What is the factor that changes in a controlled experiment

Which of these correctly describes the difference between processes that take place in prokaryotic and eukaryotic cells?

Which of the following molecules could pass through the plasma membrane by simple diffusion? a. na+ ions b. glucose c. amino acids d. carbon dioxide

Select all the correct answers. which statements fail to meet the requirements of a scientific claim? a). in the final 100 meters of a 10,000-meter race, an athlete's speed is more strongly related to anaerobic efficiency than to aerobic efficiency. b). flowers that reflect the most ultraviolet light are more likely to attract bees and other pollinators than flowers that reflect less ultraviolet light. c). the evidence supporting newton's laws of motion was accurate in newton's time, but the universe operates differently today. d). even though evidence indicates that the solar system's planets follow elliptical paths, copernicus's model involving circular orbits is true.