Q.The reserve food of Rhodophyceae is:

Rhodophyceae (red algae) store food reserves as Floridean starch, a glycogen-like polysaccharide.

Different algal classes store carbohydrate reserves in chemically distinct forms, which is itself a useful taxonomic character:

• Chlorophyceae (green algae) store starch (true starch, similar to that of higher plants), typically within the chloroplast (around pyrenoids).
• Phaeophyceae (brown algae) store laminarin (and mannitol as a soluble reserve). …

Rhodophyceae (red algae) store their reserve food as floridean starch, a starch-like polysaccharide structurally similar to glycogen.

Each major class of algae is characterised by a specific pigment composition and a specific stored food reserve, which are used to classify them:

• Chlorophyceae (green algae) store ordinary starch inside chloroplasts (pyrenoids).
• Rhodophyceae (red algae) store floridean starch, which resembles amylopectin/glycogen in structure and is deposited outside the chloroplast in the cytoplasm.
• Cyanophyceae (blue-green algae, which are actually prokaryotic) store cyanophycean starch (glycogen-like) and cyanophycin granules. …