Group of aquatic organisms belonging to the kingdom of Protista and capable of photosynthesis are referred to as algae. They can be found in a vast array of sizes and shapes. Some instances of algae that we encounter in our daily lives are seaweeds, algal bloom and pond scums.
Algae are a diverse group of organisms which include mainly eukaryotes. Additionally, these organisms can be unicellular or multicellular. These unique features are responsible for some significant economic importance of Algae.
Apart from that discussing the biological and economic importance of algae, we will also discuss the different types of algae.
Features of Algae
Some Interesting Features of Algae Have Been Discussed Below -
Majority of algae discovered till now are aquatic. They can be found in several habitats such as freshwater, saltwater, moist rocks, soil and so on. Nonetheless, some can survive on surfaces outside water such as tree trunks, snowbanks, hot springs etc.
Algae, like plants, are capable of photosynthesis which means they are primary producers in an aquatic environment.
Reproduction in algae can be vegetative, sexual, asexual or a combination of both. Vegetative reproduction includes fragmentation, cell division or fission, whereas asexual reproduction refers to the formation of naked or newly walled spores.
Sexual reproduction in algae is regulated by several environmental factors such as availability of inorganic nutrients, temperature, salinity. When these factors become unfavourable, it induces sexual reproduction.
One of the main differences between algae and plants is that the former does not have connective vascular tissues which facilitate the transportation of water and minerals, like the latter. Hence, algae absorb water via their cells and do not have structures like roots, leaves and stem-like plants
There are several different types of Algae that are found in nature. Some of these can be classified based on their colour. These are –
Rhodophyta (Red algae).
Paeophyta (Brown algae).
Chlorophyta (Green algae).
Pyrrophyta (Fire algae).
Chrysophyta (Golden brown algae).
Xanthophyte (yellow-green algae).
Because of their unique features, algae are of immense importance to human beings and nature alike.
Fish Culture – Some fishes such as Tilapia mossambica feed on certain types of algae. Growing those varieties of algae has successfully facilitated fish culture in India.
Treatment of Sewage Plant – Algae has proved to be very useful in the treatment of sewage plants. It is because they produce oxygen through the process of photosynthesis, which helps in rapid decomposition of sewage.
Used As Food for Human – One of the most crucial economic importance of algae is some species have been used as food for a long time in some parts of the world. Algae are rich in nutrients such as minerals, proteins, essential vitamins A, B, C, E, etc.
For instance, in Japan, a food item called ‘kombu’ is made from laminaria algae. Other varieties such as Porphyra and monostroma are also used to develop food items. A type of seaweed called the Irish moss or carragheen was used as an ingredient to make blancmanges.
Cattle Fodder – Algae species like Laminaria saccharina, Pelvitia, Ascophyllum, etc. are also useful as fodder for cattle in countries like Iceland and Scandinavia.
Natural Soil Fertilisers – It is used as a bio-fertiliser for crops since they can improve the nitrogen content of the soil. Another agricultural importance of algae is that it also enhances soil’s capacity to hold water. Blue-green algae or cyanobacteria are commonly used as fertilisation.
Medicinal Purposes – Apart from food, algae have also been used for medicinal purposes by humans for a long time. Algae variety like sargassum and Laminariales were used to treat conditions like goitre and glandular complications in many eastern countries. The component agar which was used as a laxative to treat stomach disorders is extracted from algae called agarphytes, gelidium, pterocladia etc. furthermore, research is being carried out regarding other medicinal properties of ingredients in algae.
As we saw in the previous section, there are several economic importance of algae. However, not all algae are useful, some species can be quite toxic to the environment. Growth of algal blooms in large quantities can disrupt the balance of aquatic habitat and result in toxin production. Drinking water from an alga infested water body can lead to casualties, especially for animals and cattle. Apart from drinking, it cannot be used for recreational or agricultural purposes.
While preparing for NEET, you should focus on understanding the underlying concepts of each topic, such as economic importance of Algae instead of memorising terms and definitions.
Refer to specialised study guides for NEET, which will enable you to gain more clarity on a topic. It will allow you to retain more information on the day of examination. Furthermore, divide your time equally between physics, chemistry, and biology.
Apart from revision of concepts like economic importance of algae botany, sit for as many mock tests as is possible. It will help you improve your speed as well as accuracy.
1. Why are Algae Not Considered to Be a Part of Kingdom Plantae?
Ans. Algae do not have stems, roots and leaves like plants. As a result, they don’t possess vascular tissues that facilitate the transport of water and nutrients from roots to leaves. However, these unique features are responsible for many economic importance of Algae.
2. What are the Various Modes of Asexual Reproduction Seen in Algae?
Ans. The different modes of asexual reproduction seen in algae are zoospores, aplanospores, tetraspores, akinetes, exospores, endospores.
3. What are Some of the Features of Chlorophyta or Green Algae?
Ans. These types of algae are mostly found in a freshwater environment. They contain chloroplasts and can carry out photosynthesis. The cell walls of green algae are composed of cellulose. Examples of sea algae are sea lettuce, dead man’s fingers, horsehair algae.