Kingdom Fungi NEET Notes and MCQ

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🍄 KINGDOM FUNGI

🧫 Introduction and History

  • Mycology is the study of fungi.
  • The term “Fungi” was given by Gaspard Bauhin.
  • The Father of Mycology is Mitcheli.
  • The Father of Modern Mycology is De Bary.
  • The Father of Indian Mycology is B.B. Mundker (some references also mention E.J. Butler).
  • K.C. Mehta studied the rust of wheat and made significant contributions in fungal pathology.

🌱 General Characteristics of Fungi

  • Fungi are achlorophyllous, eukaryotic, and heterotrophic organisms.
  • They are non-vascular, non-motile, and reproduce by spores.
  • Fungi grow in warm and humid environments.
  • They are found in air, water, soil, and on decaying organic matter such as wood, bread, fruits, vegetables, leather, pickles, dung, etc.
  • They may be unicellular (yeast) or multicellular filamentous forms (moulds).
  • The fungal body is called thallus, and it is haploid (n).
  • Fungal cells possess a well-defined nucleus, membrane-bound organelles, and cell walls composed of chitin or fungal cellulose.
  • Plastids and chlorophyll are absent.
  • Stored food materials are glycogen and oils (similar to animals).
  • Most fungi are aerobic, while some are facultative anaerobes (e.g., Yeast).
  • The body of fungi (thallus) is made up of interwoven thread-like filaments called hyphae, which collectively form the mycelium.
  • Fungal mycelium may be septate or aseptate (coenocytic).
  • Septate hyphae have cross walls called septa which contain pores for cytoplasmic continuity.
  • The hyphal wall consists mainly of chitin, glucans, proteins, and lipids.
  • Fungi are non-motile, except for some forms that produce zoospores with flagella (e.g., Allomyces, Synchytrium).

🍽 Nutrition in Fungi

  • All fungi are heterotrophic, obtaining nourishment by absorptive nutrition.
  • They secrete extracellular digestive enzymes which break down complex organic compounds into simple diffusible substances that can be absorbed through the cell wall and plasma membrane.

🔸 Types of Nutrition in Fungi

  1. Saprophytic Nutrition:
    • Fungi absorb nutrients from dead organic matter, such as decaying fruits, vegetables, bread, and dung.
    • They play a vital role in decomposition and nutrient recycling.
    • Example: Rhizopus, Mucor.
  2. Parasitic Nutrition:
    • These fungi obtain food from living organisms (hosts).
    • They develop haustoria, special hyphal outgrowths that penetrate host cells to absorb food.
    • Parasites may be obligate or facultative.
    • Examples: Puccinia graminis tritici (rust of wheat), Ustilago tritici (smut of wheat).
  3. Symbiotic Nutrition:
    • Fungi form mutualistic associations with other organisms.
    • (a) Lichens: a symbiotic association between fungus and alga.
      • The fungus absorbs water and minerals, while the alga synthesizes food by photosynthesis.
    • (b) Mycorrhiza: a symbiotic association between fungal hyphae and roots of higher plants (e.g., Pinus).
      • Helps in absorption of minerals, water, and provides resistance against pathogens.
  4. Predacious (Trapping) Fungi:
    • Some fungi trap small organisms like nematodes using hyphal loops or adhesive nets.
    • Example: Arthrobotrys.

🔬 Structure of Fungi

  • The fungal body (thallus) is usually filamentous and composed of hyphae.
  • Hyphae are thread-like tubular filaments that collectively form the mycelium.
  • The cell wall of most fungi is made up of chitin (a polymer of N-acetyl glucosamine), sometimes mixed with glucans, mannans, and proteins.
  • In Oomycetes, however, the cell wall is mainly cellulosic.
  • The cytoplasm contains endoplasmic reticulum, ribosomes, mitochondria, Golgi apparatus, nucleus, and vacuoles.
  • The nucleus is small, with a distinct nuclear envelope, nucleolus, and linear chromosomes.
  • Mitochondria possess plate-like cristae (not tubular).
  • Vacuoles are usually large, filled with cell sap.
  • Pigments, when present, are not photosynthetic but are often responsible for the colour of spores or mycelium.

