An example of colonial alga is
1. Chlorella
2. Volvox
3. Ulothrix
4. Spirogyra
Which one of the following statements is wrong?
1. | Algae increase the level of dissolved oxygen in the immediate environment |
2. | Algin is obtained from red algae and carrageenan from brown algae |
3. | Agar-agar is obtained from Gelidium and Gracilaria |
4. | Laminaria and Sargassum are used as food |