What are seeds? They are the babies of the plant.

What is fruit? It's how the plant disperses its seeds.

What is a seedless fruit plant? Sterile. It can't distribute its babies.

How do you make more seedless fruit plants? You clone them.

What is the disadvantage of clones? They don't change.

What happens to plants that don't change? Something that does change evolves to exploit them.

Yes, all naval orange plants are clones.