1. Study of interactions between organisms and their environments.
Ecology
Study of interactions between organisms and their environments.

2. Biotic Factors Biosphere – life-supporting layer of Earth
Biotic factors – all living organisms in a
biosphere

3. Abiotic Factors Nonliving factors in an environment Examples:
Air currents
Temperature
Moisture
Light
Soil

4. Organization of Life Biosphere Ecosystems Communities Populations
Organisms

5. Feeding Relationships
Autotrophs
Heterotrophs
Carnivores
Omnivores
Herbivores
Decomposers

6. Trophic Relationships
Autotrophs
1st level consumers (herbivores)
2nd level consumers
3rd level consumers
4th level consumers (top predators)

8. RULE OF 10
Only 10% of energy is transferred from one trophic level to the next.
Example:
It takes 100 kgs of plant materials (producers) to support 10 kgs of herbivores
It takes 10 kgs of herbivores to support 1 kg of 1st level predator

9. Symbiosis – “living together”
Symbiosis Type
Species A
Species B
Commensalism
+ (benefit)
0 (neutral)
Mutualism
Parasitism
- (harmed)

10. Water cycle
Evaporation
Transpiration
Precipitation
Runoff
Groundwater

11. Carbon cycle Combustion Photosynthesis Respiration Decomposition
Fossil fuels

12. Nitrogen cycle Atmospheric nitrogen Runoff Fertilizers Decomposition
Nitrogen fixing
Synthesis of amino acids