HARITHA,Subject Matter Expert at Edumarz
Solution:
ALGAE
Algae are chlorophyll containing, simple, thalloid, autotrophic and mainly aquatic organisms.They are found in different types of habitats such as moist stones, soils and wood.They also form symbiotic relationships with other organisms such as fungi(lichen) and animals(sloth bear).The mode of reproduction of algae is by vegetative propagation,sexual and asexual methods.
Economic importance of algae
Half of the total fixation of carbon dioxide on earth is done by algae using photosynthesis
They also increase the level of oxygen in their surrounding environment
They are primary producers of rich energy compounds that form basis of food cycle of aquatic organisms
Marine algae such as Porphyra,Laminaria and Sargassum used as food
Some marine algae like brown and red algae produce large amounts of hydrocolloides
-Hydrocolloids are water holding substances
Agar,prepared from Gelidium and Gracilaria are used to culture microbes and also for preparing ice creams and jellies
The algae,Chlorella is used as food supplement by space travellers
GYMNOSPERMS
Gymnosperms are plants that have naked seeds.It includes plants that are medium-sized, tall and shrubs.The tallest tree species, the giant redwood tree sequoia, is included in gymnosperms.In some species,roots form fungal associations in the form of mycorrhiza (Pinus).In some other species,like cycas,small specialised roots called coralloid roots are present and they form associations with nitrogen-fixing cyanobacteria.
Economic importance of gymnosperms
Used for making medicines
Wood is used for making furniture and paper
Used in production of gums