Plants and Humans Plants, one of the six taxonomic Kingdoms of different life forms generally accepted throughout the United States, play an important role in the existence of other life forms such as animals. In fact, plants are so important for life on planet Earth that humans could not exist without plants. Photosynthesis, the process by which plants convert sunlight and carbon dioxide into oxygen and water, is responsible for the creation of the Earth's atmosphere; and the life forms that have evolved in it. In addition to creating the environment, plants also maintain that environment by constantly converting carbon dioxide into the oxygen necessary for human survival. Plants also provide the food that is necessary for humans to survive, as well as providing the basis for the survival of other species that are also essential to human survival. In short, plants are indispensable to the human race and people could not have evolved, and could not survive if there were no plants.

The main role plants play in the survival...

The oxygen that humans breathe in their air comes from plants, through a process called photosynthesis. Plants use sunlight as the energy source for a complex system of chemical processes which convert water and carbon dioxide from the atmosphere into oxygen and organic compounds such as sugars, carbohydrates, lipids, proteins, and nucleic acids. (Ke, 2003, p.1) The oxygen is released into the atmosphere to provide the air which animals, including humans, need to breathe. Through a process called "respiration," humans then convert the oxygen and organic compounds back into carbon dioxide which is released back into the atmosphere where plants can start the cycle again.
After being the mechanism for the conversion of sunlight into organic energy through photosynthesis, the next most important duty plants play…