🧩 Types of Mycelium

  1. Aseptate (Coenocytic) Mycelium:
    • Found in Phycomycetes.
    • Lacks septa; cytoplasm is continuous and multinucleate.
    • Examples: Rhizopus, Mucor.
  2. Septate Mycelium:
    • Found in Ascomycetes, Basidiomycetes, and Deuteromycetes.
    • Septa divide the hyphae into compartments; each usually contains one or two nuclei.
    • Pores in septa allow cytoplasmic streaming.
    • Ascomycetes – septa have simple pores.
    • Basidiomycetes – septa have dolipore septa with parenthesomes.
  3. Monokaryotic and Dikaryotic Mycelium:
    • Monokaryotic (n) – primary mycelium with single nucleus per cell.
    • Dikaryotic (n + n) – secondary mycelium formed after plasmogamy; two nuclei coexist without fusion.
    • Found mainly in Basidiomycetes.
  4. Plectenchyma:
    • Hyphae become compactly interwoven to form tissue-like structures.
    • Two types:
      • Prosenchyma: loosely woven hyphae, still recognizable.
      • Pseudoparenchyma: compactly arranged, appear like parenchyma of higher plants.

⚙️ Cell Wall and Stored Food

  • Cell wall: composed of chitin (fungal cellulose), sometimes with cellulose (Oomycetes).
  • Stored food: mainly glycogen and oil globules.
  • Plastids are absent, but pigments may occur in the cytoplasm or cell wall.

🧫 Yeast – A Unicellular Fungus

  • Yeast is a unicellular, non-mycelial, eukaryotic fungus.
  • It belongs to Ascomycetes (Sac fungi).
  • Yeast cells are oval or spherical, single-celled, with a thick wall made of mannoproteins and glucans.
  • Reproduction:
    1. Vegetative: by budding or fission.
    2. Asexual: by spore formation (conidia or endospores).
    3. Sexual: under unfavourable conditions, involves plasmogamy, karyogamy, and meiosis forming ascospores.
  • Stored food: glycogen and oil droplets.
  • Nutrition: saprophytic or fermentative.
  • Importance: used in baking, brewing, and ethanol fermentation.

🔁 Life Cycles in Yeast

  1. Haplontic Type:
    • The somatic phase is haploid.
    • Zygote (2n) is the only diploid stage, which undergoes meiosis to form haploid spores.
    • Example: Schizosaccharomyces octosporus.
  2. Diplontic Type:
    • The vegetative cell is diploid, producing haploid gametes by meiosis.
    • Example: Saccharomyces ludwigii.
  3. Haplo-diplontic Type:
    • Both haploid and diploid generations alternate.
    • Haploid vegetative cells form gametes that fuse to form diploid cells, which later undergo meiosis to restore haploid condition.

🔄 Reproduction in Fungi

Fungi reproduce by vegetative, asexual, and sexual methods.

🪴 1️⃣ Vegetative Reproduction

  • Takes place by the ordinary processes of vegetative growth.
  • Types:
    1. Fragmentation:
      • Mycelium breaks into small fragments, each capable of growing into a new mycelium.
      • Common in Mucor, Rhizopus, Aspergillus.
    2. Budding:
      • Found mainly in Yeast (Saccharomyces).
      • A small outgrowth (bud) develops on the parent cell.
      • The nucleus divides mitotically and one daughter nucleus passes into the bud.
      • The bud separates and grows into a new individual.
    3. Fission:
      • The parent cell divides into two equal daughter cells.
      • Found in some Yeast species (Schizosaccharomyces).
    4. Sclerotia and Rhizomorphs:
      • Sclerotia are hard, resistant, rounded masses of hyphae which help in perennation.
      • Rhizomorphs are root-like branched structures formed by compact hyphae (seen in Armillaria).

🌿 2️⃣ Asexual Reproduction

  • Occurs by the formation of various types of spores, produced without sexual fusion.
  • Spores may be motile or non-motile, thin-walled or thick-walled.
  • They are formed inside special reproductive bodies called sporangia or on special hyphal branches known as conidiophores.

