Biological Classification: Kingdom Fungi NCERT Class XI

Characteristics Kingdom Fungi

  1. Eukaryotic organisms
  2. Heterotrophic, obtaining nutrients by absorption
  3. Cell walls composed of chitin or cellulose
  4. Reproduce via spores
  5. Include species that are decomposers, symbionts, and pathogens
  6. Some species have important roles in food production (e.g. yeast in bread making) and medicine (e.g. penicillin-producing fungi).
  7. They can be unicellular or multicellular.
  8. Some species form mutualistic relationships with plants, forming mycorrhizal associations.
  9. They are classified into different groups such as Ascomycota, Basidiomycota, and Zygomycota.
  10. They are found in almost all habitats, including terrestrial and aquatic environments.

Yeast

  1. Single-celled fungi
  2. Heterotrophic, obtain nutrients by absorption
  3. Reproduce through asexual budding or sexual reproduction
  4. Can ferment sugars, producing ethanol and carbon dioxide
  5. Used in the production of various food and beverage products such as bread, beer, and wine
  6. Can also be used in the production of biofuels and as a source of enzymes
  7. Some species have industrial and medical applications, such as in the production of antibiotics and as a model organism for genetics and biochemistry research
  8. Can exist as normal flora on human skin and in the gut
  9. Can cause infections in immunocompromised individuals
  10. Can be found in a variety of environments including soil, on plants and in the human body.

Puccinia

  1. Genus of fungi that includes rust pathogens
  2. Causes rust disease on plants, especially on cereal crops such as wheat, barley, and oats
  3. Has a complex lifecycle that involves alternating between two host plants
  4. Reproduces sexually and asexually, producing spores that can spread the disease
  5. Can cause significant yield losses in affected crops
  6. Can be controlled through the use of fungicides and resistant plant varieties
  7. Some species of Puccinia are also used in traditional Chinese medicine
  8. Puccinia species are obligate biotrophic parasites, which means they rely on living host tissue to survive and reproduce.
  9. They are considered as key pathogens that affect cereal crops worldwide.
  10. Puccinia species are classified under the phylum Basidiomycota, class Pucciniomycetes, and order Pucciniales.

Penicillium

  1. A genus of fungi that includes many species, some of which are used in the production of antibiotics such as penicillin
  2. Often found in soil and on decaying plants
  3. Can also be found in indoor environments, including on food and in the air
  4. Some species produce mycotoxins, which can contaminate food and cause illness in humans and animals
  5. Some species are used in the production of blue cheeses and as a starter culture in the fermentation of Chinese rice wine
  6. Penicillium species are important decomposers in the ecosystem
  7. Some species are used as model organisms in research on genetics, physiology, and immunology
  8. Penicillium species are classified under the phylum Ascomycota, class Eurotiomycetes, and order Eurotiales.
  9. Penicillium chrysogenum is one of the most well known species in the genus, it is the main source of the antibiotic Penicillin
  10. Penicillium species have been traditionally used in traditional medicine for centuries.

Structure of Fungi

Fungi are eukaryotic organisms that have a distinct cell structure. The main components of fungal cells include:

  1. Cell wall: made of chitin or cellulose, which provides structural support and protection for the cell.
  2. Cytoplasm: contains the cell membrane, organelles, and other cellular components.
  3. Nucleus: contains genetic material in the form of DNA.
  4. Mitochondria: organelles that produce energy for the cell.
  5. Endoplasmic reticulum and Golgi apparatus: involved in protein synthesis and transport.
  6. Vacuoles: store nutrients and waste products.
  7. Hyphae: thread-like structures that make up the body of many fungi. These can be divided into two types- septate and coenocytic.
  8. Mycelium: the mass of hyphae that make up the body of many fungi.
  9. Spores: reproductive structures that can be dispersed to colonize new areas.
  10. Some fungi have specialized structures such as fruiting bodies, which are used for sexual reproduction and spore dispersal.

The structure of a fungus can vary depending on the species and its mode of life, some fungi are unicellular while others are multicellular.

Saprophytes Fungi

Saprophytic fungi are a type of fungi that obtain their nutrients from dead organic matter. They play an important role in the decomposition of dead plants and animals, breaking down complex organic compounds into simpler compounds that can be used by other organisms.

