Introduction to Plants

Introduction to Plants:

Plants are critical to other life on this planet because they form the basis of all food webs. Most plants are auto trophic, creating their own food using water, carbon dioxide, and light through a process called photosynthesis. Some of the earliest fossils found have been aged at 3.8 billion years. These fossil deposits show evidence of photosynthesis, so plants, or the plant-like ancestors of plants, have lived on this planet longer that most other groups of organisms. At one time, anything that was green and that wasn’t an animal was considered to be a plant. Now, what were once considered “plants” are divided into several kingdoms: Protista, Fungi, and Plantae. Most aquatic plants occur in the kingdoms Plantae and Protista.
Photosynthesis - Page 1
6CO₂ + 12H₂O -----> C₆H₁₂O₆ (glucose) + 6H₂O + 6O₂ Photosynthesis is the process by which plants convert light, carbon dioxide and water into food, or energy. It is extremely important for the majority of life on earth because plants convert inorganic (unuseable) carbon into an organic (useable) form. Most of the carbon found on earth is in an inorganic form, such as carbon dioxide (CO₂), bicarbonate (HCO₃^-) and carbonate (CO₃^-2). Plants alter the carbon found in these compounds and store it as organic carbon compounds. Aquatic plants are especially important in this process because they account for 40% of the photosynthesis on the planet, though they are less than 1% of the plant biomass.