🔸 Types of Asexual Spores:

  1. Zoospores:
    • Motile spores with one or two flagella.
    • Formed inside zoosporangia.
    • Found in lower fungi (Oomycetes, Chytridiomycetes).
    • Example: Synchytrium, Allomyces, Saprolegnia.
  2. Aplanospores:
    • Non-motile spores formed within a sporangium.
    • Germinate directly to produce new mycelium.
    • Common in Mucor, Rhizopus.
  3. Sporangiospores:
    • Non-motile, formed in sporangia borne on sporangiophores.
    • Released when sporangial wall ruptures.
    • Seen in Mucor, Rhizopus, Absidia.
  4. Conidia:
    • Asexual, non-motile spores produced externally on special hyphae called conidiophores.
    • They may be unicellular or multicellular.
    • Examples: Aspergillus, Penicillium, Alternaria, Cladosporium.
  5. Oidia:
    • Formed by fragmentation of hyphae into small segments which act as spores.
    • Found in Erysiphe.
  6. Chlamydospores:
    • Thick-walled resistant spores formed during unfavourable conditions.
    • May be intercalary or terminal in position.
    • Found in Fusarium, Rhizopus, Candida.
  7. Arthrospores:
    • Formed by septation and fragmentation of hyphae.
    • Each segment acts as a spore.
    • Example: Geotrichum, Oidium.
  8. Blastospores:
    • Formed by budding of the parent cell.
    • Seen in Yeast (Candida).
  9. Oospores (asexual type):
    • Thick-walled resting spores formed by the fusion of oogonium and antheridium (seen in lower fungi; transitional form).

🌸 3️⃣ Sexual Reproduction

  • Involves fusion of two compatible nuclei (sexual fusion).
  • The process usually includes three main stages:

(i) Plasmogamy

  • Fusion of cytoplasm of two parent cells.
  • Results in dikaryotic (n + n) condition.

(ii) Karyogamy

  • Fusion of the nuclei to form a diploid zygote nucleus (2n).

(iii) Meiosis

  • Reduction division restoring haploid (n) condition.
  • Produces haploid sexual spores.

⚙️ Sexual Reproduction – Types of Gametic Union

Based on the method of gamete fusion, sexual reproduction in fungi is classified into the following types:

  1. Planogametic Copulation:
    • Involves fusion of two naked, motile gametes (planogametes).
    • Occurs in Chytridiomycetes.
    • Examples: Allomyces, Synchytrium.
  2. Gametangial Contact:
    • The male and female gametangia come into contact but do not fuse.
    • The male nucleus migrates into the female gametangium through a fertilization tube.
    • Found in Oomycetes (Albugo, Phytophthora).
  3. Gametangial Copulation:
    • Entire contents of two gametangia fuse to form a zygospore.
    • Seen in Zygomycetes (Mucor, Rhizopus).
  4. Spermatization:
    • Small uninucleate male cells (spermatia) transfer their nuclei to female receptive hyphae (trichogyne).
    • Found in Ascomycetes and Basidiomycetes (Puccinia, Neurospora).
  5. Somatogamy:
    • Fusion occurs between two somatic or vegetative cells (not gametes).
    • Common in higher fungi, especially Basidiomycetes.

🧬 Sexual Spores in Fungi

Fungal GroupSexual SporeExample
PhycomycetesZygosporeRhizopus
AscomycetesAscosporeSaccharomyces, Aspergillus
BasidiomycetesBasidiosporeAgaricus, Puccinia
DeuteromycetesAbsent (no true sexual stage)Alternaria, Cercospora

🌿 Post-Plasmogamy Stages

  • After plasmogamy, karyogamy may be delayed, resulting in a dikaryotic phase (n + n), especially in higher fungi.
  • Karyogamy and meiosis occur in specialized reproductive structures:
    • Zygosporangium (Zygomycetes)
    • Ascus (Ascomycetes)
    • Basidium (Basidiomycetes)

🔁 Life Cycle Patterns in Fungi

  1. Haplontic Life Cycle:
    • The dominant phase is haploid (n).
    • Zygote (2n) undergoes meiosis immediately to form haploid spores.
    • Example: Rhizopus, Mucor.
  2. Diplontic Life Cycle:
    • The dominant phase is diploid (2n).
    • Meiosis occurs during gamete formation.
    • Example: Yeast (Saccharomyces ludwigii).
  3. Haplo-Diplontic Life Cycle:
    • Both haploid and diploid stages alternate.
    • Seen in Yeast and some other intermediate fungi.

