KINGDOM FUNGI REVISION NOTES

FUNGI

·        Fungi Constitute A Unique Kingdom Of Nucleated, Spore-Bearing, Achlorophyllous Thallophytes. These Includes The Yeasts, Moulds, Mushrooms, Puffballs, Rusts And Smuts, Morels, etc.

·        These Are Saprophytic And Ingestive In Their Mode Of Nutrition. They Do Not Synthesis Their Own Food. Thus All Fungi Ate Heterotrophic And Holozoic Like Animals. They Can Also Be Parasitic On Plants And Animals.

·        Each Cell Of Hyphae Has Chitinous Cell Wall And Glycogen As Reserve Food Material. A Few Group Of Fungi Such As Oomycetes Have Cellulosic Cell Wall Like Plants.

·        Plant Body Of Fungi Is Multicellular And Thalloid, i.e. Distinct Roots, Stems, Leaves (Or) Any Other Parts Are Absent.

·        Thallus Consists Of Tubular Filaments Called Hyphae Which Are Aggregated To Form Mycelium. The Hyphae May Be Coenocytic (Or) Uninucleated, Septate (Or) Aseptate, Primary (Or) Secondary (Or) Tertiary.

·        Fungi May Reproduce Vegetatively, Asexually (Or) Sexually.

·        Vegetative Fungi May Reproduce By Fragmentation, Fission, Budding, Oidium Formation (Or) Chalamydospore Formation.

·        Fungi Reproduce Asexually By Sporangiospores, Zoospores, Aplanospores, Conidiospores (Or) Binucleated Spores.

·        Sporangiospores Are Characteristic To Zygomycetes. These Are Produced On Aerial Hyphae Sporangiospore Inside Aa Vesicle Sporangium. They Are Thick Walled And Non-Motile.

·        Conidiospores Are Characteristic Spores Formed In Ascomycetes. These Are Produced Exogenously On The Tips Of Conidiospores, i.e. Special Aerial Hyphae.

·        Binucleated Spores These Are Mainly Formed In Basidiomycetes. They Possess Two Nuclei Coming From Two Different Hyphae, e.g. Aecidiospores, Uredospores And Teliospores.

·        Sexual Reproduction In Fungi Involves Plasmogamy, i.e. Fusion Of Protoplasts, Karyogamy, i.e. Fusion Of Nuclei To Form Zygote And Zygotic Meiosis, i.e. Division Of Zygote To Form Haploid Spores.

·        Plasmogamy May Occur via Planogametic Copulation, i.e. Fusion Of Motile Gametes, Gametangial Contact, i.e. Fusion Of Hyphae Acting As Gametangium, Gametangial Copulation, i.e. Direct Fusion Of Male And Female Gametangia, Spermatization, i.e. Sexual Fusion Between Spermatia And Female Receptive Hyphae, Somatogamy, i.e. Fusion Of Two Vegetative Cells.

·        The Sexual Spores In Fungi Can Be Basidiospores (e.g. Basidiomycetes), Ascospores, (e.g. Ascomycetes), Zygospores (e.g. Zygomycetes) And Oospore (e.g. Oomycetes)

·        Classification Of Fungi Is Based On Their Morphology Of The Mycelium, Mode Of Spore Formation And Fruiting Bodies. This Divides The Kingdom-Fungi Into Phycomycetes, Ascomycetes, Basidiomycetes And Deuteromycetes. Phycomycetes Is Further Divided Into Oomycetes And Zygomycetes.

·        Oomycetes (The Algal Fungi) Most Of Them Are Parasites. Their Thallus May Be Unicellular Of Filamentous. The Filamentous Forms Are Coenocytic And Aseptate. They Derive Their Nutrition From Host With The Help Of Haustoria. Asexual Reproduction Takes Place By Bifilgellated Zoospores. The Members Of This Group Shows Oogamous Type Of Sexual Reproduction, e.g. Phytophthora infestans (Cause Late Blight Of Potato) And Albugo candida (Causes White Rest Of Curcifers), etc.

·        Zygomycetes (The Conjugation Fungi) The Members Of This Group Are Terrestrial. They Live In Soil, Dung (Or) On Decaying Plant And Animals Matter. Their Thallus Is Coenocytic And Filamentous And Aseptate. Their Sexual (Or) Asexual Cells Do Not Have Flagella, Thus Are Completely Non-Motile. They Reproduce Asexually With The Help Of Sporangiospores And Sexually By Gametangial Copulation (Or) Conjugation, e.g. Rhizopus, Mucor, etc.   

·        Ascomycetes (The Sac Fungi) Their Thallus Is Unicellular In Yeast. While Other Fungi Of This Group Are Filamentous Having Septate Uninucleate Mycelium.

·        These Fungi Have A Sac-Like Structure Termed As Ascus. Thus Called Sac-Fungi. This Ascus Is The Product Of Sexual Reproduction. Motile Structures Are Absent In Their Life Cycle.

·        Asexual reproduction occurs with the help of conidiospores and sexual reproduction occurs by gametangial contact, conjugation, spermatization (or) somatogamy. It leads to formation dikaryotic hyphae that produce ascus in which ascospores are produced endogenously. Ascus are produced in fruiting bodies, i.e. ascocarp

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