ABSTRACT
Mutation refer s t o an y chang e i n th e bas e sequenc e o f D N A tha t yield s a mutan t
phenotype. Mutation s ar e produce d b y th e replicatio n errors , th e deletio n a n d
insertion o f bases, th e covalen t modificatio n o f bases b y physica l agents (ionizin g
radiation an d ultraviole t light), an d by a variety of chemica l agents. M u c h of thi s
D N A damag e ca n be repaired , because th e appropriate genetic informatio n can be
recovered fro m th e undamage d D N A strand . We discusse d briefl y in Chapter 11
the repai r roles o f th e 3 ' — > 5' an d 5 ' — » 3' activitie s o f th e D N A polymerases .