🧭 Classification of Fungi

The Kingdom Fungi is divided into four main classes based on:

  • Nature of mycelium,
  • Mode of spore formation,
  • Type of fruiting bodies, and
  • Nature of sexual reproduction.

The four major classes are:

  1. Phycomycetes
  2. Ascomycetes (Sac Fungi)
  3. Basidiomycetes (Club Fungi)
  4. Deuteromycetes (Fungi Imperfecti)

1️⃣ PHYCOMYCETES

  • The most primitive group of true fungi.
  • Found mostly in aquatic and damp terrestrial habitats, on decaying organic matter, or as plant parasites.
  • Mycelium is aseptate and coenocytic (multinucleate).
  • Cell wall contains chitin and cellulose.

🔸 Asexual Reproduction

  • By zoospores (motile) or aplanospores (non-motile) formed inside sporangia.
  • Spores are released and germinate to form new mycelium.

🔸 Sexual Reproduction

  • Isogamous, anisogamous, or oogamous type.
  • Fusion of gametangia leads to the formation of zygospore (thick-walled resting spore).
  • Zygospore germinates to produce new mycelium after meiosis.

🧫 Examples

  • Mucor, Rhizopus (bread moulds) – saprophytic.
  • Albugo candida – causes white rust of crucifers.
  • Phytophthora infestans – causes late blight of potato.
  • Pythium – causes damping-off in seedlings.

2️⃣ ASCOMYCETES (SAC FUNGI)

  • Includes unicellular (yeasts) and multicellular filamentous forms.
  • Commonly known as sac fungi because sexual spores are produced inside sac-like asci.
  • Found in decaying organic matter, leaf litter, or as parasites and saprophytes.

🔹 Structure

  • Mycelium is septate and branched.
  • Cell wall composed mainly of chitin and glucans.

🔹 Asexual Reproduction

  • By formation of conidia borne exogenously on conidiophores.
  • Conidia are non-motile, unicellular or multicellular, and dispersed by air.
  • Each conidium germinates to form new mycelium.

🔹 Sexual Reproduction

  • Involves fusion of two compatible hyphae (plasmogamy) → formation of ascogonium and antheridium.
  • Results in dikaryotic (n + n) cells which later form ascogenous hyphae.
  • Within the ascus, karyogamy → diploid nucleus, then meiosis → haploid ascospores.
  • Generally eight ascospores per ascus.
  • Asci are contained in fruiting bodies:
    • Cleistothecium – closed (Aspergillus, Penicillium).
    • Perithecium – flask-shaped (Claviceps).
    • Apothecium – cup-shaped (Peziza, Morchella).

🧪 Examples & Importance

  • Saccharomyces cerevisiae – yeast, used in baking and brewing.
  • Penicillium chrysogenum – produces antibiotic Penicillin.
  • Aspergillus flavus – produces Aflatoxin (poisonous).
  • Claviceps purpurea – produces LSD (Lysergic acid diethylamide).
  • Neurospora crassa – used in genetic studies (“Drosophila of plant kingdom”).
  • Morchella esculenta – edible morel mushroom.

3️⃣ BASIDIOMYCETES (CLUB FUNGI)

  • The most advanced class of fungi.
  • Includes mushrooms, puffballs, bracket fungi, smuts, and rusts.
  • Found in soil, decaying wood, and as plant parasites.

🔹 Structure

  • Mycelium is septate and branched.
  • Primary mycelium – monokaryotic (n).
  • Secondary mycelium – dikaryotic (n + n), forms main plant body.
  • Dolipore septa with parenthesomes present.
  • Clamp connections maintain dikaryotic condition.

🔹 Asexual Reproduction

  • Rare or absent.
  • When present, by conidia or oidia.

