| A | B |
|---|
| barrier | something that stops migration from one area to another |
| behavior | the way an organism acts toward its ecosystem |
| competition | the process of one organism working against another to get something it needs to survive |
| migration | the moving of organisms from one place to another where there is more room and resources |
| niche | the role of an organism in a community |
| algae | plantlike organisms that live in water and get their energy from the sun |
| coral reef | an underwater ridge or mound made by colonies of tiny coral animals |
| desert | a sandy or rocky land area with little precipitation and little plant life |
| nocturnal | mostly active at night |
| urban | located in the city |
| conservation | saving, protecting or using something wisely, without wasting it |
| overpopulation | too many of at least one kind of living thing in an area compared to the available resources |
| pollution | the adding of harmful substances to water, air or land |
| succession | the process by which new plant and animal populations replace old plant and animal populations over time |
| community | the living things in an ecosystem |
| ecosystem | all the living and nonliving things in an environment and all their interactions |
| habitat | the home of an organism |
| population | all the members of a single type of organism living in a certain type of area |
| chlorophyll | a substance in plants that gives them their green color and helps make food by trapping the suns energy |
| photosynthesis | a process that uses energy from sunlight to change water and carbon dioxide into food |
| consumer | any animal that eats plants or eats other plant-eating animals |
| decomposer | an organism that breaks down wastes and the remains of other organisms |
| nutrient | a substance used by organisms for energy, growth, and maintenance |
| producer | an organism, such as a plant, that makes its own food |
| carnivore | a consumer that eats only animals |
| food chain | the path of the energy in food being transferred from one organism to another |
| food web | the pattern that shows how food chains are related |
| herbivore | an animal that eats plants |
| predator | an animal that hunts other animals for food |
| prey | a living thing that is hunted for food |
