1. Ecology Study Guide KEY CHAPTER 3

2. 1. Define the following terms. a.Ecology - the study of the interactions and interdependent relationships between organisms and their environment b.Producer/Autotroph - an organism that makes their own food either by the sun or from chemicals c.Consumer/Heterotroph - an organism that needs to eat other organisms in order to get energy d.Herbivore - an organism that eats plants only e.Carnivore - an organism that eats animals only f.Omnivore - an organism that eats both plants and animals g.Decomposer - an organism that breaks down dead organisms and brings nutrients back to the environment h.Scavenger - an organism that eats carrion and left over animals i.Biomass - the amount of living tissue in the environment

3. 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. 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.

5. 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.

6. 8. In the food web, identify the: a.Producers - berries and shrubs b.Primary consumers - mouse, grasshopper, squirrel and rabbit c.Secondary consumers - frog, fox and snake d.Herbivores - grasshopper, squirrel and rabbit e.Carnivores - owl, fox, snake and frog f.Omnivores - mouse g.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

7. 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