Section 1-3
2. An organism's niche is more than their place in a food chain, it includes everything the organism does and everything it needs in its environment.
3. Organism's niche includes:
a. The place in which it lives.
b. The food it eats.
c. The organisms that feed on it.
d. The organisms that interact with it in other ways.
e. The amount of light and humidity it needs.
f. The physical conditions in which it can survive.
4. Two or more species can share the same habitat or similar habitats and food requirements but two or more species cannot share the same niche.
Competition:
1. The interaction known as competition is the resut of not having enough resources to go around, so the organisms must struggle with one another to get the things that they need to survive.
2. Regardless of the more specific causes, competition can have a powerful effect on the size and location of a population in an ecosystem.
Predation:
1. Living things that catch, kill, and eat other living things are called predators.
2. The organisms that are eaten by predators are called prey.
3. Predation plays an important part in shaping the structure of communities. They help reduce the size of the prey population and help maintain the diversity in an ecosystem.
Symbiosis:
1. Symbiosis is a close relationship between two organisms in which one organism lives near, on, or even inside another organism and in which at least one organism benefits.
2. There are three categories of symbiosis:
a. Commensalism: one of the organisms benefits and the other is not harmed
b. Mutualism: both organisms benefit
c. Parasitism: One organism benefits and the other is harmed
3. Ecologists often regard parasitism and predation as being different forms of the same basic kind of interaction:
In predation: the predator kills its prey before it eats it.
In parasitism: the parasite usually live on or in a much larger organism and feeds on it while it is still alive.
Section 1-3 Notes Continued...
