Some of this stuff is BANANAS. (Sorry.)
Not all oranges are orange.
In sub-tropical growing regions (like Brazil, the country that grows the most oranges in the world) there are never temperatures cold enough to break down the chlorophyll in the fruit's skin, which means it may still be yellow or green even when it's ripe. But because American consumers can't fathom such a phenomenon, imported oranges get treated with ethylene gas to get rid of the chlorophyll and turn them orange.
This also means that Florida oranges tend to be yellower than California oranges, because they're grown further south.
Most commercial fruits are clones.
Which, when you actually look at supermarket displays of perfectly identical apples and oranges and peaches, isn't that shocking. Producers want specific varieties of fruit, called cultivars (say, Fuji apples or Bosc pears) to remain perfectly consistent, without all the unpredictable genetic mutations you get with old-fashioned sexual reproduction (pollinating flowers, planting seeds, and seeing what the heck comes up).
The clone tree armies are grown by grafting.
If you ate a Macintosh apple and planted the seed, the tree it grew would produce apples that looked and tasted nothing like Macintoshes. So, instead of planting seeds, growers attach a cutting from the genetically desirable tree onto an existing branch or sapling (called the "rootstock") so that the grafted bit produces apples genetically identical to those on the tree it was cut from. If you look closely at the tree in the photo, you can see that there are multiple types of apples on the different branches, all grafted onto one rootstock tree.
With seedless fruit, like some citrus, the necessity of grafting is even more extreme: Since the trees don't produce seeds (originally a genetic mutation that was noticed and propagated because it's so darn convenient), they're incapable of reproducing without being cloned by humans.
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