Name:____________________________________________________________________Test Date:_______________
Study Guide Ecology Assessment
Ecology -study of interactions that take place between organisms and their environment.
Abiotic factors: non-living factors in the environment
Examples: air, temperature, light, soil, water, rocks, and nutrients
Biotic factors: living or dead organisms in the environment
Examples: cat, plant, dead worm, wooden stick
Producer: organisms that use sunlight to produce food (plants)
Consumer: organisms that eat (consume) other organisms for energy
Decomposers: organisms that get their food by breaking down the remains of
dead organisms or animal waste-“nature’s recyclers”
Examples: bacteria and fungi
Scavenger: animals that eats on other dead animals.
Competition- when two or more individuals or populations try to use the same limited
resource such as food, water, shelter, space or sunlight
There are 2 major reasons for competition:
1. carrying capacity- the largest population that an environment can support at
any given time
2. limiting factor- a factor that limits population growth such as food, water,
shelter, space or sunlight
Predation-when one organism preys on another organism
There are two organisms involved:
predator- an animal that hunts other animals
prey- an animal that is hunted
Symbiosis- a close long term relationship between two different organisms
Three types of symbiosis:
1. Mutualism (+/+):both species benefit
 Ants living in the tropical acacia trees
2. Commensalism (+/0): one species benefits and the
other species is unaffected
 Spanish moss grows on the branches of trees.
3. Parasitism (+/-):one species benefits and the
other species is harmed
 Ticks feed on dogs.
Five Levels of Environmental Organization:
Organism (Level 1) any living thing that can live on its own-Example: 1 king penguin
Population (Level 2) group of organisms of the same species living in one area
Example: 4-5 king penguins in one area
Community (Level 3) made up of all of the populations of different species in an area
but not the abiotic factors of that environment. Example: king penguin, fish, algae, bear
Ecosystem (Level 4) made up of a community of organisms and its abiotic environment
Example: king penguin, fish, algae, polar bear, air, water temperature, wind
Biosphere (Level 5) the part of Earth where life exists
Definitions:
habitat- the part of an ecosystem in which an animal lives
niche- role an organism plays in an ecosystem, its habitat,
and how an organism interacts with the biotic and
abiotic factors in its environment.
Human niche=consumer
scavenger-organism that feeds on dead animals
carnivore- consumer that eats only animals (wolf)
omnivore- consumer that eats a variety of meat, fruit and vegetables
herbivore- consumer that eats plants (cow)
food chain- diagram that shows the flow of energy, represented by an arrow.
food web- shows all the ways energy flows to and from all organisms in an
ecosystem
energy pyramid- Base (producers) contains
the most energy and most individuals;
the top has the fewest organisms
and the least amount of energy.