Levels oF Organization
EcologyStudy of interac/ons between organisms and their environment (habitat).
Levels of Ecology
We will study Ecosystems in Ecology Unit, Popula7ons in Evolu7on Unit, andOrganisms in Gene7cs Unit.
Levels of Ecology:
BIOSPHERE -‐ everywhere organisms live
BIOME -‐ regions with similar climates
ECOSYSTEM -‐ community plus its habitat; the interac/on between the living (bio0c) and nonliving (abio0c) factors
COMMUNITY -‐ group of various interac/ng species; the bio/c factors
POPULATION -‐ group of organisms of the same species
ORGANISMS -‐ individual living thing
Levels oF Organization
We can go further
Biosphere...Organism, then
Organ systems
Organs
Tissues
Cells
Molecules
Levels oF Organization
Ecosystems are filled with...
Abio0c Factors -‐ nonliving things (ex. rocks, lakes, ocean, clouds, soil, rain, temperature, etc.)
Bio0c Factors -‐ living things (ex. bacteria, fungi, plants, animals, etc.)
Ecosystems are filled with...
Abio0c Factors
affect the living factors
can help the living factors
can harm the living factors
Ecosystems are filled with...Bio0c Factors
Autotrophs (Producers)
“Self-feeders” – can make their own food by using the energy in sunlight to convert water and carbon dioxide into glucose (sugar)
ALL the energy in an ecosystem begins with the autotrophs/producers.
So, without autotrophs, there would be no life on this planet
Ex. plants and algae
Ecosystems are filled with...
Bio0c Factors
Heterotrophs (Consumers)
eat others
cannot make their own food, so must eat something
Ex. Rabbits, deer, insects
Ecosystems are filled with...Bio0c Factors
Heterotrophs (Consumers)
Types of Heterotrophs (Consumers):
Scavengers (Detrivores) - feed on tissue of dead organisms (both plants and animals); ex. vultures, crow, & shrimg
Herbivores - eat ONLY plants; ex. cows, giraffes, elephants
Carnivores - eat ONLY meat; ex. lions, tigers, sharks
Omnivores - eat BOTH plants and animals; ex. bears & humans
Decomposers - absorb dead material and break it down into simply nutrients and fertilizers; ex. bacteria & fungi
Food ChainsFood Chain
the energy flow from one trophic level to the other
simple and direct
involves one organism at each trophic level
NOTE: Producers are ALWAYS in the first
trophic level!!
Food WEBS
Food Web
depicts when organisms are involved in more than one food chain
most organisms can eat (or be eaten) by more than JUST one organism
more complex and involve lots of organisms in several, related food chains
Food CHAINS/WEBS
Food Chains/Webs
NOTE: direc/on of the arrows shows the direc/on of the energy flow and transfer of maNer, NOT “what ate what”
Food CHAINS/WEBS
Food Chains/Webs
NOTE: organisms can be at more than one trophic level, depending upon which food chain they are in
Where does all the E Go?
as you move up through a food chain or web, a lot of the energy is used by the organisms to “live & breathe”, not just grow to feed the next level; therefore, a lot of the energy is “lost” to heat at you move up the food chain or web.