Eduprobe
Question:
Which one of the following statements is wrong?
Agar-agar is obtained from Gelidium and Gracilaria.
Laminaria and Sargassum are used as food.
Algae increase the level of dissolved oxygen in the immediate environment.
Algin is obtained from red algae, and carrageenan from brown algae.
Solution:
Agar-agar is a gelling agent with unbranched polysaccharide and is used in microbiology as a solidifying agent of liquid culture mediums. It is extracted from the cell wall of red algae, mostly from Gelidium species and Gracilaria species.Laminaria and Sargassum are the brown algae and are cultivated as a crop.Algae are green photosynthetic organisms that release oxygen in immediate vicinity through the process of photosynthesis.The cell wall of brown algae has an inner cellulose layer and outer gelatinous coat which is composed mainly of algin, it is used as an emulsifying agent and a stabilizer.Therefore, the correct answer is option D.