Are biceps and triceps exercises necessary for basketball training?

Biceps and triceps, as all major muscle groups in the body, are important for basketball but they do not necessarily need to be worked out in isolation.

There are several exercises that can be done to integrate the upper arm into resistance programs such as pushing (Bench Press or Push Up) and pulling exercises (Row or Pull Up). The pushing exercises will incorporate the triceps and the pulling movements will incorporate the biceps.

There are other compound movements that can also be done that integrate an isolated bicep exercise within other movements. An example of this would be a Lunge, Curl, and Press. To perform this exercise:
Stand holding dumbbells at your side
Lunge forward reaching the dumbbells towards your front foot
As you stand up perform a bicep curl bringing the dumbbells to your chest
Once standing press your arms overhead

Remember however, in the interest of looking good in your basketball jersey biceps and triceps are a must to work out on photo day...an old joke in the weight room.

Biceps and triceps exercises are fine, but can take more time than they are worth.  Your biceps and triceps get plenty of work when performing pushing and pulling exercises.  Further, there is no such thing as a single joint isolated movement in sport.  Adding arm exercises to your routine may increase the size of your arms (although this increase is minimal when pushing and pulling movements are already incorporated in the routine), but it is not likely that it will have an effect on your basketball performance.