Q.Write a note on economic importance of algae and gymnosperms.

Algae are of great economic and ecological value:

• Through photosynthesis they carry out at least half of all the carbon dioxide fixed on Earth and raise the dissolved oxygen of their surroundings.
• They are prime primary producers that support aquatic food cycles.
• About seventy marine species, including Porphyra, Laminaria and Sargassum, are eaten as food.
• Brown algae yield algin and red algae yield carrageen — water-holding hydrocolloids.
• Agar, from Gelidium and Gracilaria, is used to grow microbes and to make ice creams and jellies.
• Chlorella, rich in protein, is used as a food supplement. …

Economic importance of algae

Algae matter to people and to life on Earth in several ways:

• Oxygen and carbon fixation — because they photosynthesise, they carry out at least half of all the carbon dioxide fixation on the planet and increase the amount of dissolved oxygen in the water around them.
• Primary producers — they build the energy-rich compounds that feed the food cycles of aquatic animals, acting as the base of these food webs.
• Food — about seventy species of marine algae are used as human food, among them several species of Porphyra, Laminaria and Sargassum.
• Hydrocolloids — certain brown and red algae yield large quantities of water-holding substances used commercially: brown algae give algin, and red algae give carrageen.
• Agar — obtained from Gelidium and Gracilaria, agar is used to grow microbes in the laboratory and in making ice creams and jellies.
• Protein supplement — Chlorella, a single-celled alga very rich in protein, is used as a food supplement and has even been carried by space travellers.

Economic importance of gymnosperms

Gymnosperms are woody plants that span a great range of size — from modest shrubs and medium trees to forest giants, including the redwood Sequoia, one of the tallest tree species on Earth. Two special root associations add to their usefulness: …