Why do bannanas ripen other fruit?
I have heard that if you put a banana in a bag with any other kind of fruit it would ripen the other fruit. Would it taste as good as a naturally ripened fruit?
The reason it ripens is because bananas happen to produce a huge amount of the ripening chemical that fruit uses, Ethylene. It's the same stuff that can be processed to create polyethylene - plastic. Bananas secrete loads of ethylene, and so it will spread to any other fruit in the fruit bowl. All fruit use ethylene as a signal to ripen, so this is a natural way to encourage fruit to ripen.
If you traumatise a plant, such as by pulling leaves off, it will release a burst of ethylene as a growth signal to the rest of the plant.