🔹 Sexual Reproduction

  • No distinct sex organs.
  • Occurs by fusion of two compatible hyphae (somatogamy) → dikaryotic cells.
  • Karyogamy and meiosis take place in basidium to form basidiospores.
  • Basidia are arranged on the gills or pores of fruiting body called basidiocarp.
  • Basidiospores germinate to form new monokaryotic mycelium.

🍄 Sub-types / Examples

  1. Mushrooms – Agaricus bisporus (edible), Amanita muscaria (poisonous Toad stool).
  2. Bracket fungi – Polyporus, Ganoderma (grow on wood).
  3. Puffballs – Lycoperdon, Clavatia (contain anticancer compound Clavatin).
  4. Rust and Smut fungi – Puccinia, Ustilago.

🧠 Important Rust and Smut Diseases

DiseaseCausal OrganismHost
Wheat RustPuccinia graminis triticiWheat & Barberry
Loose Smut of WheatUstilago triticiWheat
Smut of MaizeUstilago maydisMaize
Whip Smut of SugarcaneUstilago scitamineaSugarcane
  • In Puccinia, Aeciospores form on Berberis (alternate host).
  • Teliospores undergo karyogamy and meiosis to form basidiospores.

4️⃣ DEUTEROMYCETES (FUNGI IMPERFECTI)

  • Also known as “Imperfect Fungi” because sexual reproduction is absent.
  • Reproduce only by asexual spores – conidia.
  • Many are saprophytic, some parasitic or pathogenic.
  • Mycelium – septate and branched.
  • Show a parasexual cycle (genetic recombination without meiosis).

🔹 Asexual Reproduction

  • By conidia, formed exogenously on conidiophores.
  • Conidia may be unicellular, bicellular, or multicellular.

🔹 Sexual Reproduction

  • Absent; hence “imperfect.”
  • Genetic variation occurs through parasexual cycle, discovered by Pontecorvo & Roper.
  • Involves mitotic recombination.

🔹 Examples

  • Alternaria, Colletotrichum, Cercospora, Helminthosporium, Fusarium.
  • Cercospora personata → causes Tikka disease of groundnut.

🧩 Economic Importance

  • Some species are saprophytes, helpful in decomposition.
  • Others cause plant diseases, food spoilage, or act as human pathogens.
  • Many later reclassified into Ascomycetes or Basidiomycetes after discovery of sexual stages.

💰 Economic Importance of Fungi

Fungi have both beneficial and harmful effects on human life, agriculture, and industry.

🌿 A. Beneficial Activities of Fungi

1. In Industry

  • Fermentation: Certain fungi, mainly Yeast (Saccharomyces cerevisiae), are used for the production of alcohol, beer, and wine.
  • Aspergillus niger → produces citric acid, oxalic acid, and gluconic acid industrially.
  • Penicillium camemberti and P. roquefortii → used in the ripening of cheeses.
  • Rhizopus oryzae → used in organic acid and enzyme production.
  • Mucor, Rhizopus, Aspergillus → used in industrial fermentations for amylase, protease, and lipase enzymes.
  • Yeast → used in baking industry (for dough rising).

2. In Medicine

  • Penicillium chrysogenum → produces Penicillin, first antibiotic discovered by Alexander Fleming (1929).
  • Cephalosporium acremonium → yields Cephalosporin antibiotic.
  • Streptomyces griseus (Actinomycete) → Streptomycin (though not true fungus, often associated).
  • Claviceps purpurea → produces Ergot alkaloids and LSD (Lysergic acid diethylamide) used in pharmaceuticals.
  • Aspergillus terreus → produces Lovastatin, which lowers blood cholesterol.
  • Penicillium griseofulvum → produces Griseofulvin, antifungal antibiotic.
  • Tolypocladium inflatum → produces Cyclosporin A, an immunosuppressive drug used in organ transplants.

3. In Agriculture

  • Mycorrhizae: Symbiotic association between fungal hyphae and plant roots improves water and mineral absorption.
    • Ectomycorrhiza in Pinus, Betula.
    • Endomycorrhiza (VAM – Vesicular Arbuscular Mycorrhiza) in many crop plants.
  • Biofertilizers: Fungi like Glomus, Rhizopus enhance soil fertility.
  • Biological control: Some fungi act as natural pesticides against harmful insects and nematodes.
    • e.g., Trichoderma harzianum controls soil pathogens.

