Post on 22-Dec-2015
Fungi are NOTNOT plants Nonphotosynthetic Eukaryotes Nonmotile Most are saprobessaprobes (live on dead organisms)
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Absorptive heterotrophsAbsorptive heterotrophs (digest food first & then absorb it into their bodies
Release digestive enzymesdigestive enzymes to break down organic
material or their host Store food energy as
glycogenglycogenBREAD MOLDBREAD MOLD
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Important decomposers & recyclers of nutrients in the environment
Most are multicellular, except unicellular yeast
Lack true roots, stems or leaves
MULTICELLULAR MULTICELLULAR MUSHROOMMUSHROOM
UNICELLULAR YEASTUNICELLULAR YEAST
Cell walls are made of chitin (complex polysaccharide)
Body is called the Thallus
Grow as microscopic tubes or filaments called hyphae
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Produce both sexual and asexual spores
Classified by their sexual reproductive structures
Spores come Spores come in various in various
shapesshapes88
Grow best in warm, moist environments
Mycology is the study of fungi
Mycologists study fungi A fungicide is a chemical
used to kill fungi
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Fungi include puffballs, yeasts, mushrooms, toadstools, rusts, smuts, ringworm, and molds
The antibiotic penicillin is made by the Penicillium mold
Penicillium moldPenicillium mold
PuffballPuffball 1010
TubularTubular shape ONEONE continuous
cell Filled with
cytoplasm & cytoplasm & nucleinuclei
MultinucleateMultinucleate Hard cell wall of
chitinchitin1212
StolonsStolons – horizontal hyphae that connect groups of hyphae to each other
RhizoidsRhizoids – rootlike parts of hyphae that anchor the fungus
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STOLONSTOLON
RHIZOIDSRHIZOIDS
Cross-walls called SEPTA may form compartments
Septa have pores for movement of cytoplasm
Form network called mycelia that run through the thallus (body)
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Hyphae grow from their tips Mycelium is an extensive,
feeding part of hyphae Mycelia are the ecologically
active bodies of fungi
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ABSORPTIVE ABSORPTIVE HETEROTROPHHETEROTROPH
Fungi get carbon from organic sources
Tips of Hyphae release enzymes Enzymatic breakdown of substrate Products diffuse back into hyphae
Digested material is then used by the hyphae
Nucleus “directs” the digestive process
Fungi may be classified based on cell division (with or without cytokinesis) Aseptate or coenocytic (without
septa) Septate (with septa)
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NO CROSS NO CROSS WALLSWALLS CROSS CROSS
WALLSWALLS
REPRODUCTIONREPRODUCTION
Most fungi reproduce AsexuallyAsexually and SexuallySexually by spores
ASEXUALASEXUAL reproduction is most most common common method & produces genetically identical genetically identical organisms
Fungi reproduce SEXUALLYSEXUALLY when conditions are poor & conditions are poor & nutrients nutrients are are scarcescarce
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SPORESSPORES
Spores are an adaptationadaptation to life on land
Ensure that the species will disperse species will disperse to new locationsto new locations
Each spore contains a reproductive reproductive cellcell that forms a new organism
NonmotileNonmotile Dispersed by windwind
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SEXUAL REPRODUCTIONSEXUAL REPRODUCTION Used when environmental Used when environmental
conditions are poor conditions are poor (lack (lack of nutrients, space, of nutrients, space, moisture…)moisture…)
No male or female fungiNo male or female fungi Some fungi show Some fungi show
dimorphismdimorphism May grow as May grow as MYCELIA MYCELIA
or aor a YEAST –LIKE YEAST –LIKE state state (Filament at 25(Filament at 25ooC & C & Round at 37Round at 37ooC)C)
2121Dimorphic FungiDimorphic Fungi
SEXUAL REPRODUCTIONSEXUAL REPRODUCTION Haploid 1n hyphae 1n hyphae from 2 mating types (+ 2 mating types (+
and -) FUSE and -) FUSE (Fertilization)(Fertilization) Forms aForms a hyphae with hyphae with 2 nuclei that 2 nuclei that
becomes a ZYGOTEbecomes a ZYGOTE The zygote divides to make a The zygote divides to make a SPORESPORE
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SPORE FORMSSPORE FORMS
THREE TYPES OF ASEXUAL REPRODUCTIONTHREE TYPES OF ASEXUAL REPRODUCTION
FragmentationFragmentation – part of the mycelium becomes separated & begins a life of its own
BuddingBudding – a small cell forms & gets pinched off as it grows to full size Used by yeasts Used by yeasts
Asexual spores Asexual spores – production of spores by – production of spores by a single myceliuma single mycelium
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Spores may be Formed: Directly on hyphae Inside sporangia On Fruiting bodies
Amanita fruiting body Pilobolus sporangia
Penicillium hyphae
Fruiting Bodies Fruiting Bodies are modified as hyphae that make asexualasexual spores
An upright stalk called the SporangiosphoreSporangiosphore supports the spore case or SporangiumSporangium
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Types of Fruiting Types of Fruiting Bodies:Bodies: BasidiaBasidia SporangiaSporangia AscusAscus
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BasidiaBasidia
SporangiaSporangia
Parasitic Fungi
Cause Disease DirectlyCause Disease Directly Parasitic Fungi Actual fungal growth in
organism Cause Disease IndirectlyCause Disease Indirectly
Allergic reactions Toxin ingestionToxin ingestion
Exhibit DimorphismExhibit Dimorphism Mould form (mycelial, filamentous) Yeast form (or spherule form) Change due to temperature, nutrients, CO2
levels
Major Fila of Fungi
Chytridiomycota— sexual and asexual spores motile, with posterior flagella
Zygomycota— sexual spores are thick walled resting spores called zygospores
Ascomycota—spores borne internally in a sac called an ascus
Basidiomycota—spores borne externally on a club-shaped structure called a basidium
“deuteromycetes” or Fungi Imperfecti, have no known sexual state in their life cycle.
Superficial fungal infection
Skin infection Limited to stratum corneum Do not penetrate deeper tissues No inflammationSuperficial mycoses *Black piedra *White piedra *Pityriasis versicolor *Tinea nigra
Black piedraWhite piedra
Cutaneous mycoses
Dermatophytoses Clinical condition caused by
fungal infection of the skin in humans
Dermatomycoses Skin disease caused by a fungus
Subcutaneous mycosesSubcutaneous mycoses
Caused by trauma and introduction of the fungus and bacteria
Chromoblastomycosis Phaeohyphomicosis Mycetoma Sporothricosis
Mycetoma
Systemic mycosisSystemic mycosis
Histoplasmosis Coccidiomycosis Blastomycosis Cryptococcosis
Histoplasmosis