Monday, January 23, 2023

What Is Autotroph In Biology

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Carnivorous And Parasitic Plants

Autotrophs and Heterotrophs

Among plants, carnivorous plants, such as venus flytrap, tropical pitcher plants, and sundews, can derive some nutrients from trapping and consuming insects. At the same time, they still keep the ability to generate energy from photosynthesis. Some semi-parasitic plants, like mistletoe and dodder, are also mixotrophs.

Examples of carnivorous plants.

Kelp Forests And Sea Urchins

Kelp is an autotroph and a very advanced form of algae. These underwater plants can tower several meters off the seafloor. Gathering the energy of sunlight into edible materials, a kelp forest can be an incredibly productive ecosystem. The kelp not only provide food but shelter and even nesting grounds for many species.

The above picture shows a diver swimming in a kelp forest. The kelp in this picture is healthy and flourishing. This healthy ecosystem, based on the autotroph, can sustain a variety of life. However, human influences and natural diseases can easily wipe out these productive environments in a very short amount of time. For this to happen, a well-documented series of cascading events must take place.

Above is a sea urchin, one of the only real threats to the kelp. Sea urchins crawl along the sea floor eating algae which grows on the rocks and coral. To them, kelp is a delicious and nutritious prize and they can eat large amounts of it. While other fish eat the leaves of the kelp, these can be regrown and the autotroph will survive and continue to produce. Sea urchins destroy the one thing the autotroph needs to survive, the holdfast.

Can Animals Live Like Plants

Mixotrophy is less common among animals. There are some examples living in coral reefs. Several members of cnidarians host endosymbiotic microalgae within their cells, thus making them mixotrophs.

These sea anemones have beautiful green color due to symbiotic algae living inside. This symbiotic relationship between algae and sea anemones is beneficial to both. The sea anemones get oxygen and nutrients, whereas the algae get protection.

Elysia chlorotica is one of the solar-powered sea slugs, utilizing solar energy like plants to generate energy. The sea slug eats and steals chloroplasts from the alga Vaucheria litorea. The sea slugs then incorporate the chloroplasts into their own digestive cells, where the chloroplasts continue to photosynthesize for up to nine months thats even longer than they would perform in algae. The sea slugs stay nourished thanks to the sugars produced by photosynthesis.

Elysia chlorotica, a sea slug steals photosynthetic chloroplasts from algae.

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Primary Production In Tropical Streams And Rivers

Aquatic algae are a significant contributor to food webs in tropical rivers and streams. This is displayed by net primary production, a fundamental ecological process that reflects the amount of carbon that is synthesized within an ecosystem. This carbon ultimately becomes available to consumers. Net primary production displays that the rates of in-stream primary production in tropical regions are at least an order of magnitude greater than in similar temperate systems.

Autotrophs And Heterotrophs What Are The Difference

Heterotroph And Autotroph Vector Illustration Labeled Biological ...

Autotrophs and heterotrophs are two nutritional groups found in ecosystems. The main difference between autotrophs and heterotrophs is that autotrophs can produce their own food whereas heterotrophs eat other organisms as food.

Self-feeders produce their own food Other eaters do not produce their own food
Make food from inorganic materials Get food by eating other organisms
At the primary level in a food chain At the secondary and tertiary levels in a food chain
Are either photoautotrophs or chemoautotrophs Are either herbivores, carnivores, omnivores, or detritivores
Plants, algae, some bacteria, and archaea Animals, fungi, some bacteria, protists, and parasitic plants

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Iron Bacteria Acidithiobacillus Ferrooxidans

The bacterium Acidithiobacillus ferrooxidans obtains energy from ferrous iron. In the process, it converts the iron atoms from a molecular form where they cannot be dissolved in water to a molecular form where they can.

As a result, Acidithiobacillus ferrooxidans has been used to extract iron from ores that could not be extracted through conventional means.

The field of biohydrometallurgy is the study of using living organisms to obtain metals by dissolving them in water, where they can be further processed.

What Is An Autotroph And Give 2 Examples

Examples of AutotrophsAlgae are also photoautotrophs. Algae are small organisms that are usually found in aquatic environments. While algae also have chloroplasts and may sometimes look like plants, they are very different. Plants are stationary – they set up roots and do not move once they start to grow.

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What Is Autotroph In Your Own Words

An autotroph is a plant that can make its own food. Autotroph is a biological term that breaks down to mean “self-” “nourishing” . Autotrophic organisms synthesize their own food from simple organic substances. If you were an autotroph, you wouldn’t need to eat and you’d still have plenty of energy.

