A scientist is developing a potential treatment for cancer. She grows cells in hundreds of petri dishes and exposes the dishes to environments that are known to cause cancer. After exposure, the scientist determines that some of the petri dishes have cancer cells. What factor do all the petri dishes that contain cancer cells have in common?

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.