4. In Food

  • Edible mushrooms: Agaricus bisporus, Volvariella volvacea, Morchella esculenta, Clavatia gigantea.
  • Protein source: Mushrooms and Yeast are rich in protein, vitamins (B-complex), and minerals.
  • Single Cell Protein (SCP): Yeast, Fusarium graminearum, and Candida utilis used for SCP production.

5. In Research and Genetics

  • Neurospora crassa → “Drosophila of plant kingdom”, used in genetic and biochemical studies.
  • Saccharomyces cerevisiae → model organism for eukaryotic cell research and molecular biology.

⚠️ B. Harmful Activities of Fungi

1. Plant Diseases (Phytopathogenic Fungi)

DiseaseCausal OrganismHost Plant
Late blight of potatoPhytophthora infestansPotato
White rust of crucifersAlbugo candidaMustard, Cabbage etc.
Loose smut of wheatUstilago triticiWheat
Red rot of sugarcaneColletotrichum falcatumSugarcane
Tikka disease of groundnutCercospora personataGroundnut
Rust of wheatPuccinia graminis triticiWheat and Barberry
Wilt of cottonFusarium oxysporumCotton
Blast disease of ricePyricularia oryzaeRice
Early blight of potatoAlternaria solaniPotato
Downy mildew of grapesPlasmopara viticolaGrapevine
  • These diseases reduce crop yield and cause economic losses to farmers.

2. Animal and Human Diseases

  • Dermatomycoses (Skin infections):
    • Trichophyton, Microsporum, Epidermophyton → Ringworm, Athlete’s foot, Tinea.
  • Candidiasis: caused by Candida albicans (yeast-like fungus); affects mouth, vagina, and internal organs.
  • Aspergillosis: caused by Aspergillus fumigatus, infection of lungs.
  • Histoplasmosis: caused by Histoplasma capsulatum; fungal infection of lungs (similar to TB).
  • Mycetoma: chronic fungal infection of skin and bones (Madurella mycetomatis).
  • Aflatoxicosis: food poisoning caused by Aflatoxin produced by Aspergillus flavus.

3. Food Spoilage

  • Fungi grow on stored food items like bread, fruit, pickles, grain, and vegetables, causing decay.
  • Rhizopus, Mucor, Penicillium, Aspergillus cause discoloration and off odours.

4. Toxic Effects (Mycotoxins)

  • Aspergillus flavus → Aflatoxin (hepatotoxic & carcinogenic).
  • Claviceps purpurea → Ergot alkaloids, cause Ergotism (convulsions, hallucinations).
  • Fusarium species → Fumonisins and Trichothecenes (mycotoxins in grains).

5. Material Destruction

  • Fungal growth damages paper, cloth, leather, wood, paints, and rubber goods in damp conditions.
  • Aspergillus niger and Mucor species are commonly responsible.

🧩 C. Ecological Role of Fungi

  • Fungi are important decomposers in nature.
  • They break down dead organic matter → release carbon, nitrogen, and minerals back to soil and atmosphere.
  • Help maintain ecological balance and nutrient cycling.
  • Form symbiotic associations like Lichens and Mycorrhizae.

Practice Questions

  1. The primary classification of fungi into Zygomycetes, Ascomycetes, and Basidiomycetes is based on reproductive features.
    The type of spores and fruiting structures distinguish them.
    (a) Reproductive spore morphology is the chief criterion in fungal taxonomy.
    (b) All fungi reproduce identically.
    (c) Classification depends on leaf type.
    (d) It’s based on chlorophyll pigment.
    Answer: (a)

    2. Fungi and actinomycetes are both decomposers but differ structurally.
    The former are eukaryotic with chitin walls, while the latter are filamentous prokaryotes.
    (a) Actinomycetes resemble fungi morphologically but are bacterial in nature.
    (b) Actinomycetes are eukaryotic molds.
    (c) Fungi lack nuclei.
    (d) Both groups are photosynthetic.
    Answer: (a)