Iiicammonia Assimilation And Plant Nitrogen Uptake

Autotrophs & heterotrophs (nutrition modes) | Life processes | Biology | Khan Academy

Autotroph organisms assimilate inorganic nitrate ions into their body substances after conversion of NO3 into ammonium. The combined process of nitrate reduction and ammonia assimilation is referred to as the assimilatory nitrate reduction. Immoblization of nitrogen into organic N reduces the probability of nitrogen loss from the ecosystem.

Until recently, it was thought that all N taken up by plants was taken up as a mineral form through their roots or as a gas through leaves and stomata . There is an accumulating body of evidence to suggest that plant roots are capable of taking up relatively simply amino acids directly, thus bypassing N mineralization . This pathway is particularly important for boreal and tundra plants. Plant associations with mycorrhizal fungi may also play an inportant role in the nitrogen nutrition of plants through increasing surface area available for absorption and the production of proteases.

Peter Convey, in, 2013

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Chemoautotrophic Bacteria Types And Examples

Have you ever wondered how some bacteria survive in such extreme environments? Chemosynthetic autotrophs do so by relying on chemical compounds to get energy.

Chemoautotrophic bacteria perform chemosynthesis, which utilizes chemical energy. They lack photosynthetic pigments. Here carbon sources can be carbon dioxide, hydrogen sulphide, methane, etc. The chemical energy is produced from oxidation of inorganic compounds such as hydrogen, H2S, carbon monoxide, ammonia, methane, iron salts, nitrite, etc. The energy liberated from oxidation is trapped in ATP for the synthesis of organic compounds.

They can be aerobic or anaerobic. Depending on the source, where they derive energy from, they are categorised into various types such as sulphur bacteria, hydrogen bacteria, iron bacteria, nitrogen bacteria, methanotrophs, etc. They play an important role in nutrient recycling such as nitrogen, phosphorus, sulphur, iron, etc.

Sulphur bacteria

They oxidise, hydrogen sulphide or thiosulphates to molecular sulphur or sulphates. E.g. Beggiatoa, Thiobacillus, Thiothrix, Sulfolobus, etc.

2H2S + O2 2H2O + 2S + Energy

Nitrogen bacteria

Nitrifying bacteria convert ammonia to nitrite and then to nitrate. In this oxidation process, energy is released. Nitrate is utilized by plants. E.g. Nitrosomonas, Nitrobacter

NH3 + O2 NO2 + H2O + Energy

2NO2 + O2 NO3 + Energy

Hydrogen bacteria

2H2 + O2 2H2O + Energy


Iron bacteria

4FeCO3 + O2 + 6H2O 4Fe3 + 4CO2 + Energy

What Is An Autotroph Definition And Examples

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  • B.A., Biology, Emory University
  • A.S., Nursing, Chattahoochee Technical College

An autotroph is an organism that can produce its own food using inorganic substances. In contrast, heterotrophs are organisms that cannot produce their own nutrients and require consumption of other organisms to live. Autotrophs are important parts of the ecosystem known as producers, and they are often the food source for heterotrophs.

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Solar Dependence And Food Production

Some organisms can carry out photosynthesis, whereas others cannot. An autotroph is an organism that can produce its own food. The Greek roots of the word autotroph mean self feeder . Plants are the best-known autotrophs, but others exist, including certain types of bacteria and algae . Oceanic algae contribute enormous quantities of food and oxygen to global food chains. Plants are also photoautotrophs, a type of autotroph that uses sunlight and carbon from carbon dioxide to synthesize chemical energy in the form of carbohydrates. All organisms carrying out photosynthesis require sunlight.

Figure 1. Plants, algae, and certain bacteria, called cyanobacteria, are photoautotrophs that can carry out photosynthesis. Algae can grow over enormous areas in water, at times completely covering the surface.

Figure 2. The energy stored in carbohydrate molecules from photosynthesis passes through the food chain. The predator that eats these deer is getting energy that originated in the photosynthetic vegetation that the deer consumed.

Figure 3. Photosynthesis uses solar energy, carbon dioxide, and water to produce energy-storing carbohydrates. Oxygen is generated as a waste product of photosynthesis.

The following is the chemical equation for photosynthesis :

What Are The Two Types Of Autotrophic Bacteria

Examples of Autotrophs

How autotrophic bacteria make food? Depending on the types of sources utilized, autotrophic bacteria are categorized into two types. The two different types of autotrophic bacteria are:

  • or photosynthetic. They derive energy from sunlight.
  • Chemoautotrophs or chemosynthetic. They use chemical energy to prepare their food.
  • Apart from energy requirements, both types of bacteria need a carbon source to synthesize their food, e.g. carbon dioxide and other compounds.

    to get MCQs on Morphology of Bacteria

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    What Are Some Examples Of Autotrophs

    Other kinds of autotrophs include algae and most species of seaweed, as well as several species of bacteria and fungi. Green algae, seaweed, and some bacteria practice photosynthesis in the same way that plants do. Plants achieve this through a green pigment called chlorophyll, which is also what gives plants and certain types of algae their distinctive greenish tint.

