The term SIMPLE AQUATIC 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 microscopic single-celled organisms to large seaweeds. They are found in both freshwater and marine environments and play an important role in the food chain. Algae are also used in many industries, such as food production, pharmaceuticals, and biotechnology.