3. Lichens demonstrate perfect physiological cooperation between two unrelated organisms. This association has allowed colonization of some of Earth’s most inhospitable habitats.
(a) The algal component provides carbohydrates while the fungal component provides structure and moisture retention.
(b) The fungus is parasitic on the alga.
(c) The alga digests the fungal hyphae.
(d) Both depend on bacteria for food.
Answer: (a)

4. In fungi, plasmogamy and karyogamy do not always occur simultaneously. This temporal separation leads to the establishment of a prolonged dikaryotic phase.
(a) The delay between cytoplasmic and nuclear fusion promotes genetic recombination.
(b) Both events always coincide.
(c) The process is exclusive to bacteria.
(d) It occurs during mitosis.
Answer: (a)

5. Fungal spores are highly resistant structures enabling survival through adverse conditions. Their dispersal ensures wide colonization, enhancing ecosystem resilience.
(a) Spores act as reproductive and survival structures produced sexually or asexually.
(b) They are formed only during meiosis.
(c) Spores lack cell walls and die quickly.
(d) Only aquatic fungi produce spores.
Answer: (a)

6. Fungal mycelium enables efficient exploration of substrates. This extensive surface area maximizes absorption efficiency.
(a) Hyphal branching increases absorptive capacity.
(b) Mycelium is used for locomotion.
(c) Hyphae are photosynthetic filaments.
(d) Mycelium stores chlorophyll.
Answer: (a)

7. The dikaryotic stage in fungal reproduction provides an evolutionary advantage. It allows recombination without immediate nuclear fusion.
(a) Two haploid nuclei coexist in one cell until karyogamy.
(b) It represents a diploid stage.
(c) It involves plasmogamy and cytokinesis simultaneously.
(d) It occurs only in yeasts.
Answer: (a)

8. The ecological role of decomposer fungi is comparable to that of bacteria but mechanistically distinct. Fungi secrete extracellular enzymes that digest complex polymers before absorption.
(a) Their hyphae release hydrolases to mineralize detritus.
(b) They directly ingest solid food particles.
(c) They photosynthesize in dark forests.
(d) They fix atmospheric nitrogen.
Answer: (a)

9. Fungi exhibit an extraordinary ability to decompose complex organic matter. This ability makes them essential components of the biosphere.
(a) Their extracellular enzymes convert complex matter into simpler forms.
(b) They depend entirely on photosynthesis.
(c) They are autotrophic.
(d) They reproduce only sexually.
Answer: (a)

10. In fungi, sexual reproduction involves three distinct stages. These include fusion of cytoplasm, nuclear fusion, and meiosis.
(a) The stages are plasmogamy, karyogamy, and meiosis.
(b) The stages are binary fission and conjugation.
(c) They reproduce only asexually.
(d) They lack nuclear fusion entirely.
Answer: (a)

11. Mycorrhizae are symbiotic associations crucial for plant survival in poor soils. The fungal partner increases nutrient absorption while the plant provides carbohydrates.
(a) They demonstrate a mutualistic relationship beneficial to both partners.
(b) They are parasitic relationships that harm the host.
(c) They involve bacterial decomposition.
(d) They occur only in algae.
Answer: (a)

12. Fungi are placed in a separate kingdom from plants because
(a) They lack chlorophyll and exhibit absorptive heterotrophic nutrition.
(b) They perform photosynthesis using bacteriochlorophyll.
(c) They store food as starch like plants.
(d) They are autotrophic in dark conditions.
Answer: (a)

13. Which of the following statements about Kingdom Fungi are correct?
(i) It includes unicellular yeasts and multicellular molds.
(ii) Fungal mycelium is made up of branched hyphae.
(iii) Most are obligate autotrophs.
(iv) Some fungi form symbiotic relationships with algae.
(a) (i), (ii), and (iv) only
(b) (ii), (iii), and (iv) only
(c) (i) and (ii) only
(d) All of these
Answer: (a)

14. Which of the following statements about Fungal Reproduction are true?
(i) Sexual reproduction involves plasmogamy, karyogamy, and meiosis.
(ii) Asexual reproduction occurs by conidia or sporangiospores.
(iii) Fruiting bodies develop during sexual reproduction.
(iv) All fungi reproduce only asexually.
(a) (i), (ii), and (iii) only
(b) (ii), (iii), and (iv) only
(c) (i) and (iii) only
(d) All of these
Answer: (a)

