| A | B |
|---|
| symbiotic relationship | exists between organisms of two different species that live together in direct contact |
| mutualism | a symiotic relationship where both organisms benefit because the two organisms work closely together. They help each other survive. |
| parasitism | a symbiotic relationship where one organism benefits at the expense of the other organism. In general, the parasite does not kill the host. |
| commensalism | a symiotic relationship in which one organism benefits and the other organism isn't affected. |
| biotic factors | factors that are alive or living |
| abiotic factors | factors that are nonliving |
| limiting factor | any factor that limits the number of individuals in a population, such as space and water |
| population size | simple - gives one number only |
| population density | complex - tells how many live in an area AND the size of the area...two numbers |
| a divide | separates different watersheds |
| delta | formed by sediment deposited where a stream or river empties into a still body of water |
| water table | the top of the zone of saturation |
| zone of saturation | completely saturated with water |
| zone of aeration | exisits above the water table that has not yet been saturated with water |
