Which part of brown algae is most important in photosynthesis?
Most macroalgae (multicellular algae) are made up of three
parts. The blade is a leaf-like structure that captures light and
carries on photosynthesis. The stipe is the stem of the algae. The
holdfast is the anchor for the algae; it holds the algae to a solid
surface such as a rock or pier. Although the holdfast may look like
roots, it does not function to get nutrients or water. Some algae
may have a fourth structure, the pneumatocyst; this structure is an
air bladder on the stipe or blade that functions to keep the algae
afloat in the water column.