Please help on this as well

How does natural selection change thephenotypes within a population over time?

What is turgor pressure, what causes it, and what does it do for a plant?

Ronald wants to see if a new shower cleaner works better in removing soap than his old cleaner. he uses the new cleaner on one half of the shower tiles and his old cleaner on the other half. identify the independent and dependent variables in this experiment. enter your answer in the space provided.