(Abstre:t ef e lecture given at U.C.LeA. ds a co Fhysics to tie Piolecical ond Vedical Sclerec:.} ve on “the f) plication of Nuclear Abest the enly point et which the three fields of genetics, mcdicine and + raviation acet is in the matter of mutation, 2 Litction retec in Lebrratery plents and -timals eve sagily altered by exposing chromocenes or thoir gorm cells to suitable doses a cf potietion, usueliv Nercys. Increases cf siverel thousend perecrt? ere usual, €ipesare ic bosb Fs Tne significanee of incressed mats tis retes in mor. sere highliznted by the a consijerable number of human beirgs to panca r:.diation folicwing the atozic eS cdesione st hiveshira and leg: o3ki. 7 .icus dire pr: icticns have been mode thet roustieis imueed br rediation reacesed by the cows detonet as would glter the genetic WelStee Of the Cowes Janarncas popatlstrom., ahhes coirup y 2fter the csecatind Jet Tho to tosecusdice Gese:r tial navollen: b-fore us fa cs uch thie 3> 2 coun be ka: 2 Lani dl Gin iaislte. of inhovivines; (2) tre cores el potere of the ec clusion cen be speed. ara: (i) to review briefly viution prouecs; end 3) the Mabnmer inwvin ch radivtion can atc, b.o gece le structure of a popgulction. Pron the stiondpeint of weeheaniea ve seve, for whe most part, thoce things to 0 he +3 nM oe we (li The neture of the gene and its mce sf accion. relationship of genes to chrorosenxns and th: crderly patterns they . a form in the chremecoie. (3) The behavior of hemolerous chronosones in ths zooces. cf sperm cnd ege formation and the existence ci carcmcsemes cf ev least two general types: thot the gene consists chiefly of nucleie ccit, possibly as anal a caertity es one molecule or less, oe Eor o>. ° ce i The gene is better kncwn for what it docs then for het it is, HH ce the sex chromcsozes or heterogom:s amithe other chromosemes or autosomes.