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chapter 4: 1,2,3
| Term | Definition |
|---|---|
| Ecology | the study of how organisms interact with each other and their environments |
| species | is a group of individuals that interbreed and produce fertile offspring. |
| population | members of a species that live in the same area at the same time make up a population |
| community | all the populations in a particular area |
| ecosystem | includes all of the living things and their physical environments within a particular area. |
| biosphere | includes all parts of earth that host life. |
| biotic factors | parts of an ecosystem that are living or that used to be living. |
| abiotic factors | part of an ecosystem that have never been living |
| habitat | the specific environment in which an organism lives in |
| resource | anything an organism needs |
| Population size | describes the number of individual organisms present in a given population at a given time |
| population density | describes the number of individuals within a population per unit |
| population distribution | describes how organisms are arranged within an area |
| Age structure | describes the relative numbers of each organisms of each age within a population. |
| age structure diagrams | visual tools scientists use to show the age structure of populations |
| sex ratio | a populations proportion of males to females |
| survivorship curves | to show how the likely hood of death varies with age |
| immigration | the arrival of individuals from outside a given area |
| emigration | the departure of individuals from a given area |
| migration | a seasonal movement into and out a given area |
| exponential growth | when a population grows by a fixed percentage every year |
| limiting factors | characteristics of the environment that limit population growth |
| carrying capacity | the largest population size a given environment can sustainably support |
| logistic growth | describes how a populations initial exponential increase is slowed and finally stopped by limiting factors |
| density dependent factor | the higher the population density the less food and water will be available per individual |
| density independent factor | limiting factors whose influence is not affected by population density |
| biotic potential | maximum ability to produce offspring in ideal conditions |