Banana "trees" are actually herbs (plants lacking woody tissue) and the bananas are actually berries.
The banana plantations are the largest importer of the growth hormone gibberilic acid, which allows the plants to flower and produce fruits long before they would naturally.
Bananas also tend to heavily sprayed, so it is a good idea to rinse the outside or spray them with peroxide to get rid of the residues. People often make the mistake of peeling the banana then holding the fruit in their hands that just handled the sprayed skin transferring the spray residue to the fruit.