    According to the National Ocean Service, phytoplankton are also considered autotrophs. These tiny plant-like organisms live in the ocean and are fed upon by jellyfish, shrimp, snails, and other marine creatures. They are basically microscopic marine algae, invisible to the naked eye, and floating nearest to the waters surface so they can feed upon the penetrating sunlight.

    Autotrophs In The Food Chain

    • Autotrophs form the first trophic level of the ecological food chains. Autotrophs are termed producers as these produce the food and energy, which is then transferred to the organisms present in the upper trophic levels.
    • Autotrophs are the primary source of energy in all food chains that provides energy to consumers and decomposers.
    • About 10% of the energy produced by autotrophs is transferred to the next trophic level, whereas the rest is stored in the ecosystem.
    • Autotrophs form the largest trophic level in the ecological pyramid in terms of biomass as well as energy.
    • Autotrophs are directly consumed by primary consumers, resulting in the transfer of energy. The energy then slowly moves through the chain to finally reach the apex predators.

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    Autotrophic Bacteria Types And Examples

    Oxygenic Photosynthetic Bacteria

    Cyanobacteria perform oxygenic photosynthesis. They use H2O as an electron donor and oxygen is produced in the reaction. They do not possess chloroplasts but photosynthetic pigments like chlorophyll-a are present in the cytosol.

    6CO2 + 12H2O + light energy C6H12O6 + 6O2 + 6H2O

    Cyanobacteria are filamentous or colonial, they may also perform nitrogen fixation and have specialized cells for that known as heterocyst. E.g. Nostoc, Anabaena, etc.

    Anoxygenic Photosynthetic Bacteria

    Most of the photosynthetic bacteria are anoxygenic, i.e. they do not utilize water as an electron donor, instead, they use H2S, H2 or thiosulphate as reducing agent and hydrogen sources. They contain a photosynthetic pigment known as bacteriochlorophyll , which is like chlorophylls in plants.

    Examples include green sulphur bacteria, purple sulphur bacteria, purple non-sulphur bacteria, phototrophic acidobacteria and heliobacteria, FAPs .

    CO2 + 2H2A + light energy + 2A + H2O where H2A can be any electron donor, e.g. H2S, H2 etc.

    Purple sulphur bacteria

    • Chromatiaceae contains intercellular sulphur granules
    • Ectothiorhodospiraceae contains extracellular sulphur granules

    Purple non-sulphur bacteria

    They mainly use hydrogen as a reducing agent. They belong to the order Rhodospirillales.

    They are also helpful in bioremediation of heavy metals and reducing emission of greenhouse gases.

    Green sulphur bacteria

    What Are Heterotrophs

    Biology Lecture – 30 – Autotrophs vs Heterotrophs

    In a food chain, a heterotroph is a creature that consumes other species.A heterotroph is an organism that obtains energy and nutrients through the consumption of other plants or animals. The name is derived from the Greek terms hetero, which means “other,” and trophy, which means “nutrition.”

    Heterotrophs live on the second and third tiers of a food chain, which is a series of species that offer energy and nutrients to other organisms. Each food chain is divided into three trophic levels that define an organism’s position in an ecosystem. Autotrophs, such as plants and algae, occupy the first trophic level. The second level is occupied by herbivores . The third level is occupied by carnivores and omnivores . Primary consumers and secondary consumers are both heterotrophs, whereas primary producers are autotrophs.

    A detritivore is a sort of heterotrophic consumer. These organisms gain sustenance by feeding on plant and animal remnants as well as fecal waste. By recycling garbage, detritivores play a crucial part in maintaining a healthy ecology. Fungi, worms, and insects are examples of detritivores.

    Heterotrophs are divided into two types: photoheterotrophs and chemoheterotrophs. Photoheterotrophs are creatures that obtain their energy from light but must still consume carbon from other species since they cannot use carbon dioxide from the atmosphere. Chemoheterotrophs, on the other hand, obtain both energy and carbon from other species.

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    Making And Using Food

    The flow of energy through living organisms begins with photosynthesis. This process stores energy from sunlight in the chemical bonds of glucose. By breaking the chemical bonds in glucose, cells release the stored energy and make the ATP they need. The process in which glucose is broken down and ATP is made is called cellular respiration.

    Photosynthesis and cellular respiration are like two sides of the same coin. This is apparent from Figurebelow. The products of one process are the reactants of the other. Together, the two processes store and release energy in living organisms. The two processes also work together to recycle oxygen in Earthâs atmosphere.

