Unless you got insanely good genetics that cause your arms to grow just by lifting a pencil then no you don't need to work your biceps. Take it from someone who's been in the game for years, YOU NEED TO WORK ALL YOUR BODY PARTS TO GROW. And do NOT negelect your legs, for one thing squats will make your whole damn body grow.
You can detect right away those that are going to be shaky, and that will fall behind and those that are very hungry, and that hunger you will have to develop. You gotta create a goal for yourself whatever that may be, a short term goal and a long term goal and you gotta go after that. And if you donít see it, and if you donít believe it, who else will?