What is the structure and function of a phaeophyta?

Phaeophyta, or brown algae, have a multicellular structure with a holdfast for anchoring, a stipe for support, and blades for photosynthesis. They contain chlorophyll a and c, as well as fucoxanthin, giving them their characteristic brown color. Brown algae play an important role in marine ecosystems by providing habitat for various organisms and serving as a food source for marine animals.