a) Some species of algae are used as cattle feed.
b) Algin, a substance obtained from brown algae is used in preparation of ice creams and
chocolates.
c) Agar, a substance obtained from Gelidium a red algae is used as a medium for
culturing bacteria in the laboratory.
d) Red algae called Porphyra is used as a condiment.
e) Algae growing in decaying water liberate oxygen and help in purification of water.
f) Laminaria, a brown algae is used in the production of potassium and iodine.