system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Where do you get the seeds to grow seedless watermelons?
gpt
In a lot of seedless plants, you don't use seeds. You can propagate plants lots of other ways. Cuttings for instance. 

However, in seedless watermelons, seeds actually are used. The seedless variety is a 'triploid' plant (3 sets of chromosomes), which can't produce viable seeds. It is produced by hybridizing diploid and tetraploid varieties of watermelon.