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biological warfare

(Encyclopedia)biological warfare, employment in war of microorganisms to injure or destroy people, animals, or crops; also called germ or bacteriological warfare. Limited attempts have been made in the past to spre...

warfare

(Encyclopedia)warfare, violent conflict between armed enemies. In modern times warfare has usually been conducted by the armed forces (e.g., army, navy, and air force) of a nation or other politically organized gro...

germ warfare

(Encyclopedia)germ warfare: see biological warfare. ...

chemical warfare

(Encyclopedia)chemical warfare, employment in war of incendiaries, poison gases, and other chemical substances. Ancient armies attacking or defending fortified cities threw burning oil and fireballs. A primitive ty...

plasma, biological

(Encyclopedia)plasma, biological: see blood.

rhythm, biological

(Encyclopedia)rhythm, biological, or biorhythm, cyclic pattern of physiological changes or changes in activity in living organisms, most often synchronized with daily, monthly, or annual cyclical changes in the env...

nomenclature, biological

(Encyclopedia)nomenclature, biological: see classification. ...

symmetry, biological

(Encyclopedia)symmetry, biological, similarity or balance between parts of an organism so that when a straight cut is made through a point or along a line, equal, mirror-image halves are formed. Symmetry in body sh...

biological clock

(Encyclopedia)biological clock: see rhythm, biological. ...

biological diversity

(Encyclopedia)biological diversity or biodiversity, the number of species in a given habitat. Scientists have variously estimated that there are from 3 to 30 million extant species, of which 2.5 million have been c...