| abiogenesis |
the production of living organisms from nonliving matter; spontaneous generation. |
| abiotic |
characterized by an absence of living organisms; without life. |
| acquired characteristic |
a change in the structure or function of a living organism that is caused by environmental factors and may not be transmitted genetically. |
| ADP |
a biochemical compound involved in the storing and releasing of energy in all living cells; adenosine diphosphate. (Cf. ATP.) |
| aerobic |
occurring or living only in the presence of oxygen. [1/3 definitions] |
| ahimsa |
(Sanskrit) the principle of nonviolence based on the belief in the sacredness of all living creatures, as held by Buddhists, Hindus, and others. |
| air chamber |
a compartment in which air is confined for a special use, as in a pump, a hydraulic fluid regulator, or a living organism. |
| air mattress |
a mattress filled with air, used esp. for camping, mobile living, or as an extra bed for visitors. |
| air sac |
an air-filled space or cavity in a living organism, esp. any of the ends of certain bronchial tubes in a bird's body that connect with the larger body cavity and assist in breathing. |
| ala |
a wing or winglike part or structure on a living organism. |
| Algonquin |
any of several Algonquian Indian tribes formerly living in the region of southern Canada and the St. Lawrence River, or a member of one of these tribes. [1/3 definitions] |
| alien |
a living being from another planet or other place in the universe; extraterrestrial. [1/6 definitions] |
| alive |
having life; living. [2/4 definitions] |
| allogenic |
caused by environmental factors that do not involve living organisms. [1/2 definitions] |
| allopatric |
living in different geographic areas or in isolation, used esp. in reference to closely related species or to different populations of a single species. [1/2 definitions] |
| Alpine |
(l.c.) of, like, living in, or characteristic of high mountains or mountain regions above the timberline. [2/4 definitions] |
| Amish |
a Christian sect that separated from the Mennonites in the seventeenth century, the members of which advocate simple living and now live mostly in farming areas of the northeastern United States. [1/3 definitions] |
| anabolism |
the process in living organisms by which complex structures are synthesized from simple ones, as body tissues from food. |
| anaerobe |
any of various microorganisms, such as certain bacteria, that are capable of living without air or oxygen. |
| animal |
a living creature that is generally distinguished from plants by its cellular structure and by the ability to move voluntarily. [2/5 definitions] |
| animate |
alive; living. [1/9 definitions] |