Biology :: Biology

Biology is the science of living systems. It is inherently interdisciplinary, requiring knowledge of the physical sciences and mathematics, although specialities may be oriented toward a congregation oforganisms or a level of organization. BOTANY isconcerned with plant life, ZOOLOGY with animallife, algology with ALGAE, MYCOLOGY withfungi, MICROBIOLOGY with microorganismssuch as protozoa and bacteria, CYTOLOGY withCELLS, and so on. All biological specialties,however, argon concerned with life and itscharacteristics. These characteristics includecellular organization, METABOLISM, responseto stimuli, development and growth, andreproduction. Furthermore, the informationneeded to control the expression of suchcharacteristics is contained within each organism.FUNDAMENTAL DISCIPLINES vitality is dividedinto many levels of organization--atoms,molecules, cells, tissues, organs, organ systems,organisms, and populations. The basic disciplinesof biology may study life at one or more of these levels. Taxonomy attempts to arrange organisms in immanent groups based on common features. It isconcerned with the identification, naming, andclassification of organisms. The seven majortaxonomic categories, or taxa, employ inclassification are kingdom, phylum, class, order,family, genus, and species. Early systems usedonly two kingdoms, plant and animal, whereasmost modern systems use five MONERA(BACTERIA and BLUE-GREEN ALGAE),PROTISTA (PROTOZOA and the otherALGAE), FUNGI, PLANT, and ANIMAL. Thediscipline of ECOLOGY is concerned with theinterrelationships of organisms, twain amongthemselves and between them and theirenvironment. Studies of the energy flow throughcommunities of organisms and of the environment(the ecosystem approach) are especially valuablein assessing the effects of human activities. Anecologist must be knowledgeable in otherdisciplines of biology. Organisms respond tostimuli from other organisms and from theenvironment behaviorists are concerned withthese respo nses. Most of them study animals--asindividuals, groups, or entire species--in describingANIMAL BEHAVIOR patterns. These patternsinclude ANIMAL MIGRATION, causa andmating, social organization, TERRITORIALITY,INSTINCT, and learning. When humans areincluded, biology overlaps with psychology andsociology. Growth and orientation responses ofplants can also be studied in the discipline ofbehavior, although they are traditionallyconsidered as belonging under development andPHYSIOLOGY, respectively. Descriptive andcomparative EMBRYOLOGY are the classicareas of DEVELOPMENT studies, althoughpostembryological development, particularly theaging process, is also examined. The biochemicaland biophysical mechanisms that control dominiondevelopment are of particular interest when theyare related to birth defects, cancer, and otherabnormalities. Inheritance of physical andbiochemical characteristics, and the variations thatappear from generation to generation, are the ecumenical subjects of GENET ICS. The emphasismay be on improving domestic plants and animalsthrough controlled breeding, or it may be on themore fundamental questions of molecular andcellular mechanisms of HEREDITY. A branch ofbiology growing in importance since the 1940s,molecular biology essentially developed out ofgenetics and biochemistry. It seeks to explainbiological events by studying the molecules within