| A | B |
|---|
| Population | all organisms of the same species that live in an area at the same time |
| Community | all the populations of all species that live in an area at the same time |
| Ecosystem | all the organisms living in an area and the nonliving parts of that environment |
| Biosphere | the part of Earth that supports life |
| Ecology | the study of interactions that occur among organisms and their environments |
| Dependence | rely on another for support |
| Environment | all surrounding things, conditions, and influences affecting the growth of living things |
| Food chain | a simple model of the feeding relationships and energy flow in an ecosystem |
| Food web | a model that shows all the possible feeding relationships among the organisms in a community; interlocking food chains |
| Matter | what all things are made up of; has mass and takes up space |
| Recycle | to process or treat something so that it can be used again |
| Sunlight | the source of most energy on Earth |
| Energy | the ability to do work |
| Relationships | connection; act of belonging |
| Terrestrial biomes | large geographic land areas that have similar climates and ecosystems |
| Aquatic ecosystems | places where organisms grow or live in water |
| Producer | organisms that use an outside energy source such as the Sun to make energy-rich molecules |
| Consumer | organisms that get energy by eating other organisms |
| Herbivore | consumers that eat only plants |
| Carnivore | consumers that eat only other animals |
| Omnivore | consumers that eat both plants and other animals |
| Decomposer | nature’s recyclers |
| Energy pyramid | a model that shows the amount of energy available at each feeding level |
| Limiting factors | anything that restricts the number of individuals in a population |
| Carrying capacity | the largest number of individuals of one species that an ecosystem can support over time |
| Competition | one or more organisms, populations, or communities attempting to use the same resource |
| Predation | the act of being involved in a predator/prey relationship |
| Predator | consumer that captures and eats other consumers |
| Prey | the organism that is captured by the predator |
| Symbiosis | a close, long-term relationship between species |
| Mutualism | a symbiotic relationship in which both organisms benefit |
| Commensalism | a symbiotic relationship in which one organism benefits and the other is not affected |
| Parasitism | a symbiotic relationship in which one organism benefits and the other is harmed |
| Parasite | an organism that lives in or on another organism and causes it harm |
| Host | a living plant or animal in or on which a parasite lives |
| Adaptation | any variation that makes an organism better suited to its environment |
| Tundra | a cold, dry, treeless biome that gets little precipitation and is covered with ice most of the year |
| Tropical rainforest | biome with warm temperatures, wet weather, and dense plant growth |
| Temperate deciduous forest | the biome we live in; biome with four seasons and climax forests of trees that lose their leaves in autumn |
| Savanna | a grassland that often has scattered trees and that is found in tropical areas where seasonal rains, fires, and drought happen |
| Desert | dry biome with extreme hot and cold temperatures |
| Taiga (Coniferous forest) | biome with long, cold winters, moderate precipitation, and forests of evergreen trees |
| Grassland | biome of temperate and tropical regions that receive little precipitation and are made up of climax communities of grasses |
| Freshwater | aquatic ecosystems including lakes, ponds, wetlands, rivers, and streams |
| Marine | aquatic ecosystems including oceans and seas that contain high levels of salt |
| Estuary | the area where a river meets the ocean and contains a mixture of salt and fresh water called brackish water |
| Habitat | the place in which an organism lives |
| Niche | an organism’s role in its environment; how it obtains food and shelter, finds a mate, cares for its young, and avoids danger |
| Succession | a series of predictable changes that occur in a community over time |
| Primary Succession | a series of changes that occur in an area where no soil or organisms exist |
| Secondary Succession | the series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist |
| Climax Community | a community of plants that is relatively stable and undisturbed |
| Pioneer species | the first species to populate an area |
| Biotic Potential | the highest possible rate of growth for a population |
| Natural Selection | a theory that states that organisms with traits that are best suited to their environment are most likely to survive and reproduce |
