The term 'Simple Marine Plant' can be summarized as an ALGA, which is a four letter word. Algae are a large and diverse group of aquatic organisms that range from single-celled microorganisms to large multicellular forms. They are found in both freshwater and marine environments, and are capable of photosynthesis. Algae are an important part of the food chain, providing food for many aquatic animals. They also play an important role in the global carbon cycle, as they absorb carbon dioxide and release oxygen into the atmosphere.