The first Jurassic Park movie was the 2nd best in my opinion. A guy named John Hammond found dinosaur DNA in a misquito. He used frog DNA to complete the code. The scientists there made all the dinosaurs female so they were not that agressive and could not breed. The frogs that they used could change their gender and that's how they started to breed. One guy shut down the security and all the dinosaurs got loose. That is why they decided no to open the park.