Plants are fascinating for many reasons, but especially because they produce their own food. When your plants absorb water, light, and carbon dioxide from the air, the plant creates glucose. Plants are called autotrophs, and creating glucose is how they feed themselves. They release oxygen into the air when they absorb these nutrients, which is a process called photosynthesis! Photosynthesis allows for plants to grow, and also keeps the Earth healthy by creating oxygen for creatures to breathe.