Algae are ubiquitous and a diversified assemblage of aquatic entities which independently can carry out the process of photosynthesis through which they generate oxygen thereby promoting the environmental well-being. Few of the most familiar algae are – the seaweeds (phytoplankton or kelp), the algal bloom found in lakes or pond scum. Algae exist humongously in nature from which we not only reap benefits but they are critical for survival.
Contrary to plants that are capable of photosynthesis, algae are not highly differentiated. This is to say that they do not possess leaves, stem, true roots, a proper vascular system for water and nutrient circulation all through the body structure.
These eukaryotic marine entities range in size from unicellular microalgae till giant kelp. Algae are of great economic importance. Naturally, they are a food source, a fodder, used as a fertilizer, in farming fishes etc. Also, they play a chief role in alkaline reclaiming, can be utilized as an agent that binds the soil, and in various other commercial products.
Characteristics Of Algae
Listed below are the 4 general characteristics of algae
1) Natural Surroundings/Habitat
Majorly, algae are known to be aquatic creatures, typically thriving in saltwater oceans or in freshwater lakes. They have the capability to survive in extremities of temperature, varying carbon dioxide and oxygen concentrations, turbidity and acidity. For example – Dunaliella salina is found in the Dead sea(extremely salty environment), the giant kelp harbours 200meters under the polar ice sheets. The benthic algae thrive on stones, mud. Planktonic are free-floating algae. On land, algae can be found on tree trunks, snow banks, animal fur, desert crusts, hot springs etc.
2) Mode of Nutrition
Most algae are autotrophs as they can carry out the process of photosynthesis through which they nourish themselves with the use of solar energy. To be precise algae are photoautotrophs, that is to say, for nutrient generation, they reflect light energy. The photosynthesis reaction generates oxygen which creates a biological balance in the environment. Some other algae are heterotrophic, wherein different strategies are applied by them to obtain food. For example – Osmotrophy – absorption of a dissolved substance, Auxotrophs – Are required to obtain essential vitamins
3) Reproduction Process
Algae can reproduce their own kind through both the modes of reproduction i.e., sexual and asexual reproduction. Asexual mode of reproduction is carried out through vegetative practices. Through this mode of reproduction, a motile spore is produced. In vegetative processes, simple mitotic division of cells occurs in order to generate replicas and also the fragmentation of a colony. In sexual reproduction, gametes unite from both parents to produce an offspring (gametes are produced by each of the parents through cell division – meiosis).
4) Classification of algae
Algae can be categorized as follows:
- Aquatic algae
- Terrestrial algae
- Algae of notable habitats – These are the algae that occur in odd habitats, namely:
- Halophytic algae – Found in highly concentrated salty environments.
- Symbiotic algae – They grow and mature in association with bryophytes, fungi, angiosperms or gymnosperms. Algal association with fungi is referred to as lichen, example – Nostoc, Rivularia, Cytococcus
- Cryophytic algae – Found on ice or snowy areas
- Thermal algae – These occur in hot water springs, example – Oscillatoria brevis
- Lithophytes – moist rock and stone surfaces
- Epiphytic algae – Grow on different plants
- Endozoic algae – Grow on animal tissues
- Epizoic algae – Grow on animals such as snail and fish
- Parasitic algae – They grow on animals and plants parasitically.
- Psammon – Grow on sandy beaches
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