How Algae Impact Life and the Environment
We all have seen green coloured, carpet-like layers, growing over plants, near taps, water tanks, ponds, rocks, and other moist places. They are the living, eukaryotic, and photosynthetic organisms, which are called Algae.
Algae are aquatic organisms that have the potential to conduct photosynthesis. Algal blooms, phytoplankton, and pond scum are some of the different types of algae found in nature.
What is Algae?
Algae are a diverse group of eukaryotic, photosynthetic life forms of kingdom Protista. These organisms exist in environments ranging from oceans, rivers, and lakes to ponds, brackish waters, and even snow. Usually, algae are green in colour, but they can also be found in a variety of different colours. Algae can be either unicellular or multicellular organisms, which lack a well-defined body structure, hence they are grouped into Thallophytes.
Some can form a symbiotic relationship with other organisms but algae are free-living organisms. The mode of reproduction in algae occurs in both asexual and sexual forms. There are three types of algae, which are mainly classified based on the presence of their pigments:
Red Algae
Green Algae
Blue-green Algae
Interesting Facts About Algae
Algae are a vast group of aquatic organisms, which are capable of conducting photosynthesis on their own. They are neither plant, animal or fungi and vary in their size, which plays economical and beneficial roles in environments. There are a lot of interesting facts about algae, which are not known to everyone.
Let us have a look at a few of them.
Fact-No-1
In marine or freshwater environments algae are generally found. They play an important role in the ecosystem. Some species are used in the production of biofuels and some are also used as fertilizers and livestock feed.
Fact-No-2
A few species of algae are used in pharmaceutical industries for the production of medicines. There are many diseases which have been cured by algae. The Red algae are mainly used in treating asthma, cold sores, stomach disorders, urinary infections, and also helps in boosting the human immune system.
Fact-No-3
Algae are highly rich in vitamins and minerals and are an important source of food in different parts of Asia.
Fact-No-4
Like all green plants of Kingdom Plantae, Algae also contain chlorophyll pigments in their cells and manufacture their own food through the process of photosynthesis.
Fact-No-5
Dino-flagellate, certain species of algae produce bioluminescence that can be easily visible during night time. This emitted light is sufficient enough for a person to read the newspapers without any additional light source.
Fact-No-6
Microscopic algae or macrophytes are the species of algae, which are typically found growing on the freshwater and marine systems. They are usually found floating on the water, which multiplies rapidly, turning the water green or red and serves as the ultimate source of food for almost all marine life.
Fact-No-7
Algae are a major part of the aquatic ecosystem. They serve as food for many aquatic organisms and contribute to the aquatic food chain.
Fact-No-8
There are thousands of different kinds of algae found in different colours and forms. These eukaryotic and photosynthetic organisms are found everywhere on the planet, even in saltwater, in very low-temperature regions, on snow lands and ice crystals.
Fact-No-9
Different species of Algae are used in the human diet. Seaweeds also referred to as macroalgae are highly nutritious, rich in vitamins and minerals and represent an important source of food in certain countries.
Fact-No-10
Algae are also used in many wastewater treatment plants, which reduce the carbon dioxide and other emissions in water by increasing the oxygen levels in the water bodies. Algae are also used in power plants by reducing carbon dioxide emissions and are being used as a replacement for harsh chemicals in the wastewater treatment.
Fact-No-11
Algae are used in many sewage water treatment plants and help in reducing the need for harmful chemicals and are used in some power plants to reduce carbon dioxide emissions.
Fact-No-12
Along with the beneficial Algae species, there are some algae, which may cause harm to other living species. In some water bodies, these algae grow and reproduce a lot and cause algal blooms, which affects both fishes and other aquatic animals.
FAQs on Essential Facts About Algae
1. What are algae?
Algae are a diverse group of simple, typically aquatic, photosynthetic organisms. They are largely classified under Kingdom Protista. Unlike plants, they have a simple body structure called a thallus, which is not differentiated into true roots, stems, or leaves. They can be unicellular, like Chlamydomonas, or multicellular, like kelp.
2. What are the key features that define algae?
The most important features of algae include:
Photosynthetic Nutrition: They contain chlorophyll and other pigments to make their own food.
Aquatic Habitat: Most algae are found in marine or freshwater environments, though some live on moist soil, rocks, or even snow.
Thalloid Body: Their body is a simple thallus, lacking the complex vascular tissues (xylem and phloem) found in higher plants.
Reproduction: They reproduce through vegetative, asexual (spore formation), and sexual methods.
3. How are algae classified according to the NCERT syllabus?
Algae are primarily classified into three main classes based on their major photosynthetic pigments:
Chlorophyceae (Green Algae): Contain chlorophyll a and b, giving them a grass-green colour. Their cell walls are made of cellulose, and they store food as starch. Examples include Spirogyra and Volvox.
Phaeophyceae (Brown Algae): Contain chlorophyll a, c, and a pigment called fucoxanthin, which gives them their olive-green to brown colour. They are mostly marine. Examples include Laminaria and Fucus.
Rhodophyceae (Red Algae): Contain chlorophyll a, d, and a pigment called phycoerythrin, which gives them their red colour. This pigment allows them to absorb blue light and live in deep waters. Examples include Gelidium and Porphyra.
4. Why are algae considered thallophytes and not true plants?
Algae are called thallophytes because their body structure is a simple thallus, which is undifferentiated. This means they lack the specialised organs found in true plants, such as roots for anchorage and absorption, stems for support, and leaves for photosynthesis. Furthermore, they do not have the complex vascular system (xylem and phloem) that transports water and nutrients in higher plants.
5. What is the economic importance of algae?
Algae have significant economic importance. They are responsible for about half of the total carbon dioxide fixation on Earth through photosynthesis. Certain species are used to produce valuable commercial products like Agar (from Gelidium and Gracilaria) used in labs and food, and Algin (from brown algae) used as a thickener. Some algae, like Chlorella and Spirulina, are rich in protein and used as food supplements.
6. What is the main difference between algae and fungi?
The fundamental difference lies in their mode of nutrition. Algae are autotrophic; they contain chlorophyll and perform photosynthesis to create their own food. In contrast, fungi are heterotrophic; they lack chlorophyll and obtain nutrients by absorbing organic matter from their surroundings, either as decomposers (saprophytes) or by living on other organisms (parasites).
7. How do the reproductive methods in algae vary?
Algae exhibit three types of reproduction:
Vegetative Reproduction: Occurs mainly through fragmentation, where the algal thallus breaks into pieces, and each piece grows into a new individual.
Asexual Reproduction: Involves the production of different types of spores, the most common being zoospores. These are flagellated, motile spores that germinate to form new plants.
Sexual Reproduction: Involves the fusion of two gametes. It can be isogamous (fusion of similar-sized gametes), anisogamous (fusion of dissimilar-sized gametes), or oogamous (fusion of a large, non-motile female gamete with a small, motile male gamete).
8. Why are blue-green algae (Cyanobacteria) often studied alongside algae if they are bacteria?
Blue-green algae, or Cyanobacteria, are prokaryotic organisms, meaning they lack a true nucleus and membrane-bound organelles, which makes them bacteria (Kingdom Monera). However, they are often studied in phycology (the study of algae) for a key functional reason: like true algae, they perform oxygenic photosynthesis. Due to this shared ecological role as primary producers in aquatic environments, they were historically misclassified and are still discussed together with algae for comparative and ecological purposes.
