| A | B |
|---|
| Parasitism | One organism benefits from the relationship, but the other gets no benefit and often suffers. |
| Commensalism | One organism benefits without harming or helping the other. |
| Trophic level | Each of the steps in a feeding relationship. |
| Predation | One animal species called the predator feeds on another animal species called prey. |
| Symbiosis | Describes interdependent relationships between species. |
| Mutualism | Describes interactions where both organisms benefit. |
| Nutrients | Elements and compounds that organisims need to carry out their life functions. |
| Ecology | The study of the interactions among living things and their environment. |
| Environment | Combination of physical and biological factors that affect the organism. |
| Abiotic factor | Physical factors that are not alive. |
| Biotic favor | Biological factors that are alive. |
| Ecosystem | Describes a collection of organisms and their relationships with the biotic and abiotic factors that affect their lives. |
| Population | All of the members of the same species that inhabit a specific area. |
| Renewable resource` | Resource that can be replaced. |
| Nonrenewable resource | Resource that can not be replaced. |
| Pollution | Substances that cause a harmful change in the air, water, or land. |
| Carrying capacity | The number of individuals that an ecosystem can support over time. |
| Biodiversity | Number of different species that live in an ecosystem. |
