system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can they genetically engineer seedless fruits (like oranges, grapes, and watermelon), but not pitless fruits (like cherries, peaches, etc.)?
gpt
You'll notice with pitted fruits, the stem connecting the fruit is directly in contact with the seed pit and the fruit grows outwards from it. The pit becomes both the gate for nutrients and the scaffold for the rest of the fruit to grow.

In fruits with seedless varieties, the stem does not directly connect to the seeds. The seeds develop inside part of the fruit. Interrupting the seed production still allows the rest of the fruit to grow.