    This diagram compares and contrasts photosynthesis and cellular respiration. It also shows how the two processes are related.

    6CO2 + 6H2O + Light Energy â C6H12O6 + 6O2.

    Photosynthetic autotrophs capture light energy from the sun and absorb carbon dioxide and water from their environment. Using the light energy, they combine the reactants to produce glucose and oxygen, which is a waste product. They store the glucose, usually as starch, and they release the oxygen into the atmosphere.

    Cellular Respiration

    C6H12O6 + 6O2â 6CO2 + 6H2O + Chemical Energy

    Cellular respiration occurs in the cells of all living things. It takes place in the cells of both autotrophs and heterotrophs. All of them burn glucose to form ATP.

    S Involved In Photosynthesis In Plants

    In the photosynthesis process, different parts of a plant are involved that play different roles as follows:


    They are known as the food factories of the plant. It possesses chloroplasts and with the help of photosystems it receives sunlight.

    Fig: Leaves


    It is located in the epidermis of leaves mainly and helps in the exchange of gases. It takes in carbon dioxide from the atmosphere for photosynthesis and allows the exit of oxygen which is formed as a byproduct in photosynthesis.

    Fig: Structure of stomata


    They absorb water and minerals from the soil and transfer them to various plant components like leaves, stems, flowers etc.

    Fig: Absorption of water by roots

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    B Green Sulfur Bacteria

    • Green sulfur bacteria are microorganisms that are strictly anaerobic, photoautotrophs that assemble carbon compounds by utilizing sulfur compounds as electron donors.
    • The photosynthetic center of these bacteria is similar in structure and function to the photosystem of plants and cyanobacteria.
    • The light-induced electron transfer in green sulfur bacteria is non-cyclic which results in the generation of NADPH.
    • The green sulfur bacteria live in sulfur-rich environments with low-light intensities. In order to capture enough light, these have an extensive antenna system so as to capture all available photons.
    • Unlike photosynthesis in green plants, photosynthesis in green sulfur bacteria doesnt produce oxygen.

    Cultivated Magnetotactic Bacteria In Pure Culture

    The autotrophic mode of nutrition requires aCarbon class 11 biology CBSE

    Magnetospirillum species are facultatively anaerobic microaerophiles that show varying tolerances to oxygen. They are chemoorganoheterotrophs that use organic acids as a source of electrons and carbon but the gene for ribulose-1,5-bisphosphate carboxylase/oxygenase, a key enzyme of the CalvinBensonBassham cycle for autotrophy, is present in some species. In addition to oxygen, they can use nitrate as a terminal electron acceptor. This genus is phylogenetically affiliated with the alpha-subgroup of Proteobacteria. Thus far, there are only three validly described species of Magnetospirillum: M. magnetotacticum strain MS-1, M. griphyswaldense strain MSR-1, and M. magneticum strain AMB-1. All strains biomineralize cubo-octahedral crystals of magnetite. Other representatives of Magnetospirillum have been isolated from various aquatic environments. Those include seven strains isolated from a freshwater pond in Iowa, USA, and strain WH-1, isolated from sediments in North Lake, located in Qingshan, Wuhan, China. Interestingly, several related nonmagnetotactic spirilla with 95% 16S rDNA sequence similarity have also been isolated. Tractable genetic systems have been developed for M. gryphiswaldense and M. magneticum.

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    Contrasting Homeostasis In Plants And Animals

    Autotrophs rely on either light or chemical energy to turn CO2 into organic carbon molecules. Photoautotrophs are photosynthesizing organisms such as algae and higher plants that use light for this process. Heterotrophs, in contrast, obtain their chemical energy from preexisting organic molecules. Examples of heterotrophs include bacteria, which absorb organic substances from their surroundings, and many different animals, which consume and digest other organisms. These two major contrasting nutritional strategies of autotrophy and heterotrophy also contrast in their stoichiometric flexibility. Autotrophs obtain carbon, energy, and nutrients from different, somewhat independent sources, whereas many heterotrophs obtain all of these at once from the same food parcels. This contrasting flexibility in turn has a great bearing on the specifics of how stoichiometry enters into ecology.

    Autotroph nutrient content is related to growth rate . A quota is the mass or molar quantity of nutrients per cell . In unicellular autotrophs, the cell quota concept relates these two variables. The quota of the element that regulates growth rate will be very tightly related to growth rate by a relationship referred to as the Droop formula:

    where is a theoretical maximum growth, never attained, associated with infinite quota, and k is the minimum quota occurring at zero growth.

    D.R. Strong, in, 2008

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