| A | B |
|---|
| population | a group of organisms, all of the same species, that live in a specific area |
| exponential growth | growth that means as a population get larger, it also grows at a faster rate; result in unchecked growth |
| J-shaped curve | exponential growth |
| S-shaped curve | growth that stabilized under the pressure of limiting factors |
| carrying capacity | the number of organisms of one species that an environment can support indefinitely |
| life-history pattern | an organism's reproductive pattern |
| rapid life-history pattern | organism reproduce rapidly, produce many offspring in a short time period, and have a short life span |
| slow life-history pattern | organisms that reproduce slowly, live in more stable environments, reproduce and mature slowly, and live long. Maintain population sizes at or near carrying capacity |
| density-dependent factors | The factors are disease, competition, predators, parasites, and food. These factors have an increasing effect as the population increases. |
| density-independent factors | These factors affect populations, regardless of their density. Most are abiotic factors like temperature, storms, etc. |
| predation | the term for predators consuming prey |
| organisms interactions | Population sizes are limitied not only by abiotic factors, but also by ____________ ___________ |
| effects of crowding and stress | aggression, descrease in parental care, decreased fertility, and decreased resistance to disease |
| demography | the study of human population size, density and distribution, movement, and its birth and death rates |
| birthrate | the numer of live births per 1000 population in a given year |
| death rate | the number of deaths per 1000 population in a given year |
| Population Growth Rate (PGR) | (Birthrate+immigration rate) - (Death rate + emigration rate) = ? |
| doubling time | the time neede for a population to double its size |
| age structure | the proportions of the population that are in different age levels |
| biodiversity | the variety of species in a specific area |
| extinction | the disappearance of a species when the last of its members dies |
| endangered species | species whose numbers become so low that extinction is possible |
| threatened species | a population of species that is likely to become endangered |
| threats to biodiversity | habitat loss, habitat fragmentation, edge effect, habitat degradation, water pollution, land pollution, exotic species |
| habitat fragmentation | the separation of wilderness areas from other wilderness areas |
| edge effects | the different conditions along the boundaries of an ecosystem |
| habitat degradation | the damage to a habitat by pollution |
| acid precipitation | rain, snow, sleet, and fog with low pH values |
| ozone layer | _________ _________absorbs some of the unltraviolet waves striking the atmosphere, reducing the ultraviolet radiation reaching the Earth's surface |
| exotic species | species that are not native to a particular area |
| conservation biology | is the study and implementation of methods to protect biodiversity |
| natural resources | those parts of teh environment that are useful or necessary for living organisms |
| US Endangered Species Act | Became a law in 1973 and make it illegal to harm any species on the endangered or threatened species list. |
| habitat corridors | protected strips of land that allow the migration of organisms from one wilderness territory to another |
| sustainable use | the philosophy that strives to enable people to use natural resources in ways that will benefit them and maintain the ecosystem |
| reintroduction programs | programs that release organisms into an area where the species once lived |
| captivity | an organism that is held by people |
