To simply confirm what has already has been said...
In this case two significant individuals come to mind, Larry Scott, Arnold Schwarzenegger and Albert Beckles.
If you look at Larry's arms when he was at his peak you would notice that they are full and long but lacking any real "peak", conversely Arnold's arm had both length and height and to complete the comparison Albert has all the "peak" one could ever ask for but has a complete lack of length. Does this make them any less of a completive bodybuilder... absolutely not, each have stream of titles and each are a legend in the sport.
Now, as far as exercises are concerned the ones that seem to add greater height would be the following:
~ Standing or Seated Concentration Curls
~ Lying Dumbbell Curls
~ Two-handed Cable Curls
These will add as much to the height of the biceps but in the end, as has been stated above in other posts... genetics is the limiting factor, some have it and some just never will; however, I am sure that as you develop and grow you will learn of a body-part that you can develop and shape far better than someone else so that perhaps you can exploit it... Tom Platz had his amazing legs; Larry Scott had almost perfect arms and the list goes on. My friend, may training be good and life be better.
Good growing and terrific training!!!!
Maxmuscle66