Bacteriofage waa koox caadi ah oo kala duwan oo fayrasyo ah waana hay'adda noolaha ugu badan ee deegaanka biyaha ah. Waxaa jira ilaa toban jeer in ka badan fayrasyadaas badaha marka loo eego bakteeriyada, oo gaareysa heerar 250,000,000 oo bakteeriyofage ah halkii mililitir ee biyaha badda. Fayrasyadaani waxay ku dhacaan bakteeriyada gaarka ah iyagoo ku xiraya molecules-ka soo-dhoweeyaha dusha sare ka dibna galaan unugyada. Muddo gaaban gudahood, xaaladaha qaarkood daqiiqado gudahood, polymerase bakteeriyada waxay bilaabayaan inay u turjumaan fayraska mRNA protein. Borotiinadaani waxay ku sii socdaan inay noqdaan virions cusub gudaha unugyada, borotiinada kaaliyaha, kuwaas oo ka caawiya isku soo ururinta virions cusub, ama borotiinada ku lug leh lysis cell. Enzymes-ka ayaa ka caawiya burburka unugyada unugyada, iyo kiiska T4, in ka badan toban daqiiqo gudahood ka dib markii ay jiraan in ka
bakteeriyada oo leh difaac la'aan cudurka