| A | B |
|---|
| decomposer | Any organism that feeds or obtains nutrients by breaking down organic matter from dead organisms. |
| density | Concentration of matter of an object; number of individuals in the same species that live in a given area; the mass per unit volume of a substance in a given area. |
| digestive system | The alimentary canal and digestive glands regarded as an integrated system responsible for the ingestion, digestion, and absorption of food. |
| dominant trait | A trait expressed preferentially over another trait. |
| ecosystem | All living and nonliving things in a biological community; their physical environment, including their interactions with each other. |
| element | Any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter. |
| energy pyramid | A diagram that shows the amount of energy that moves from one feeding level to another in a food web. |
| environment | The sum of conditions affecting an organism, including all living and nonliving things in an area, such as plants, animals, water, soil, weather, landforms, and air. |
| excretory system | The system which works on excretion (the process of eliminating waste products of metabolism and other non-useful materials). It is an essential process in all forms of life. |
| extinction | No longer in existence; no longer active; to cease to exist. |
| food chain | Transfer of energy through various stages as a result of feeding patterns of a series of organisms. |
| food web | The interconnected feeding relationships in a food chain found in particular place and time. |
| gas | One of the fundamental states of matter in which the molecules do not have a fixed volume or shape. |
| gene | A specific part of a chromosome or sequence of DNA that determines a particular feature or characteristic in an organism. |
| habitat | A place where animals find food and shelter. |
| herbivore | An animal that eats or obtains nutrients from plants, algae and other producers. |
| inherited trait | An inborn characteristic or behavior that is passed from parent to offspring; hereditary. |
| instinct | Inborn behavior or fixed action pattern that is unlearned and inherited. |
| learned behavior | A behavior that is taught or acquired over time or with experience. |
| life cycle | The entire sequence of events in an organism’s growth and development. |
