Which of the algae contains mannitol as reserve food material?
Ectocarpus
Gracilaria
Volvox
Ulothrix
Ectocarpus (Brown alga) has mannitol as reserve food material.
Ulothrix and Volvox belong to Chlorophyceae (green algae). Members of this class have starch as reserve food material.
Gracilaria is a red algae belonging to Rhodophyceae. It's stored food in the form of floridean starch