Q.5:- Write a note on economic importance of algae and gymnosperms.
Economic importance of algae: Algae are useful to man in a variety of ways. They perform half of the total carbon dioxide-fixation on earth by photosynthesis, acting as the primary producers in aquatic habitats. Many species of marine algae such as Porphyra, Sargassum, and Laminaria are edible. Chlorella and Spirulina are rich in proteins. Thus, they are used as food supplements. Agar is used in the preparation of jellies and ice-cream. It is obtained from Gelidium and Gracilaria. Carrageenin is used as an emulsifier in chocolates, paints, and toothpastes. It is obtained from the red algae. Many red algae such as Corallina are used in treating worm infections.
Economic importance of gymnosperms: Gymnospermous plants are widely used as ornamentals. Many conifers such as pine, cedar, etc., are sources of the soft wood used in construction and packing. Medicinal uses: An anticancer drug Taxol is obtained from Taxus. Many species of Ephedraproduce ephedrine, which can be used in the treatment of asthma and bronchitis. The seeds of Pinus gerardiana are edible. 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.