Algae - Types & Examples, Defination
Algae are autotrophic, simple structured organisms found in freshwater lakes, oceans, and different water-based habitats. Aquatic ecosystems can not survive without algae, as they provide nutrients to several aquatic animals. Some algae are of large size such as seaweeds, whereas others may exist in the form of single-celled organisms. These are studied as an essential part of biology, especially for students preparing for the NEET and other competitive tests. This article includes algae definition, types of algae diagram and possible uses of algae for algal biofuel.
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What is Algae?
Algae represent a simple, autotrophic organism capable of generating energy from the light provided by sunlight through a process called photosynthesis. It may be unicellular or multicellular; it can pertain to any taxonomic group. Besides their existence in different kinds of environments, algae also play an essential role in providing oxygen to our planet.
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Characteristics of Algae
Some major characteristics of algae are:
- Algae are Chlorophyllous and photosynthetic in nature.
- They are found in a wide variety of habitats. Some may be exclusively freshwater, while others can be perfectly saltwater species.
- Algae reproduce both sexually and asexually; although the latter method is their main mode of reproduction.
- Algae are unicellular and possess a simple structure; at times, even its thallus is filamentous or sheet-like, while at times it is branched.
- Algae exhibit different colours because of the occurrence of the various pigments present which are green, brown, or red algae.
Classification of Algae
The classification of algae is outlined as follows:
Chlorophyta (Green Algae)
- Range from basic organisms such as Chlamydomonas to complex forms.
- Contains chloroplasts, which store energy, and include chlorophylls A and B.
- Cellulose is commonly used to make cell walls.
- Found in moist terrestrial habitats (such as soils and rocks) and freshwater.
Example
- Volvox
- Chlamydomonas
- Spirogyra
- Ulva (sea lettuce)
Phaeophyta (Brown Algae)
- Fucoxanthin is a pigment that gives large, multicellular brown algae seaweeds their brown or olive colour.
- Prevalent in cool coastal environments, particularly on coastal rocks and kelp beds with a high concentration of nutrients.
Examples
- Sargassum
- Fucus (Rockweed)
- Laminaria (Kelp)
Rhodophyta (Red Algae)
- Rhodophyta comprises multicellular algae predominantly found in marine habitats, characterized by their red to purplish colour due to phycoerythrin pigment.
- Red algae thrive in various marine environments, forming large beds or reefs.
Examples
- Gelidium
- Porphyra (Nori)
- Corallina
Blue Green Algae (Cyanobacteria)
- Blue green algae, also known as cyanobacteria, are a group of photosynthetic algae that can exist as single cells or form multicellular colonies.
- They are characterized by their blue green colouration, which is primarily due to the presence of chlorophyll-a and the pigment phycocyanin.
- Blue green algae are versatile and can be found in a variety of aquatic environments, including freshwater lakes, ponds, rivers, and marine ecosystems.
Examples
- Anabaena
- Microcystis
- Nostoc
Other Types of Algae
Some other types of algae are:
Diatoms
- Diatoms are unicellular algae encased in silica walls (frustule), exhibiting diverse shapes like cylindrical and star-like forms. They are essential for converting carbon dioxide into oxygen.
- Found in both freshwater and marine environments, diatoms dominate nutrient-rich areas and form a crucial part of the aquatic food chain.
Examples
- Navicula
- Diatomaceous Earth
Dinoflagellates
- Dinoflagellates are unicellular algae possessing two flagella, allowing them to swim. They can be autotrophic, photosynthetic, or heterotrophic.
- These algae are prevalent in both marine and freshwater environments and can cause harmful algal blooms.
Examples:
- Symbiodinium
- Gonyaulax
- Karenia brevis
Examples of Algae
Some notable examples of algae include:
- Chlorella: A unicellular green alga known for its high nutritional value.
- Spirulina: A cyanobacterium that is often consumed as a health supplement.
- Nori: A red alga used in sushi.
Algal Biofuel
The use of algae to produce biofuel is the focus of the new field of algal biofuel. Lipids produced by the cultivation of algae can be transformed into biofuel. This strategy is a significant topic in research on renewable energy since it offers a sustainable substitute for fossil fuels. Algal biofuel has immense potential because, in comparison to conventional crops, algae can develop quickly and effectively, yielding large amounts of biofuel per acre.
Tips, Tricks and Strategies to Study Algae for Exams
Here are some tricks to study Algae for different exams:
Types of Algae: "GRaB Dark Colours"
- Green Algae (Chlorophyta)
- Red Algae (Rhodophyta)
- Brown Algae (Phaeophyta)
- Diatoms (Bacillariophyta)
- Cyanobacteria (Blue-Green Algae)
Characteristics of Algae: "SCOPES"
- Structure: Simple
- Cellular Organization: Unicellular or multicellular
- Oxygen Producers: Major source of oxygen in aquatic environments
- Pigments: Chlorophylls and accessory pigments like carotenoids
- Environment: Aquatic (freshwater and marine) or terrestrial
- Size: Varies from microscopic to giant seaweeds
Reproductive Methods in Algae: "FABBS"
- Fission (Binary)
- Asexual Reproduction
- Budding
- Binary fission
- Spores
Types of Questions and Weightage of Algae in Exams
The table below indicates the weightage and types of questions asked on Algae:
| Exam Type | Types of Questions | Weightage |
|---|---|---|
| CBSE Board Exams | Short answers on algae classification, structures, and diagrams | 3-4% |
| NEET | MCQs on types of algae, their life cycles, and ecological roles | 2-3% |
| AIIMS | Assertion and reason questions on the importance of algae in ecosystems | 2-3% |
| Nursing Entrance Exams | Scenario-based questions on the use of algae in food and medicine | 1-3% |
| Paramedical Exams | True/False questions on characteristics of algae and their significance | 1-3% |
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| Parts of Plants | Modification of Root |
| Floral Formula | Modification of Stem |
| Gymnosperms | Angiosperms and Gymnosperms Difference |
Recommended Video of Algae
Frequently Asked Questions (FAQs)
There are various categories of algae some of which include green algae (Chlorophyta), red algae (Rhodophyta), brown algae (Phaeophyta), diatoms (Bacillariophyta), dinoflagellates (Dinophyta).