Some characteristics of saprophytic fungi include:

  1. They are heterotrophic, obtaining their nutrients by absorption.
  2. They are found in a wide range of environments, including soil, forests, and freshwater systems.
  3. They can be decomposers of lignin, cellulose, and chitin.
  4. They are an important source of nutrients for other organisms, such as plants and animals.
  5. Many saprophytic fungi form mutualistic relationships with plants, forming mycorrhizal associations.
  6. They are an important part of the nutrient cycling process in ecosystems.
  7. Some saprophytic fungi are used for biotechnology applications, such as in the production of enzymes, antibiotics, and as bioremediation agents.
  8. They are found in many different groups such as Ascomycota, Basidiomycota, and Zygomycota.
  9. They can have diverse morphologies, ranging from single-celled yeasts to multicellular molds and mushrooms.
  10. Some saprophytic fungi are also edible and used in culinary like Agaricus and Pleurotus.

Parasites Fungi

Parasitic fungi are a type of fungi that obtain their nutrients from living organisms, causing harm to their host. They can infect a wide range of organisms, including plants, animals, and even other fungi. Some characteristics of parasitic fungi include:

  1. They are obligate or facultative parasites, which means they cannot survive without a host.
  2. They can infect their host through various means such as by direct penetration, by forming haustoria, by releasing enzymes that break down host tissue, or by forming mycorrhizal associations.
  3. They can cause a wide range of diseases, from minor leaf spots to lethal infections.
  4. They can significantly reduce the productivity and survival of their host.
  5. Some parasitic fungi are specific to a particular host or group of hosts, while others are able to infect a wide range of organisms.
  6. They can be found in many different groups of fungi, including Ascomycota, Basidiomycota, and Zygomycota.
  7. They can have diverse morphologies, ranging from single-celled yeasts to multicellular molds and mushrooms.
  8. Some parasitic fungi have evolved to produce toxins that can affect the host’s health.
  9. Control measures include the use of fungicides, resistant plant varieties, and biological control agents.
  10. Some examples of parasitic fungi are: Puccinia, Fusarium, Phytophthora, and Colletotrichum.

Symbionts Fungi

Symbiotic fungi are a type of fungi that form mutualistic relationships with other organisms, where both the fungus and the host benefit. They can be found in a wide range of environments, including soil, freshwater systems, and on the surfaces of plants and animals. Some characteristics of symbiotic fungi include:

  1. They are mutualistic, meaning that they benefit the host while also obtaining nutrients from the host.
  2. They can form mutualistic relationships with a wide range of organisms, including plants, animals, and other fungi.
  3. They can form mycorrhizal associations with plant roots, where the fungus helps the plant absorb nutrients from the soil, while the plant provides the fungus with carbohydrates.
  4. They can form lichens, which are mutualistic associations between a fungus and an alga or cyanobacterium.
  5. They can form endosymbioses with insects, where the fungus provides the insect with food and protection in exchange for a home.
  6. They can be found in many different groups of fungi, including Ascomycota, Basidiomycota, and Zygomycota.
  7. They can have diverse morphologies, ranging from single-celled yeasts to multicellular molds and mushrooms.
  8. They play an important role in nutrient cycling and ecosystem functioning.
  9. They are also used in biotechnology applications, such as in the production of enzymes, antibiotics, and as bioremediation agents.
  10. Some examples of symbiotic fungi are: Amanita, Boletus, and Tricholoma.

The Sexual Cycle of Fungi

  1. The sexual reproduction cycle of fungi involves the formation and fusion of specialized cells called gametes.
  2. In fungi, the gametes are typically haploid cells, which means they have a single set of chromosomes.
  3. The gametes are produced by a process called meiosis, in which a diploid cell undergoes cell division to produce four haploid cells.
  4. The haploid cells then undergo a process called plasmogamy, in which the cytoplasm of two different cells fuse together.
  5. This results in the formation of a diploid cell, which then undergoes meiosis to produce haploid spores.
  6. The spores can then germinate and grow into new individuals.
  7. In some fungi, the gametes are produced in specialized structures called fruiting bodies, which also help to disperse the spores.
  8. Some fungi have a heterothallic mating system, where the mating type (a or alpha) needs to be different for sexual reproduction to occur.
  9. Some fungi have a homothallic mating system, where the individual is capable of self-fertilization.
  10. The sexual reproduction cycle can also be affected by environmental factors, such as temperature, humidity, and light intensity.

