A [[chemical]] that kills or reduces the reproduction rates of organisms.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> Such chemicals may be secreted by living organisms (such as [[penicillin]], which is produced by certain molds) or they may be artificially synthesized. | A [[chemical]] that kills or reduces the reproduction rates of organisms.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> Such chemicals may be secreted by living organisms (such as [[penicillin]], which is produced by certain molds) or they may be artificially synthesized. |