Where do apples come from? Simple question, right? A farmer plants an apple seed, the seed grows into a tree, and the tree makes apples.
Where do seedless grapes come from? Well, the farmer plants-wait a minute! How DO they grow new seedless grapes?
Many plants have two ways they can reproduce. They can either make seeds, or they can reproduce vegetatively, by growing a new clone plant from a cutting of the original.
The first seedless grape vine appeared thousands of years ago in the Middle East, the result of a random genetic mutation. At this time, grapes were cultivated for wine and raisins. This new seedless grape vine must have caused quite a sensation, because soon lots of people were growing seedless grape vines from cuttings of the original, then handing out new cuttings themselves. The Thompson seedless grapes in your local produce section are all clones of this one, original genetic mutation.
You might be surprised to learn that the apples about are also clones. When a plant makes a seed, it generally cross-pollinates with another plant of the same species. Just like a child, this seed will have only half the genes of the each parent. If you planted the seed from your favorite type of apple, the new tree's fruit wouldn't taste exactly like the one you started with.
Customers tend to demand uniformity in the products they buy. As a result, almost all the fruit in your produce section are clones, grown vegetatively, not from seeds.