Erlend, imagine if you were peeling away leaves and leaf bases from the pseudostem. Eventually, you would get down to a small nub in the center, just above the corm. That will be your apical meristem. On a more mature corm, you can use the lateral meristems that have formed, but haven't yet started to grow. This way, you don't sacrifice an entire plant. Good luck with it! I just had my first TC lab at school yesterday. African Violets and Crotons
. Oh well! Bananas are next...