Plasmogamy sexual cycle in Fungi

Plasmogamy is the process of fusion of the cytoplasm of two different cells during the sexual reproduction cycle of fungi. This process is a key step in the formation of a diploid cell, which will then undergo meiosis to produce haploid spores. Some points about plasmogamy in fungi are:

  1. Plasmogamy usually occurs between two compatible haploid cells, which are called gametes.
  2. The gametes can be produced by different individuals or by the same individual through self-fertilization.
  3. The gametes can be of the same or different mating type, depending on the fungus.
  4. The fusion of the gametes is mediated by specialized structures called gametangia or hyphae.
  5. The fusion can occur through direct contact or through the production of a bridge-like structure called a progametangium.
  6. Plasmogamy is followed by karyogamy, the process of fusion of the nuclei, which results in the formation of a diploid cell.
  7. The diploid cell then undergoes meiosis to produce haploid spores.
  8. Plasmogamy is a key step in the sexual reproduction of fungi, leading to genetic recombination and the production of genetic diversity.
  9. Some fungi have a heterothallic mating system, where the mating type (a or alpha) needs to be different for sexual reproduction to occur.
  10. Some fungi have a homothallic mating system, where the individual is capable of self-fertilization.

Karyogamy Sexual Cycle in Fungi

Karyogamy is the process of fusion of the nuclei of two different cells during the sexual reproduction cycle of fungi. This process is a key step in the formation of a diploid cell, which will then undergo meiosis to produce haploid spores. Some points about karyogamy in fungi are:

  1. Karyogamy usually occurs after plasmogamy, the process of fusion of the cytoplasm of two different cells.
  2. The nuclei of the two cells involved in plasmogamy fuse together to form a diploid cell.
  3. This diploid cell will then undergo meiosis to produce haploid spores.
  4. The spores will germinate and grow into new individuals, which can either be haploid or diploid depending on the fungus.
  5. Karyogamy is a key step in the sexual reproduction of fungi, leading to genetic recombination and the production of genetic diversity.
  6. Some fungi have a heterothallic mating system, where the mating type (a or alpha) needs to be different for sexual reproduction to occur.
  7. Some fungi have a homothallic mating system, where the individual is capable of self-fertilization.
  8. In fungi, karyogamy can occur in different ways, it can be synchronous or asynchronous, where the two nuclei fuse at the same time or at different times, respectively.
  9. Karyogamy can also occur in different location, it can happen in the same cell as plasmogamy or in different cells.
  10. The process of karyogamy is mediated by specialized structures such as the dikaryon or the clamp connection.

Dikaryotic Stage in Fungi

Dikaryotic stage is a stage in the sexual reproduction cycle of fungi, where the nuclei of the two cells that have undergone plasmogamy have not yet fused together. This stage is characterized by the presence of two genetically different nuclei in the same cell, known as dikaryon. Some points about the dikaryotic stage in fungi are:

  1. The dikaryotic stage is a temporary stage that occurs between plasmogamy and karyogamy, where the nuclei of two compatible cells remain separate.
  2. The dikaryotic stage is only found in certain groups of fungi, such as Basidiomycota and Ascomycota.
  3. During the dikaryotic stage, the two nuclei remain in close proximity and are able to exchange genetic information through a process called plasmogamy.
  4. The dikaryotic stage is a key step in the sexual reproduction of fungi, leading to genetic recombination and the production of genetic diversity.
  5. In Basidiomycota fungi, the dikaryotic stage can last for the entire life of the organism, and the nuclei only fuse during the formation of the basidiospores.
  6. In Ascomycota fungi, the dikaryotic stage can last for a shorter time, and the nuclei can fuse during the formation of the asci.
  7. The dikaryotic stage can also affect the development and morphogenesis of the fungus, for example, in Basidiomycota fungi, the dikaryotic stage is necessary for the formation of the basidiocarps (mushrooms)
  8. The process of dikaryotization is mediated by specialized structures such as the clamp connection.
  9. Some fungi have a heterothallic mating system, where the mating type (a or alpha) needs to be different for sexual reproduction to occur.
  10. Some fungi have a homothallic mating system, where the individual is capable of self-fertilization.

