Modern algae are decendents of early photosynthetic eukaryotes which began to appear on the Earth over 1.5 million years ago. Algae are classified into six divisions based on their photosynthetic pigments, reserve food supply, and cell wall composition. In these six divisions of algae, three groups are multicellular and three groups are unicellular. Unicellular forms of algae include diatoms, euglenoids, diatoms, dinoflagellates, and many forms of green algae and they form plankton, a major food source for many aquatic animals. Multicellular algae, including, brown algae, red algae, and some green algae form common marine seaweeds. Green algae include vast degree of complex
             forms; unicellular organism; colonies; multicellular forms, which nuclear division is not followed by cytokinesis and the formation of cell walls; and multicellular forms, which have filaments, sheets, or a three-dimensional body. Some green algae have life cycles which alternate between haploid and diploid form. This is known as gametophyte and sporophyte. Because this life cycle is found in plants and plants share biochemical similarities with some green algae, it provides evidence that plants evolved from green algae.
             I. Algae: Are unicellular or multicellular eukaryotic photosynthetic organisms lacking muliticellular sex organs. All algae have chrolophyll a is a photosynthetic pigment.
             A. Unicellular Algae: Each cell is self-suffucient and needs only light, mineral from the surrounding water, and carbon dioxide to carry it life processes.
             i.e. Plankton are unicellular algae joined with invertebrate animals and immature
             forms of larger animals. The algae of plankton are known as photoplankton and
             they supply the atmosphere with large amounts of oxygen and a food source to
             B. Multicellular Algae: Live along shores and shallow waters. Have adapted to live in the conditions of the coastal
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