15. Which of the following statements about Lichens are true?
(i) They represent mutualistic association between a fungus and an alga or cyanobacterium.
(ii) The alga provides food by photosynthesis while the fungus offers water and protection.
(iii) They are resistant to air pollution and thrive in industrial areas.
(iv) They act as pioneers in rock colonization and soil formation.
(a) (i), (ii), and (iv) only
(b) (ii), (iii), and (iv) only
(c) (i) and (iii) only
(d) All of these
Answer: (a)

16. Which of the following statements about Fungi are correct?
(i) Their cell walls contain chitin and glucans.
(ii) They show absorptive heterotrophic nutrition.
(iii) Some are symbiotic while others are saprophytic or parasitic.
(iv) They are capable of photosynthesis.
(a) (i), (ii), and (iii) only
(b) (ii), (iii), and (iv) only
(c) (i), (iii), and (iv) only
(d) All of these
Answer: (a)

17. Which of the following statements about fungal reproduction are correct?
(i) Fungi reproduce vegetatively, asexually, and sexually.
(ii) Asexual spores include conidia and sporangiospores.
(iii) Sexual reproduction involves fusion of two nuclei.
(iv) All fungi reproduce through budding.
(a) (i), (ii), and (iii) only
(b) (ii), (iii), and (iv) only
(c) (i) and (iii) only
(d) All of these
Answer: (a)

18. Which of the following statements about Kingdom Fungi are correct?
(i) They are eukaryotic and heterotrophic.
(ii) They reproduce only asexually.
(iii) Their cell walls contain chitin.
(iv) They store food as glycogen.
(a) (i), (iii), and (iv) only
(b) (ii) and (iv) only
(c) (i) and (ii) only
(d) All of these
Answer: (a)

19. Which of the following statements regarding Lichens are true?
(i) They represent symbiosis between alga and fungus.
(ii) The algal partner provides food through photosynthesis.
(iii) The fungal partner provides protection and water absorption.
(iv) They cannot grow in unpolluted air.
(a) (i), (ii), and (iii) only
(b) (ii), (iii), and (iv) only
(c) (i) and (iv) only
(d) All of these
Answer: (a)

20. Which of the following are characteristic features of Fungi?
(i) Cell wall made of chitin.
(ii) Store food as starch.
(iii) Absorptive mode of nutrition.
(iv) May be saprophytic or parasitic.
(a) (i), (iii), and (iv) only
(b) (ii) and (iv) only
(c) (i) and (ii) only
(d) All of these
Answer: (a)

21. Saprophytic fungi are vital in nutrient cycling as they convert dead biomass into simple minerals usable by plants.
Their extracellular enzymatic activity drives decomposition in all ecosystems.
(a) They perform photosynthesis.
(b) They feed on living tissues.
(c) They decompose dead matter to recycle nutrients.
(d) They fix atmospheric nitrogen.
Answer: (c)

22. In fungi, the dikaryotic condition plays a crucial role in their life cycle. It represents a transitional stage where two haploid nuclei coexist in the same cell before fusion.
(a) Dikaryotic cells contain two diploid nuclei.
(b) It allows genetic recombination without immediate fusion.
(c) It is characteristic of algae.
(d) It occurs only in yeast.
Answer: (b)

23. Assertion (A): Aspergillus contamination of stored grains leads to production of aflatoxins.
Reason (R): These mycotoxins are secondary metabolites harmful to animals and humans when ingested.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a)

24. Assertion (A): Yeast is a unicellular member of Kingdom Fungi.
Reason (R): It reproduces asexually by budding and sexually by forming ascospores within asci.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a)

25. Assertion (A): Many fungal pathogens of crop plants produce toxic secondary metabolites during storage that damage crops and pose health risks.
Reason (R): Genera such as Aspergillus and Fusarium sporulate and secrete mycotoxins under warm, humid storage conditions, leading to contamination of stored grains.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Answer: (a)

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