Algae are relevant in the ecosystem as primary producers, oxygen suppliers, sources of food for other species, articles that support species’ diversity, and finally nutrients cycling in aquatic and on land.
Sexual and asexual means of reproducing are found in algae. In sexual reproduction, there is the coming together of gametes while in asexual reproduction there is cell division, fragmentation and spore or other vegetative body formation.
Such economic uses include; food supplements like nori and spirulina, biotreatment of wastewater, pharmaceutical products like agar and carrageenan; and sources of valuable compounds such as omega-three fatty acids and antioxidants.
Algal blooms are also brought by pollution by nutrients, particularly nitrogen and phosphorus, warm water, low wind, and sunlight. Some of the control strategies include; micronutrient-eligible agriculture management and effluent treatment, buffer zones, and physical and biological means of preventing blooms.
Algae are photosynthetic, simple-structured organisms that live mainly in aquatic environments, including freshwater, saltwater, and moist terrestrial areas. It may be unicellular or multicellular and is classified under the kingdom Protista. The algae are not true plants since they do not have roots, stems, and leaves.
Algae are essentially phototrophic organisms that convert sunlight into energy with the help of chlorophyll. They can be either microscopic-sized phytoplankton or large seaweeds. Major characteristics of algae include:
- Photosynthesis: These are chlorophyll-containing organisms and thus capable of doing photosynthesis to produce oxygen and organic matter.
- Habitat: Most algae are aquatic, though some of them are freshwater, and a few of them can exist in moist soils or surfaces.
- Structure: Algae are unicellular like diatoms or multicellular like kelp and lack the characteristic tissues found on higher plants.
- Reproduction: These reproduce asexually, either by fragmentation, spores, or through binary fission; some of them also reproduce sexually.
- Tyes: Algae can vary in colour from blue-green, brown, and red depending on the type of pigments contained.
- Production of Oxygen: The majority of the world's oxygen is produced through photosynthesis by algae.
- Source of Food: They are important to the aquatic food web because, in most marine organisms, they happen to be the basic food element, such as fish and zooplankton.
- Habitat: Many freshwater organisms live in algae and consequently add to the biodiversity of their ecosystem.
- Nutrient cycling: Their roles are important in the aquatic environment; they help recycle carbon, nitrogen, and phosphorus.
- Biotechnology Applications: Algae find their uses in the production of biofuels, pharmaceuticals, and bioremediation.
- Food: Some of these algae - like spirulina and nori - can be eaten raw, while others are used as dietary supplements.
- Animal Feed: Algae is a nutrient supplement to the diet in aquaculture and it is also provided as animals' livestock feed.
- Fertilizers: Organic fertilizer prepared from algal biomass can help raise the fertility of the soil.
- Biofuels: Biodiesel and bioethanol could be produced by processing algae. End.
- Pharmaceutical: Algae are used as sources for a variety of bioactive compounds to produce medicines like antioxidants and anti-inflammatory drugs.
- Cosmetics: Algal extracts have found application in most cosmetics and skin care products due to their moisturizing and soothing nature to the skin.
- Water Treatment: Algae are applied in bioremediation; that is, they adsorb pollutants and purify water.
- Industrial Products: Algae could be applied to produce biodegradable plastics and other sustainable products.
- Biotechnology: Algae are used in research and biotechnology for genetic engineering and as model organisms.
- Nutritional Supplements: Algal supplements, including spirulina and chlorella, are sold as nutritional or health-promoting agents with vitamins, minerals, and protein content.
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Questions related to
Correct Answer: CADB
Solution : The correct choice is the third option.
The logical flow of information is:
- The paragraph illustrates the concept of omnivores and their dietary adaptability. It begins (C) by defining omnivores as animals capable of thriving on both plant and animal substances.
- Following this, (A) details how omnivores obtain energy and nutrients by digesting various components from both plant and animal sources. This showcases their ability to derive sustenance from a wide range of food types.
- Then, (D) elaborates on the adaptability of omnivores by highlighting their capacity to include diverse food sources like algae, fungus, and bacteria in their diet, underscoring their flexibility in consumption.
- Finally, (B) concludes the paragraph by indicating that the diverse range of animals classified as omnivores can further be divided into sub-categories based on their specific dietary habits, emphasising the wide spectrum of dietary behaviours within the omnivore classification.
Therefore, the correct order is CADB.
Correct Answer: Hematology : Blood
Solution : Given:
Phycology : Algae (Here, Phycology is the scientific study of algae.)
First option: Eccrinology : Amphibians; Eccrinology is the branch of medical science concerned with secretions of the eccrine glands.
Second option: Selenography : Secretions; Selenography is the study of the moon's surface.
Third option: Hematology : Blood; Hematology is the study of blood and blood disorders.
Fourth option: Entomology : Soil; Entomology is the scientific study of insects.
So, only the third option follows the same pattern as followed by the given pair of words. Hence, the third option is correct.