Some seem to have confused EMPHASIZING certain areas as opposed to ISOLATING that area, which are two different concepts. In terms of emphasizing an area, yes it is possible or people would do one exercise for every muscle group (which works for some, e.g GVT, 5X5).
Arnold used BB curls for mass, Incline curls for mass, Concentration curls for Peak, Seated DB curls for Shape.
Lower biceps can be emphasized using preacher curls, upper biceps through peak contraction exercises (cable curls, crossover curls,etc), outer heads with close grip, inner head with wide grip.