The use of any harmful organism (such as a bacterium or virus) as a weapon of war.

A biological pathogen or toxin designed or used for warfare.

(biology) Any of several mechanisms that regulate the periodicity of biological functions. / The progression from puberty to menopause during which a woman can bear children.

plural of biological clock

(psychology) The application of the principles of biology to the study of mental processes and behavior.

plural of biological weapon

plural of biological pump

(earth science) The collection of biological ocean processes that regulate the uptake, storage, and release of carbon.

plural of biological father

plural of biological mother