Ecology Study Guide KEYCHAPTER 3

1. Define the following terms.a. Ecology - the study of the interactions and interdependent

relationships between organisms and their environmentb. Producer/Autotroph - an organism that makes their own food

either by the sun or from chemicalsc. Consumer/Heterotroph - an organism that needs to eat other

organisms in order to get energyd. Herbivore - an organism that eats plants onlye. Carnivore - an organism that eats animals onlyf. Omnivore - an organism that eats both plants and animalsg. Decomposer - an organism that breaks down dead organisms

and brings nutrients back to the environmenth. Scavenger - an organism that eats carrion and left over

animals i. Biomass - the amount of living tissue in the environment

2. What is the order from organism to biosphere?•Organism population community ecosystem

biosphere

3. What is an energy pyramid and how does energy flow through this cycle?•An energy pyramid is a model to explain the transfer of

energy between feeding relationships in the environment. The higher up the energy pyramid the less amount of the sun’s energy is attained. Producers get 100% of the sun’s energy and as you move up trophic levels, only 10% of the energy is transferred.

4. What is the difference between biotic and abiotic factors and give an example of each.• Biotic factors are the living things found in the environment.

Ex: trees, birds, bugs• Abiotic factors are the non-living things found in the

environment. Ex: water, clouds, temperature

5. Why are decomposers always the final organism in a food chain or web? What is their role in the environment?• Decomposers are always the final organism in a food chain or

web because all organisms will eventually die and the decomposers will bring the nutrients back into the environment.

6. What are the three types of nutrient cycles were talked about in class? What is their importance to our environment? • The three nutrient cycles are the water cycle, carbon cycle, and

nitrogen cycle. These nutrient cycles are important in order to reuse the materials on earth or fix the nutrients into useable forms.

7. What is the difference between a food chain and a food web? • A food chain is a simple feeding relationship between lists of

organisms. A food web is a complex model of feeding relationships that contains many food chains.

8. In the food web, identify the:a. Producers - berries and shrubsb. Primary consumers - mouse,

grasshopper, squirrel and rabbitc. Secondary consumers - frog, fox

and snaked. Herbivores - grasshopper, squirrel

and rabbite. Carnivores - owl, fox, snake and

frogf. Omnivores - mouseg. What element is missing from this

food web? Abiotic factors & decomposers

9. List one food chain from the web above. • Shrub grasshopper frog snake owl

10. What is the difference between an organism’s habitat and niche?• Habitat is where an organism lives. Niche is the role an

organism plays in the environment.

11. What are the three types of symbiotic relationships in nature and how is each organism affected in it? Give an example of each.• Commensalism is when one organism benefits and the other in

not affected. Ex: polar bears and cyanobacteria• Parasitism is when one organism benefits and the other is

harmed. Ex: tick on a deer• Mutualism is when both organisms benefit. Ex: cleaning birds

and rhinos