36 terms


Name the three energy roles that organisms fill in an ecosystem.
Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.
How do organisms in each of the three energy roles obtain energy?
An organism that can make its own food is a producer. An organism that obtains energy by feeding on other organisms is a consumer.. Decomposers break down wastes and dead organisms and return the raw materials to the ecosystem.
What are the energy roles of the following organisms in a pond ecosystem: tadpole, algae, heron?
Tadpole: Consumer, Algae: Producer, Heron: Consumer
What is a food chain? What is a food web?
A food web consists of many interconnected food chains. A food chain is a series of events in which one organism eats another and obtains energy.
Why is a food web a more realistic way of portraying an ecosystem than is a food chain?
webs show the interdependence between organisms
What does an energy pyramid show?
A diagram called an energy pyramid shows the amount of energy that moves from one feeding level to another in a food web.
How does the amount of energy available at one level of an energy pyramid compare to the amount of energy available at the next level up?
Only 10 percent is transferred up. As you move up the food chain there is less energy.
Why are there usually few organisms at the top of an energy pyramid?
Since about 90 percent of the energy is lost at each step, there is not enough energy to support many feeding levels in an ecosystem.
Why are invasive species a major threat to our environment?
invasive species have no natural controls, no predators
Difference between native, non-native, and invasive species?
Non-native species not from the area. Invasive species can cause harm to the environment. Native species already exist in the habitat.
What is the advantage of a simulation model ?
Time can be stopped or sped up, don't have to go to the lake everyday,
What is the disadvantage of a simulation model?
Not actually the same as being in the true environment, only a few organisms are displayed
What is algae?
common name of a huge group of organisms that live in the water and have chlorophyll and photosynthesis
What is a trophic level?
a feeding level in a food web or chain
What is a producer?
plants, algae and bacteria that make their own food
What is a consumer?
any organism that gets its food by eating other organisms
What is a herbivore?
plant eater, feed on producers (ex: a rabbit eats plants)
What is a carnivore?
Meat eater, they eat herbivores or other carnivores. (ex: wolf eats a rabbit)
What is a decomposer?
an organism that feeds off the remains or wastes of other organisms (ex. mushroom bacteria)
What is a food chain?
It traces the path of energy as it moves from one organism to the next in an ecosystem
What is a food web?
a system of several overlapping food chains
Where is most of the energy in the pyramid in a food chain?
at the bottom
How does most energy enter most ecosystems?
as a producer from the sun
What happens as the energy moves up the pyramid in a food chain?
Each level has 10% less energy available than the level below
What is a native speices?
From that area
What is a non-native species?
Not from the area, not harmful
What is an invasive species?
not from the area, and harmful to the ecosystem
What do we call an organism that lives on or in another organism?
What is a host?
an organism that parasites eat off of (i.e.: dogs/wolves)
What is natural selection?
characteristics that makes an individual better suited for its environment
What are the 3 major types of interactions amoung organisms?
competition, predation and symbosis
What do we call the struggle between organisms to survive as they attempt to use the same limited resources?
What is symbiosis?
a close relationship between two species that benefits at least one of the species
What is mutualism?
a relationship in which both species benefits
What is commensalism?
a relationship in which one species benefits and the other species is neither helped nor harmed
What is parasitism?
When one organism living in or on another organism and harming it