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Home , Asexual reproduction, Hypha

Opening Activity ☤Latin Root Word: myco - Kingdom Fungi Fungi are their own kingdom

 I. Basic Characteristics/Terminology:  : study of fungi  Eukaryotic; BOTH unicellular OR multicellular  Range in size from microscopic to LARGEST organism in the world (Armillaria)  Dimorphism: ability of fungus to change forms during cycle (ex. Histoplasma capsulatum) Basic Characteristics

 “Common” Examples: 1. : tangled masses of filaments of cells; grow on foods like breads and oranges. 2. : unicellular organisms; colonies resemble ; make breads rise. II. Basic Structures:  : substance in walls; distinguishes fungi from (cell walls of )  Hyphae: filaments of fungi  : mat of hyphae visible to unaided eye  Septa: cross sections that divide hyphae in some fungi  Coenocytic: hyphae without septa in fungi  SEE FIGURE 28-1 (p. 543) ***Bread ***

Fungi as Saprobes and Decomposers III. Feeding in Fungi:  Nonphotosynthetic  “Multicellular Heterotrophs”- Most Saprophytic  Secrete digestive enzymes as hyphae grow and encounter new organic matter.  Unlike other organisms, digest nutrients BEFORE ingesting them!!!

 ~85 billion tons of carbon as CO2 are returned to the atmosphere annually  pathogens destroy ~3 billion dollars of crops annually in N. America Fungi in History-Salem Witch Trials

 In 1692 several women in Salem, MA were accused of witchcraft and hung  Evidence suggests their “strange behavior” may have been due to poisoning by the fungus, , a pathogen of rye  This fungus produces toxins (alkaloids) that cause vasoconstriction.  It is the source of LSD  Can lead to off of the blood supply and loss of limbs due to gangrene setting in Heterotrophic by Absorption

 Fungi get carbon from organic sources  Hyphal tips release enzymes  Enzymatic breakdown of substrate  Products diffuse back into hyphae

Nucleus hangs back and “directs”

Product diffuses back into hypha and is used Hyphal growth  Hyphae grow from their tips  Mycelium = extensive, feeding web of hyphae

 Mycelia are the ecologically active bodies of fungi

This wall is rigid Only the tip wall is plastic and stretches Reproduce by  Spores are reproductive cells  Sexual (meiotic in origin)  Asexual (mitotic in origin)  Formed:  Directly on hyphae  Inside sporangia  Fruiting bodies

Penicillium hyphae with conidia Pilobolus sporangia Amanita fruiting body IV. Asexual : pg 544  : Produce and release thousands of genetically identical haploid spores.  Types of Asexual Spores/Reproduction: 1. Sporangiospores: made inside of sporangiophores; Ex. (bread fungus) 2. Conidia: spores formed without protection of enclosing sac; Ex. 1. Fragmentation: cells from septate hypha dry and shatter to act as spores; Ex. Athlete’s foot 1. : part of cell “pinches” off to produce small offspring cells; Ex. Yeast Hyphal growth from

germinating spore mycelium

 Mycelia have a huge surface area V. :

1. Occur in “plus” and “minus” mating pairs (NOT male and ) 2. Hyphae fuse in opposites of same 3. Exchange genetic material 4. Specialized structures form that produce and scatter genetically diverse spores=Fruiting Body VI. in Fungi:

 Believed to have arose, like other , by endosymbiosis.  Probably colonized dry land at about same time as early plants.  ALL THREE modern phyla of fungi are believed to have evolved by about 300 mya. Lab Observation: Bread Mold Fungus (Rhizopus stolonifer) What is the biggest organism ever?

Apatosaurus?

Blue whale? Coast redwood?

None of the above – it’s a fungus

“honey ” Armillaria can cover more than 2,200 acres (1,600 football fields) Opening Activity 6.2

 The filaments of fungi are known as…

 Latin Root Word: Rhiza - root Part 2: “Fungi and Humans”

Section 28-3 (pp. 550-552) Functional of Fungi Parasites

Ringworm

Functional Biology of Fungi Toxin producers Aflatoxin Functional Biology of Fungi Biotic control agents

The first antibiotic used by humans

Staphylococcus Penicillium

Zone of inhibited growth Functional Biology of Fungi Biotic control agents

Used against , rice weevils, etc. Functional Biology of Fungi

Interesting example… of fungal cowboys

unlucky nematode Some soil fungi snare nematode worms in hyphal nooses and then digest them fungal hypha Functional Biology of Fungi

Interesting example… of fungi & conservation

The golden toad became extinct within the past 20 years, owing to anthropogenic environmental deterioration, which also facilitated pathogenic chytrid fungi HUMAN-FUNGUS INTERACTIONS