Important Points of sub kingdom Phycomysetes

The subkingdom Phycomycetes is a group of fungi that includes various types of aquatic and terrestrial fungi, such as water molds, downy mildews, and slime molds. Some important points about the subkingdom Phycomycetes are:

  1. Phycomycetes are a diverse group of fungi that can be found in a wide range of environments, including freshwater, marine, and terrestrial habitats.
  2. They are characterized by their aquatic or semi-aquatic lifestyle, and many are considered to be saprotrophic or parasites.
  3. They have a complex life cycle that can include both asexual and sexual reproduction.
  4. Some species are heterotrophic, obtaining their nutrients by absorbing organic matter, while others are autotrophic, obtaining their nutrients through photosynthesis.
  5. They are important decomposers in aquatic ecosystems, breaking down dead plant and animal material and recycling nutrients.
  6. Some species are important pathogens of plants and animals, causing diseases such as downy mildew and fish diseases.
  7. They play a crucial role in the functioning of aquatic ecosystems, by cycling the nutrients.
  8. They are morphologically diverse, ranging from single-celled organisms to multicellular organisms.
  9. They are classified under the phylum Oomycota and are considered to be distinct from true fungi, which are classified under the phylum Ascomycota, Basidiomycota and Zygomycota.
  10. Some examples of Phycomycetes are: Pythium, Phytophthora, Aphanomyces, Achlya and Saprolegnia.

Asexual reproduction in Phycomycetes

Asexual reproduction is a method of reproduction that occurs without the involvement of sexual reproduction in Phycomycetes. Some important points about asexual reproduction in Phycomycetes are:

  1. Asexual reproduction in Phycomycetes can occur through various methods, including fragmentation, budding, and the production of spores.
  2. Fragmentation is a method of asexual reproduction in which the organism breaks off a piece of itself, which then grows into a new individual.
  3. Budding is a method of asexual reproduction in which a small outgrowth, or bud, develops on the parent organism and eventually separates to form a new individual.
  4. Sporangiospores and zoospores are the most common spores produced by Phycomycetes, and they are produced in specialized structures called sporangia and zoospore-producing cells.
  5. Sporangiospores are formed in a sporangium, which is a reproductive structure that produces and releases spores.
  6. Zoospores are motile spores, they have flagella and are capable of swimming.
  7. Asexual reproduction in Phycomycetes is a rapid method of reproduction and allows for the rapid colonization of new environments and the spread of disease.
  8. Asexual reproduction can also occur through the production of chlamydospores, which are a type of thick-walled spores that are resistant to environmental stressors.
  9. Some species of Phycomycetes are obligate asexual reproducers, meaning they do not have a sexual stage in their life cycle.
  10. Asexual reproduction can be observed in different stages of the Phycomycetes life cycle, depending on the species and environmental conditions.

Mucor, Rhizopus and Albugo

Mucor, Rhizopus, and Albugo are all genera of fungi that belong to the subkingdom Phycomycetes, which is a group of aquatic and terrestrial fungi that includes water molds, downy mildews, and slime molds.

  1. Mucor is a genus of fungi that includes several species of molds that are commonly found in soil, rotting fruits and vegetables and other moist environments. They are known to cause human infections, particularly in immunocompromised individuals.
  2. Rhizopus is a genus of fungi that includes several species of molds that are commonly found in soil, rotting fruits and vegetables and other moist environments. Some species of Rhizopus are known to cause human infections, particularly in immunocompromised individuals. They are also used in food fermentation process.
  3. Albugo is a genus of fungi that includes several species of water molds that are commonly found in freshwater environments. They are known to cause diseases in plants, particularly in the family Brassicaceae, including cauliflower, broccoli and other cruciferous vegetables.
  4. Mucor and Rhizopus are morphologically similar and are often difficult to distinguish. Both genera have a characteristic black, branching mycelium.
  5. Mucor and Rhizopus reproduce both sexually and asexually, while Albugo reproduces asexually.
  6. Mucor, Rhizopus and Albugo are important decomposers in aquatic and terrestrial ecosystems, breaking down dead plant and animal material.

