Which of the following algae contains mannitol as reserve food material?
- Ulothrix
- Ectocarpus
- Gracilaria
- Volvox
Answer
(2) Ectocarpus
Solution
As per NCERT, the food in brown algae (Phaeophyceae) is stored as complex carbohydrates, which may be in the form of laminarin or mannitol.
Ectocarpus is a brown alga, so it stores mannitol.
Ulothrix and Volvox are green algae (store starch) and Gracilaria is a red alga (stores floridean starch).
Answer: (2)