Applications for DNA Extraction

[NotEntirelySure]

Hi! So I just learned how to extract DNA from strawberries in bio (HL) and thought it might be interesting to find a way to use it in another experiment (or possible IA). Does anyone have any suggestions for IA topics or just for any ways to apply DNA extraction for use in something else? (just for fun ) If possible I'd like to stay away from something like "which food gives the most DNA" (booooring). I also found a DIY gel electrophoresis thing but I'd have to buy a lot of potentially expensive supplies...  (although I imagine that's probably kinda inevitable for most of these kinds of experiments?)

Thank you!