Important points of Sub Kingdom Ascomycetes

The subkingdom Ascomycetes is a group of fungi that includes various types of fungi such as yeasts, molds, and morels. Some important points about the subkingdom Ascomycetes are:

  1. Ascomycetes are a diverse group of fungi that can be found in a wide range of environments, including terrestrial, freshwater, and marine habitats.
  2. They are characterized by the production of reproductive structures called asci, which contain the sexual spores.
  3. They have a complex life cycle that can include both asexual and sexual reproduction.
  4. Some species are heterotrophic, obtaining their nutrients by absorbing organic matter, while others are autotrophic, obtaining their nutrients through photosynthesis.
  5. They are important decomposers in ecosystems, breaking down dead plant and animal material and recycling nutrients.
  6. Some species are important pathogens of plants and animals, causing diseases such as powdery mildew and apple scab.
  7. They play a crucial role in the functioning of ecosystems, by cycling the nutrients.
  8. They are morphologically diverse, ranging from single-celled yeasts to multicellular molds and morels.
  9. They are classified under the phylum Ascomycota and are considered to be true fungi.
  10. Some examples of Ascomycetes are: Saccharomyces, Penicillium, Aspergillus, Claviceps, and Morchella.
  11. Ascomycetes are known for their wide range of biotechnological applications such as the production of antibiotics, enzymes, and food and beverage products.
  12. Many species of Ascomycetes form symbiotic relationships with other organisms such as lichens, mycorrhizae and endophytes.
  13. Some species of Ascomycetes are edible and are considered as delicacies, such as morels and truffles.
  14. Ascomycetes can reproduce both sexually and asexually, depending on environmental conditions.
  15. The sexual reproduction in Ascomycetes involves the formation of asci, which contain the sexual spores.
  16. Asexual reproduction in Ascomycetes can occur through various methods, including fragmentation, budding and the production of spores such as conidia.
  17. Some species of Ascomycetes have a dikaryotic stage in their life cycle, where the nuclei of the cells remain separate for a period of time before undergoing karyogamy.
  18. Ascomycetes have a wide range of ecological roles, some are decomposers, some are parasites and some are mutualistic symbionts.
  19. As comycetes have a wide range of ecological roles, some are decomposers, some are parasites, and some are mutualistic symbionts.
  20. Many Ascomycetes have a cosmopolitan distribution and can be found on all continents, while others are restricted to specific regions or habitats.

Reproduction in Ascomycetes

Reproduction in Ascomycetes, a group of fungi that belongs to the subkingdom Ascomycota, can occur both sexually and asexually. Some important points about reproduction in Ascomycetes are:

  1. The sexual reproduction in Ascomycetes involves the formation of specialized reproductive structures called asci, which contain the sexual spores.
  2. The asci are produced in a structure called the ascocarp, which can take various forms such as cups, apothecia, or perithecia.
  3. The sexual spores, called ascospores, are formed inside the asci through a process called meiosis, which reduces the number of chromosomes by half.
  4. The ascospores are usually dispersed by wind or water and can germinate to form new individuals.
  5. Some Ascomycetes have a dikaryotic stage in their life cycle, where the nuclei of the cells remain separate for a period of time before undergoing karyogamy, which is the fusion of the nuclei.
  6. Asexual reproduction in Ascomycetes can occur through various methods, including fragmentation, budding, and the production of spores called conidia.
  7. Conidia are formed through mitosis, the process of cell division, and can be dispersed by wind or water to form new individuals.
  8. Asexual reproduction in Ascomycetes is a rapid method of reproduction and allows for the rapid colonization of new environments and the spread of disease.
  9. Asexual reproduction can also occur through the production of sclerotia, which are a type of thick-walled spores that are resistant to environmental stressors.
  10. The reproduction method of Ascomycetes can be affected by environmental factors such as temperature, humidity, and light intensity.

