Download Levels of organization - Piscataway High School

Ecology 1
Ecology:
study of interactions between organisms
and between organisms and their environment
Biosphere (ecosphere): All parts of planet in which life exists.
11 km below surface of ocean to 8 km above Earth’s surface
Levels of organization:
atoms
molecules
cells
tissues
organs
organ systems
organism
Levels of Organization in Biosphere:
Individual Organism
Population
Individuals of same species, in the same area
Community
Ecosystem
Biome
Different populations living in same area
Communities & nonliving (abiotic factors)
Ecosystems with same climate & similar communities
Autotrophs – make food
photosynthesis – use sunlight + CO2 + H2O
-make food + O2
chemosynthesis – use chemical energy
-to make food
Heterotrophs – eat other organisms for food
Herbivores – eat autotrophs
Carnivores – eat heterotrophs
Omnivores – eat both autotrophs & heterotrophs
Detrivores &Decomposers – eat dead organisms
and break down organic matter
What is the difference between a detritivore and a
decomposer?
The same: get food from dead organic matter
Different:
detrivores actually eat the organic matter
(like earthworms eating their way through the soil)
decomposers secrete enzymes to digest the organic matter and then
absorb the resulting molecules
(like bacteria or fungi).
detrivore=vulture
decomposer=bacteria
Energy Flow:
One direction:
from sun
to
autotrophs
to
heterotrophs
Food Chain:
Series of steps in which organisms transfer energy
by eating or being eaten
Food Web: Links all food chains in a community
Trophic Level:
Each step in food chain
Decomposers/detritivores
Top level carnivores (have no predators)
Second level carnivores eat other carnivores
First level carnivores that eat herbivores
Herbivores that eat autotrophs
Autotrophs make their own food
Ecological Pyramid
Compares relative amounts of energy , matter (biomass) or
numbers of individuals in trophic levels of food chains/webs
There are 3 types of Pyramids
Energy Pyramid
Only 10% of the energy available in a trophic level is passed to
organisms in the next level
Where does the other
90% go?
-used to do work
-lost as heat
170
1,700
17,000
170,000
Tertiary Consumers
0.01%
0.1%
1%
Problem: if first level has 1,000,000 calories of energy
available, how much will be available in the FOURTH
level?
1000
10,000
100,000
1,000,000
0.1%
1%
10%
100%
Biomass Pyramid
Compare amount of living organic matter (biomass) at
each trophic level
(amount of potential food available for each trophic level)
Pyramid of Numbers
Shows relative numbers
Of individuals at each
trophic level
Pyramid of Numbers
Corresponding
BIOMASS PYRAMID!!