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 very different. There would be no trees or flowering plants, and most organisms would have no food because plants form the base of most food chains. The atmosphere would contain little or no oxygen, so most animals and humans could not survive. People would also lack many plant-based products, including building materials, medicines, fuels, and fibers. Fossil fuels would not have formed because they developed from ancient plant and organism remains.