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Ostrander chapter 1
Populations and communities
Term | Definition |
---|---|
Organism | A living thing |
Biotic Factor | Living or once living organism |
Habitat | An environment that provides the things a specific organism needs to live, grow, and reproduce. |
Abiotic Factors | Nonliving factors of an ecosystem. Examples are: Sun, air, soil, water, temperature. |
Species | A group of organisms that can mate with each other and produce offspring |
population | All the members of the same species living in a particular area. Example: 50 squirrels |
Community | All the different populations that live together. Example Robin, Squirrels, spruce trees |
Ecosystem | The community of organisms living together and includes all of the abiotic factors. |
Ecology | The study of how organisms interact with each other and with their environment. |
Birth Rate | The number of births per 1,000 individuals for a given time period |
Death rate | The number of deaths per 1,000 individuals for a given time period. |
Immigration | Moving Into a population |
Emmigration | Means moving out or Exiting a population |
Population Density | The numbers of individuals in an area. |
Limiting Factor | An environmental factor that causes a population to stop growing. |
Examples of limiting factors include | Weather conditions, space, food and water. |
Carrying capacity | The largest population an area can support. |
Formula for population density | Number of individuals divided by Unit Area |
Natural selection | Organisms that are best adapted to their environment will most likely survive. |
Adaptation | The behavior and physical characteristics that allow organisms to live successfully in their environments. |
Niche | The role of an organism in its habitat. How it gathers food, what it eats, and the physical conditions of the environment it lives in. |
Competition | The struggle for organisms to survive as they try to use the same limited resources. |
Predation | An interaction in which one organism kills another for food. |
Predator | The organism that kills for food. |
Prey | The organism that is killed and eaten. |
Symbiosis | Is a relationship in which 2 species live closely together and it least one benefits from the relationship. |
Mutualism | A relationship in which both species benefit. Example: Bee and a flower. |
Commensalism | A relationship in which one species benefits and the other is neither helped nor harmed. Example: A bird nest in a tree. |
Parasitism | A relationship where one species gains and the other is harmed. |
Example of parasitism | Tick on a dog. |
Parasite | The organism that benefits in parasitism. Tick |
Host | The organism that is harmed in parasitism. The dog. |