| A | B |
|---|
| birth rate | The number of births in a population in a certain amount of time. |
| death rate | The number of deaths in a population in a certain amount of time. |
| immigration | Moving into a population. |
| emigration | Leaving a population. |
| population density | The number of individuals in an area of a specific size. |
| limiting factor | An environmental factor that prevents a population from increasing. |
| carrying capacity | The largest population that an area can support. |
| direct observation | Counting every member of a population. |
| indirect observation | Counting signs of organisms to estimate population size. |
| sampling | Counting the number of organisms in a small area (sample) and then multiplying over the larger area to estimate population size. |
| mark and recapture studies | Method used to estimate population size by capturing animals, marking them, releasing them, and then recapturing them. |
| examples of limiting factors | Food, water, space, and weather conditions. |
| habitat | The environment which provides an organism with what it needs to survive. |
| species | A group of organisms that can mate with each other and produce offspring that can also mate and reproduce. |
| Ecology | The study of how living things interact with each other and with their environment. |
| 4 levels of ecological organization | organism, population, community, ecosystem. |
| organism | A single living thing. |
| population | A particular species living in the same place |
| community | All of the populations in the same area that interact together. |
| ecosystem | The community plus the abiotic factors they interact with. |
