1. Ecology!
The study of interactions among
organisms and their
environments

2. Levels of Organization


The biosphere is where all life exists
Ecosystems include living (biotic) and
non-living (abiotic) factors

3. Levels of Organization


Populations consist of organisms of the
same species living in an area
Communities have several populations
in an area
pg. 64-65

4. Energy Flow:
Producers
The SUN provides energy
 Producers make food
(autotrophic)

– Plants and some bacteria
are photosynthetic
– Some bacteria do
chemosynthesis

5. Energy Flow:
Consumers

Heterotrophs rely on other
organisms for their energy
– ie: herbivores, carnivores, omnivores,
detrivores, and decomposers

6. Food Chains

Energy is transferred through an
ecosystem when organisms eat or
are eaten

7. Trophic Levels

Feeding levels in a food chain or web
– 1st Trophic Level – Producers
– 2nd Trophic Level – 1st Order (Primary) Consumer…ETC

Each consumer depends on the trophic level
below it for energy!

8. Figure 3-8 A Food Web
Food Web
Section 3-2

Many food chains
together form a
food web
Pg. 71

9. Pyramid of Energy

10% of the energy at one trophic level
is available to the organisms at the
next level.

10. Biomass Pyramid
The amount of living tissue
and thus potential food
 Typically the greatest
biomass is at the base


11. Pyramid of Numbers
Relative number of individual
organisms at each level
 In certain ecosystems, it is NOT
pyramid shaped
