resource at the same time
Predation
Many species get their food by eating other organisms.

12. Symbiotic Relationships
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Symbiotic Relationships
The close relationship that exists when two or more species live together
Mutualism
- Both organisms benefit

13. Clown Fish & Sea Anemone
Bee & Flowering Plant
Mutualism

14. Symbiotic Relationships
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Symbiotic Relationships
The close relationship that exists when two or more species live together
Mutualism
- Both organisms benefit
Commensalism
- One benefits while the other is unaffected

15. Bristle Worm
Hermit Crab
Commensalism

16. Symbiotic Relationships
Chapter 2
Principles of Ecology
2.1 Organisms and Their Relationships
Symbiotic Relationships
The close relationship that exists when two or more species live together
Mutualism
- Both organisms benefit
Commensalism
- One benefits while the other is unaffected
Parasitism
- One benefits while the other is harmed

17. Wasp Larvae & Tomato Hornworm
Tick & Human
Parasitism

18. Chapter 2
Principles of Ecology