BlogNCERTImportant Topic Of Biology: Algae 

Important Topic Of Biology: Algae 


Algae are defined as a group of generally submarine, photosynthetic, and nexus-bearing organisms that warrant the true roots, stems, leaves, and specialized multicellular reproductive structures of shops. Their photosynthetic colors are also more varied than those of shops, and their cells have features not planted among shops and creatures. Algae are eukaryotic organisms and contain three types of double-membrane-bound organelles the nexus, the chloroplast, and the mitochondrion. Although some are multinucleate, there’s only a single nexus in utmost algal cells. The algae can be divided into several types grounded on their vegetative or growing state morphology. Filamentous forms have cells arranged in chains like strings of globules. Some fibers (e.g., Spirogyra) are unbranched, whereas others (e.g., Stigeoclonium) are fanned and bush-like. In numerous red algae (e.g., Palmaria), multitudinous conterminous fibers indirectly produce the alga’s gross morphological form. Parenchymatous (tissuelike) forms, similar to the giant kelp (Macrocystis), can measure numerous meters in length. Coenocytic kinds of algae, identical to the green seaweed Codium, grow to reasonably large sizes without forming different cells. Coenocytic algae are unicellular, multifaceted algae in which cell sides don’t subdivide into the protoplasm (cytoplasmic and nuclear content of a cell). Some algae have flagella and can swim through water. These flagellates range from single cells, similar to Ochromonas, to social organisms with thousands of cells, identical to Volvox. Coccoid microorganisms, equal to Scenedesmus, typically have an exact number of cells per colony, produced by a series of rapid-fire cell divisions when the organism is first formed; once the precise cell number is attained, the organism grows in size but not in cell number.


Algae represent a vastly different institute of ancient shops comprising different evolutionary lineages of substantially photoautotrophic organisms. The other groups of algae are of polyphyletic origin and epitomize the maturity of being divisions of shops. Algae are thallophyta; their vegetative body isn’t organized in roots and leafy stems like the cormophyte. Numerous algae live in solitary cells, colonies, fibers, or primitive foliage bodies and don’t have a vascular system. In discrepancy to the phanerogams ( shops producing seeds), the algae are cryptogams that propagate by‘ concealed or retired reproductive strategies. Following a generality of a branch of living organisms into five fiefdoms (Monera, Protoctista, Fungi, Animalia, and Plantae), the prokaryotic algae ( blue-green algae, Cyanobacteria, Cyanoprokaryota) are spotted in the Monera (Eubacteria) and the eukaryotic algae in the Protoctista. Hence, the algae don’t belong to the area of Plantae. Nonetheless, it’s widely accepted (because of photosynthesis as the collective characteristic) to interpret algae as‘ lower shops’ in distinction to the vascular‘ advanced shops.’

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    The eukaryotic algae retain membrane-bound organelles similar to capitals, mitochondria, and plastids. The prokaryotic Cyanobacteria don’t parade similar organelles; their DNA and photosynthetic thylakoids lie free in the cytoplasm. The combination of eukaryotic algal groups and prokaryotic Cyanobacteria demonstrates this natural term’s miscellaneous and artificial character. On the other side, the addition of Cyanobacteria in the group of algae is justified by several ecophysiological and evolutionary honest arguments. Like the eukaryotic algae, Cyanobacteria are suitable for photosynthetic oxygen products. The proposition of endosymbiosis has given substantiation for the elaboration of chloroplasts by the objectification of Cyanobacteria into eukaryotic host cells. Endosymbiosis is discovered as a significant force in developing different algal lineages. Algae parade a fascinating diversity of life forms and strategies in response to the terrain.



    The term”algae” covers numerous different organisms able to produce oxygen through photosynthesis (the process of harvesting light energy from the sun to induce carbohydrates). These organisms aren’t inescapably nearly affiliated. Still, certain features unite them while distinguishing them from the other major group of photosynthetic organisms in the land shops. Under these characteristics, the general term”algae” includes prokaryotic organisms — cyanobacteria, also known as blue-green algae — and eukaryotic organisms (all other algal species). The maturity of algae lives in submarine territories. Yet, the word” submarine” is nearly limited in its ability to encompass these territories’ diversity. Algae can reproduce through asexual or vegetative styles and via sexual reduplication.

    Classification of Algae


    Cyanobacteria These algae have” primary” chloroplasts, i.e. the chloroplasts are encircled by two membranes and presumably developed through a single endosymbiotic event. The chloroplasts of red algae have chlorophylls a and c ( frequently) and phycobilins, while green algae have chloroplasts with chlorophyll a and b without phycobilins. Land shops are also painted to green algae and presumably developed from them; therefore, the Chlorophyta is a family taxon to the shops; occasionally, the Chlorophyta, the Charophyta, and land shops are grouped as the Viridiplantae.

    Green algae

    These groups have green chloroplasts containing chlorophylls a and b. Their chloroplasts are girdled by four and three membranes independently and were presumably retained from ingested green algae. Chlorarachniophytes, which belong to Cercozoa, contain a small nucleomorph, a relict of the algae’s nexus. Euglenids, which belong to Euglenozoa, live primarily in fresh water and have chloroplasts with only three membranes. The endosymbiotic green algae may have existed acquired through myzocytosis rather than phagocytosis.

    Red algae

    These groups have chloroplasts containing chlorophylls a and c and phycobilins. The shape varies from factory to plant; they may be discoid, plate-like, reticulate, mug-shaped, spiral, or strip-shaped. They’ve one or further pyrenoids to save protein and bounce. The ultimate chlorophyll type isn’t known from any prokaryotes or primary chloroplasts, but inheritable parallels with red algae suggest a relationship.

    In the first three of these groups (Chromista), the chloroplast has four membranes, retaining a nucleomorph in cryptomonads, and they probably partake in a common pigmented ancestor. However, other substantiation casts mistrust fullness on whether the heterokonts, Haptophyta, and cryptomonads are more nearly affiliated than other groups.

    The typical dinoflagellate chloroplast has three membranes, but considerable diversity exists in chloroplasts within the group, and several endosymbiotic events supposedly passed. The Apicomplexa, a group of nearly affiliated spongers, also have plastids called apicoplasts, which aren’t photosynthetic but appear to have a common origin with dinoflagellate chloroplasts.

    Importance of chapter for JEE Main, Neet, and Board exams

    The study of algae is essential as a donation of algae to our terrain and well-being is the generation of oxygen through photosynthesis. Algae are necessary because they produce about half the oxygen in Earth’s atmosphere. Algal biofuels are a promising relief for fossil energies. All algae can produce energy-rich canvases, and several microalgal species naturally accumulate high situations of canvas in their dry mass. Also, algae are planted in different territories and can reproduce snappily. They also use carbon dioxide. Algae help to keep atmospheric carbon dioxide situations stable by storing (the gas) in organic accouterments that include canvas deposits and inorganic carbonate jewels.

    Also read: Anatomy and Function of Different Parts of Flowering Plants


    Are algae a plant or bacteria?

    Algae are sometimes considered plants and sometimes protists.

    Which algae are most harmful?

    Blue-green algae are the most harmful algae.

    What exactly are algae?

    Algae is a group of aquatic organisms that can perform photosynthesis.

    Who is known as the father of Algae?

    M.O.P Iyengar

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