Write any three economic importance of algae.

(a) Species of Laminaria and Sargassum are used as food.

(b) Agar, one of the commercial products obtained from Gelidium and Gracilaria is used to grow microbes and in preparation of ice cream and jellies.

(c) Chlorella and Spirullina, the unicellular algae are rich in proteins, hence are use by space travellers as supplement food.