Following are the economic importances of algae and gymnosperms.

Economic importance of algae

Algae have diverse economic uses. They perform half of the total carbon dioxide-fixation on earth by photosynthesis, acting as the primary producers in aquatic habitats.

(a) Food source: Many species of marine algae such as Porphyra, Sargassum, and Laminaria are edible. Chlorella and Spirulinaare rich in proteins. Thus, they are used as food supplements.

(b) Commercial importance: Agar is used in the preparation of jellies and ice-cream. It is obtained from Gelidium andGracilaria. Carrageenin is used as an emulsifier in chocolates, paints, and toothpastes. It is obtained from the red algae.

(c) Medicines: Many red algae such as Corallina are used in treating worm infections.

Economic importance of gymnosperms

(a) Construction purposes: Many conifers such as pine, cedar, etc., are sources of the soft wood used in construction and packing.

(b) Medicinal uses: An anticancer drug Taxol is obtained from Taxus. Many species of Ephedra produce ephedrine, which can be used in the treatment of asthma and bronchitis.

(c) Food source: The seeds of Pinus gerardiana (known as chilgoza) are edible.

(d) Source of resins: Resins are used commercially for manufacturing sealing waxes and water-proof paints. A type of resin known as turpentine is obtained from various species of Pinus.