Write a paragraph describing how Earth would be different if photosynthetic plants had not evolved.

Answer:

If photosynthetic plants had not evolved, Earth would be a completely different and likely uninhabitable planet for most modern life forms. Because photosynthesis is the primary process that releases oxygen into the atmosphere, there would be very little oxygen for aerobic organisms to breathe. Furthermore, plants serve as the foundation of almost every food chain; without them, there would be no food for herbivores or the carnivores that eat them. Additionally, we would lack essential materials derived from plants, such as timber for building, fibers for clothing, many medicines, and even fossil fuels, which are formed from the remains of prehistoric photosynthetic organisms.