Cross section of different areas of the same plant show cells with very different structure. what does this tell you about the different areas?

How do you date a sample of rock that you suspect as being one of the earliest on earth

In many humans, exposing the skin to sunlight over prolonged periods of time results in the production of more pigment by the skin cells (tanning). this change in skin color provides evidence that -

What processes would you expect to be key in the production of yogurt ?