1. What is the difference between a biotic factor and an abiotic factor? Biotic = living, abiotic = non-living. Biotic: animals, plants, people, etc. Abiotic: weather, temperature, rainfall, soil, etc.

Community = All living things in an area. 2. Name three types of community interactions that can affect an ecosystem. Community = All living things in an area. Competition: organisms of same or diff. species compete for resources. Predation: one animal hunts & feeds on another. Who is competing? Who are the predators?

2. Name three types of community interactions that can affect an ecosystem. Symbiosis: two species living closely together.

3. What is the difference between primary succession and secondary succession? Primary succession = changes in ecosystem where no plants or animals to start with.

3. What is the difference between primary succession and secondary succession? Secondary = changes after an existing community is disturbed, e.g. by forest fire, human impact.

4. How is an organism’s niche determined? Niche = an organism’s role in an ecosystem, what it does. Determined by what it eats, who eats it, where it lives (habitat).

4. How is an organism’s niche determined? Niche = an organism’s role in an ecosystem, what it does. Determined by what it eats, who eats it, where it lives.

All involve two species of organisms living close together. 5. How are the three types of symbiotic relationships different? Similar? Mutualism = both species benefit, e.g. flowers and bees. Commensalism = one benefits; other is not helped or hurt, e.g. whales and barnacles. Parasitism = one lives on or in the other and hurts it, e.g. tapeworms and cats. All involve two species of organisms living close together.

Sharks, hagfish, amphipods, etc. eat decaying flesh. 6. Summarize the role of organisms, including microorganisms, in maintaining the equilibrium of a marine ecosystem while a dead whale decays on the ocean floor. Sharks, hagfish, amphipods, etc. eat decaying flesh. Crabs, snails, worms eat leftovers and nutrients in sediment.

6. Summarize the role of organisms, including microorganisms, in maintaining the equilibrium of a marine ecosystem while a dead whale decays on the ocean floor. 3. Bacteria decompose bones. Mussels, clams, snails, crabs, worms feed on bacteria.

Equilibrium = Everything in balance Balance applet: http://phet.colorado.edu/en/simulation/balancing-act

Equilibrium = Everything in balance What happens if there are too many frogs….?

Equilibrium = Everything in balance What happens if there are too many grasshoppers….?

Equilibrium = Everything in balance Balance applet: http://phet.colorado.edu/en/simulation/balancing-act

Equilibrium = Everything in balance