Sub kingdom Basidiomycetes

The subkingdom Basidiomycetes is a group of fungi that includes various types of fungi such as mushrooms, rusts, and smuts. Some important characters and the reproduction system of Basidiomycetes are:

  1. Basidiomycetes are characterized by the presence of specialized reproductive structures called basidia, which produce the sexual spores called basidiospores.
  2. Basidiomycetes typically have a complex life cycle that includes both asexual and sexual reproduction.
  3. They are typically heterotrophic, obtaining their nutrients by absorbing organic matter.
  4. They are important decomposers in ecosystems, breaking down dead plant and animal material and recycling nutrients.
  5. Some species are important pathogens of plants and animals, causing diseases such as rusts and smuts.
  6. They play a crucial role in the functioning of ecosystems by cycling the nutrients.
  7. Basidiomycetes are morphologically diverse, ranging from single-celled yeasts to multicellular mushrooms.
  8. They are classified under the phylum Basidiomycota.
  9. Some examples of Basidiomycetes are Agaricus, Amanita, Coprinus, Puccinia and Ustilago.
  10. Basidiomycetes typically have a dikaryotic stage in their life cycle, where the nuclei of the cells remain separate for a period of time before undergoing karyogamy.
  11. The sexual reproduction in Basidiomycetes involves the formation of basidia, which produce basidiospores through meiosis.
  12. Asexual reproduction in Basidiomycetes can occur through the production of a variety of spores, such as conidia, chlamydospores and sclerotia.
  13. An example of Basidiomycetes reproduction is Agaricus, the common mushroom. Agaricus reproduces sexually through the formation of basidia, which produce basidiospores. The basidiospores are dispersed by wind and can germinate to form new individuals. Asexual reproduction in Agaricus can occur through the production of chlamydospores, which are thick-walled spores that can survive in harsh conditions.
  14. Basidiomycetes are known for their wide range of biotechnological applications such as the production of enzymes, antibiotics, and food and beverage products.
  15. Some Basidiomycetes form mutualistic symbiotic relationships with plants, such as mycorrhizae, where they help the plant absorb nutrients from the soil.
  16. Basidiomycetes also have medicinal properties, some are used to treat cancer, others as immunostimulants and others as anti-inflammatory agents.
  17. Basidiomycetes can be found in a wide range of habitats, including terrestrial, freshwater and marine environments. Some species are restricted to specific regions or habitats.

Sub kingdom Deuteromycets

The subkingdom Deuteromycetes, also known as Fungi Imperfecti, is a group of fungi that includes various types of fungi that have not been observed reproducing sexually. Some important characters and the reproduction system of Deuteromycetes are:

  1. Deuteromycetes are characterized by the absence of a sexual stage in their life cycle, and therefore their classification is based on their asexual reproductive structures and features.
  2. They typically have a simple life cycle that includes only asexual reproduction.
  3. They are typically heterotrophic, obtaining their nutrients by absorbing organic matter.
  4. They are important decomposers in ecosystems, breaking down dead plant and animal material and recycling nutrients.
  5. Some species are important pathogens of plants and animals, causing diseases such as leaf spot and rot.
  6. They play a crucial role in the functioning of ecosystems by cycling the nutrients.
  7. Deuteromycetes are morphologically diverse, ranging from single-celled yeasts to multicellular molds.
  8. They are classified under the phylum Deuteromycota.
  9. Some examples of Deuteromycetes are Alternaria, Aspergillus, Fusarium and Penicillium.
  10. Deuteromycetes reproduce asexually through the production of spores such as conidia, which are formed through mitosis, and can be dispersed by wind or water to form new individuals.
  11. An example of Deuteromycetes reproduction is Penicillium, which reproduces asexually through the production of conidia.
  12. Deuteromycetes are known for their wide range of biotechnological applications such as the production of antibiotics, enzymes, and food and beverage products.
  13. Deuteromycetes can be found in a wide range of habitats, including terrestrial, freshwater and marine environments. Some species are restricted to specific regions or habitats.
  14. Despite not having a sexual stage observed, some Deuteromycetes have been reclassified into other subkingdoms such as Ascomycota or Basidiomycota, based on molecular analysis.
  15. Deuteromycetes have a wide range of ecological roles, some are decomposers, some are parasites, and some are mutualistic symbionts.
  16. Many Deuteromycetes have a cosmopolitan distribution and can be found on all continents, while others are restricted to specific regions or habitats.
  17. Deuteromycetes can be observed in different stages of the life cycle, depending on the species and environmental conditions.

The lack of sexual reproduction makes it difficult to classify and identify some species of Deuteromycetes, leading to the usage of morphological and molecular techniques.