Explanation

Like plants, algae have cell walls which contain either polysaccharides such as cellulose (glucan) or a variety of glycoproteins or both. The inclusion of additional polysaccharides in algal cell walls is used as a feature for algal taxonomy. Mannans form microfibrils in the cell walls of a number of marine green algae including those from the genera $Codium,\ Acetabularia$ as well as in the walls of some red algae like $Porphyra.$