system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it that oranges are grown "pre-sliced" by nature? Why does this happen and also does any other fruit do this?
gpt
Trees make other trees by dropping seed.  Not many seed live to grow up to be big new trees, so the tree wants to give the seed it drops the best chance possible of living.

So firstly the tree needs to get the seed away from other seeds as much as practical as you've never seen trees grow right next to each other, have you?  They take each others water and things, big mistake.   Hence it grows the seeds all over the tree so they drop all over the place.  Some of them, if they can manage it, even make the seeds so light the wind will carry them away, or nice and tasty but difficult to digest so birds will eat them and then poop them miles away which is a good thing - but not in the case of oranges.  

Anyway, when a seed drops away from its mum tree, it is useful to have something to feed on when its a really little baby tree - just like a chick in the egg gets to eat the white stuff in an egg before it's ready to come out and say hello to the world.  A seed gets to eat the rotting orange material that is round it for a while to give it a good easy start in life.

So, as the orange rots, the segments tend to break away from each other, and each little seed or two is away from other seeds and gets it's own individual source of early yummy food so quite a lot of them actually survive.     

The same reason there is only 1 chick in each egg .. think of it that way.

Extra fact:  Oranges, like most fruit with seeds in, are round.  Why?  By fluke?  Coincidence?  Nope - because round things roll a bit especially if mum tree was on a hill.  So when they drop, they may roll away a little especially if the wind is high (which is when these things tend to drop off the trees) which is exactly what the mum tree wants and needs.  You don't see square fruit because they're no good at rolling!