 Beneficial Effects of Fungi  Decomposition - nutrient and carbon recycling.  Biosynthetic factories. Can be used to produce drugs, antibiotics, alcohol, acids, food (e.g., fermented products, ).  Model organisms for biochemical and genetic studies.  Harmful Effects of Fungi  Destruction of food, lumber, paper, and cloth.  and human diseases, including allergies.  Toxins produced by poisonous mushrooms and within food (e.g., grain, cheese, etc.). XIII. Fungi and Human Disease:  Mold Spores- cause mild allergies.  Fungal Skin Infections: athletes foot, ringworm  Other Fungal Illnesses: 1. Respiratory Illness: caused by H. capsulatum, P. brasiliensis, C. immitis, B. dermatittidis. 2. Liver destruction: caused by Amanita mushrooms 3. Liver Cancer: caused by aflatoxins produced by . Found in contaminated peanuts and corn. XIV. Fungi in Industry:  Penicillium- used in penicillin.  Cephalosporium-used in cephalosporin antibiotics.  Rhizopus- used in cortisone.  S. cerevisiae- yeast used to develop Hepatitis B vaccine.  Yeast also used to produce ethanol. XV. Fungi and Food Industries:

 Produce citric acids (used in soft drinks and candies)  Produces gluconic acid (fed to chickens to harden eggshells). Rhizopus

Aspergillus Penicillium Opening Activity: write on 7.1 and then turn to 6.3

 Most fungi are a. saprophytic b. Heterotrophic c. autotrophic d. Both a. & b.

 Latin Root Word: Sapro- decay Part 3: “Fungi Classification”

Section 28-2 (pp. 546-549) VII. Fungi Classification:

 Approx. 100,000 species  3 Phyla  Traditionally classified by structure and form of sexual reproduction. Fungal Life Cycles Reproduction

Asexual – default mode under stable conditions; spores are produced Fungal Life Cycles

Key Haploid (1n) spores Haploid (n) Heterokaryotic stage Heterokaryotic are produced by PLASMOGAMY (fusion of ) Diploid (2n) Spores are geneticallyKARYOGAMY (fusion of nuclei) Spore-producing structures identical to original SEXUAL Zygote REPRODUCTION Spores mycelium ASEXUAL Mycelium REPRODUCTION Spores disperse and germinate to GERMINATION produce Spore-producingnew structures Spores myceliun See Fig. 31.5 Fungal Form and Function Reproduction

Asexual – default mode under stable conditions; spores are produced

Sexual – usually only under stressful conditions; spores are produced; many mating types possible (essentially like having many different or genders)

Sexual reproduction in fungi

+ fusion of compatible hyphae – (plasmogamy) hyphae (n)

fused hyphae (n + n) dispersal of spores

+ zygote (2n) fusion of nuclei + () – – sexual spores (n) meiosis of zygotes (2n) “zygote-like” structures Sexual reproduction in fungi

Haploid spores may disperse long distances away from the fruiting body XI. Phylum :

 15,000 known species  “club” fungi  Includes Mushrooms, puff balls, and shelf fungi  Reproduce using dikaryotic structures called basidia.  See Figure 28-5 (p. 547)

Opening Activity: 7.2

 The three fungi are distinguished based on their structure and form of

 Latin Root Word: Zygon - yoke Opening Activity

 Sexual reproduction VIII. Phylum :

 Sexual Reproduction: sporangia  Asexual Reproduction: common (sporangia: bags of asexual spores)  Found in rich soils  Coenocytic hyphae (no cross-sections)  Rhizoids: hyphae that anchor mold to surface (rhiza- Greek for “root”).  : hyphae grow across surface.

X. Phylum :  Sexual reprodcution: asci/  75% of ALL fungi  “Sac” Fungi- includes baker’s yeast, morels, and truffles.  Reproduction: 1. Fruting body of fungi above ground = . 2. Reproductive structure in ascocarp = asci. 3. develop and are released.

A cluster of asci with spores inside

XI. Special Types of Fungi: 1. Deuteromycota: “fungi imperfecti;” fungi without a sexual stage; most now classified in phylum Ascomycota. 2. : symbiotic association b/t fungi and plant roots; provides phosphate to plant roots and receives sugar from of plants; many classified in phyla Zygomycota and Basidiomycota. Mycorrhizae Critical role in plant growth  extends water absorption of roots

without with mycorrhizae mycorrhizae

Endomycorrhiza : : symbiotic relationship b/t fungi and or green ; relationship decomposes rocks and helps produce soil; most classified in phylum Ascomycota. Write on 7.3 next to yesterday’s opening activity, will also need week 6.1

 ______allow fungus to reproduce and are usually released to be carried by the wind.  Latin Root Word: ultra - above XII. Types of Lichens:  Crustose: grow on rocks and .  Fruticose: shrub-like  Foliose: grow on soil surfaces.