Transcript 3.2 Energy Flow

3.2 Energy Flow
Main source of energy for life on Earth?
Sun
 Less than 1% used by living things

*some organisms rely on energy stored in
inorganic chemical compounds
Autotrophs/Producers
 capture
energy from sunlight or
chemicals and use it to produce
food
 Plants, algae, bacteria
(cyanobacteria, salt marsh)
 They are VERY important to energy
flow in the biosphere
Photosynthetic bacteria
 cyanobacteria
 Tidal
marsh
 salt marsh
Photosynthesis
Oh no! Light’s out!
 Chemosynthesis-use
chemical
energy to produce CHOs
 Done in the absence of light
 Some bacteria
 Volcanic vents, hot springs, tidal
marshes
Consumers
Heterotrophs = consumers rely on
other organisms for their energy
and food
Animals, fungi and many bacteria
Types of Heterotrophs

Herbivores eat only plants

Carnivores eat animals

Omnivores eat plants & animals
Herbivores (cont.)


Detritovoreseat plant and animal
remains and other dead matter
(detritus)
Decomposers break down organic
matter
Community Interactions
Competition
 Predation
 Symbiosis – two species live closely
together
1. Mutualism
2. Commensalism
3. Parasitism

What are you going to do…?
 Create/draw/color
a comic
illustrating the symbiotic
relationship between your two
organisms.
 Do NOT…I repeat, Do NOT use
the name of the relationship in
your comic!
1
2
Grassland
3
Suburb
4
Coniferous
Forest
5
Coniferous
Forest
6
Lake
7
Deciduous
Forest
Deciduous
Forest
8
Grassland
Suburb

What happens to the energy in an
ecosystem when one organism eats
another?

Energy flows in one direction
Sun  producers  consumers
Food Web
Trophic Levels
Each step in a food chain or food web
 Producers = 1st trophic level
 Consumers = 2nd, trophic level (3rd, 4th,
etc)
 Only about 10% of the energy available
within one trophic level is transferred to
organisms at the next trophic level

What shapes an ecosystem?
Biotic factors-the biological influences on
organisms w/i an ecosystem
 Examples:

Abiotic factors-nonliving factors that shape
ecosystems
 Examples:

Biotic and abiotic factors determine the
survival and growth of an organism and
the productivity of the ecosystem in which
it lives
 Habitat-the area an organism lives
(includes biotic and abiotic factors)
 Niche-full range of physical and biological
conditions in which an organism lives and
the way it uses the conditions
