01	Biochemistry	Chemical reactions and properties of biochemical compounds; Analytical methods and identification of biochemical substances; Biochemical assay and analysis. For physiological effects of drugs, See 06/15, Pharmacology. See also 06/11, Toxicology. For the biological warfare applications of biochemistry, See 15/06/03, Chemical, Biological and Radiological Warfare.
02	Genetic Engineering and Molecular Biology	Intentional production of new genes and alteration of genomes by the modification of new genetic material; Use of chemistry and physics to study biological phenomena on the molecular level; Structure and function of biological macromolecules such as proteins and nucleic acids. For genetic and heredity studies, See 06/03, Biology.
03	Biology	Biological topics not included in other groups such as botany, zoology, animal behavior, heredity, genetics, and evolution; Reproduction and development; Morphology; Taxonomy, classification and nomenclature. For anatomy and physiology, See 06/04, Anatomy and Physiology. For aquatic plants and animals in ocean or sea water, See 08/01, Biological Oceanography. For the care and breeding of laboratory animals, See 02/05, Animal Husbandry and Veterinary Medicine. For genetic engineering, See 06/02, Genetic Engineering and Molecular Biology. For studies of animal behavior under experimental conditions, See 05/08, Psychology.
04	Anatomy and Physiology	The study of the functions of cells, tissues, organs and systems in humans and animals by physical and chemical methods; Growth; Aging; Metabolism; Biological rhythm; Healing and repair; Sensation; Respiration; Electrophysiology; Neuroanatomy. For physiological psychology, See 06/10, Stress Physiology.
05	Medicine and Medical Research	Prevention, diagnosis and therapy of diseases; Internal medicine; Pediatrics; Geriatrics; Dermatology; Opthalmology; Psychiatry; Dentistry; Nuclear medicine; Experimental medicine; Public health; Medical and paramedical training; Paramedical services. Includes nursing, first aid, medical technology, physical therapy and prosthesis. For pharmaceutics, See 06/15, Pharmacology. For veterinary medicine, See 02/05, Animal Husbandry and Veterinary Medicine. For industrial medicine, See 24/07, Environmental Health and Safety.
06	Ecology	Interrelations of organisms and their environment; Ecosystems; Food chains; Adaptation; Ecological succession; Biogeography. For the effects of pollution on the environment, See Field 24, Environmental Pollution and Control.
07	Radiobiology	Radiation biology; Interaction of biological systems with ionizing electromagnetic and particle radiation; Dosimetry; Health physics; Radiation injury; Infrared burns; Nuclear radiation sickness and injury. For radiology and radiotherapy, See 06/05, Medicine and Medical Research.
08	Food, Food Service and Nutrition	Processing, packaging, storage, preparation and dispensing of food; Kitchen and cooking equipment; Dietetics; Food bacterial count; Calorie count; Food chemistry.
09	Hygiene and Sanitation	Personal hygiene. For sewage treatment, See 24/04, Water Pollution and Control.
10	Stress Physiology	Effects of extreme environments or unusual stimulation on biological processes; Acclimatization; Physiological effects of motion, gravity, sound, light, heat, magnetism, sensory deprivation, fatigue, weightlessness, cold and altitude. Includes air, space and underwater environments. For effects of ionizing electromagnetic and particle radiation, see 06/07, Radiobiology.
11	Toxicology	Study of the adverse effects of substances on biological systems and the diagnosis and treatment of toxic diseases; Toxicity studies; Antidotes. See also 15/06/03, Chemical, Biological and Radiological Warfare.
12	Medical Facilities, Equipment and Suplies	Medical facilities such as civilian and military hospitals and clinics; Equipment and supplies for hospital, laboratory and field use. For equipment and techniques for sustaining life in adverse environments, See 23/05, Life Support Systems. For bioinstrumentation, See 23/01, Biomedical Instrumentation and Bioengineering. For veterinary facilities, See 02/05, Animal Husbandry and Veterinary Medicine.
13	Microbiology	Studies of microscopic plants and animals, bacteria, viruses and rickettsia. See also 08/01, Biological Oceanography, and 15/06/03, Chemical, Biological and Radiological Warfare.
14	Weapons Effects (Biological)	Wound ballistic studies; Wounds, injuries or other conditions directly resulting from weapons. For effects of CBR weapons, See 15/06/03, Chemical, Biological and Radiological Warfare. For the physiological effects of nuclear weapons, See 06/07, Radiobiology. For the nondiological effects of nuclear weapons, See 19/11, Nuclear Weapons. For the nondiological effects of conventional weapons, See 19/09, Explosions, and 19/10, Ballistics. For the medical treatment of wounds and injuries, See 06/05, Medicine and Medical Research.
15	Pharmacology	The synthesis, composition, properties and physiological effects of drugs. Includes psychopharmacology. See also 15/06/03, Chemical, Biological and Radiological Warfare.