Have you ever taken the time to contemplate just why bananas are indeed curved? Is it because of some issue with their genes that make them do this? Is it because that is just the way that they are intended to be in the same way as a pear is in the shape of a pear?
The answer is no to both of those options as it is a lot easier to understand than you may have initially expected. The real answer is because the banana grows towards the sun, but it doesn’t start out pointing in that direction. Instead, it starts growing slightly away from the sun and just like plants will lean in a particular direction to get the best light, the same can be said for the banana.
In other words, it has to do with nature, but not what you anticipated and the humble banana just wants the maximum amount of light to help it grow to the best of its ability.