Chapter 17 MB

budding

(1) An asexual process of reproduction in fungi in which a new cell forms as a swelling at the border of the parent cell and then breaks free to live independently. (2) The controlled release of virus particles from an infected animal cell.

spores

(1) a reproductive structure formed by a fungus (2) A highly resistant dormant structure formed from vegetative cells in several genera of bacteria, including Bacillus and Clostridium

yeasts

(1) a type of unicellular, non-filamented fungus that resembles bacterial colonies when grown in culture. (2) A term sometimes used to denote the unicellular form of pathogenic fungi.

Cryptomycota

(Thought to be a sister group to microsporidia)

What are the conditions that promote fungal growth?

- Availability of chemical nutrients. - Oxygen: the majority of fungi are aerobic organisms, with the notable exception of the facultative yeasts, which can grow in either the presence of oxygen of under fermentation conditions. Most molds are aerobic utilizes oxygen and can detoxify it Most yeasts are facultative anaerobes utilizes oxygen but can also grow in its absence - Temperature: Most fungi grow best at about 23 deg C, a temperature close to room temperature. Notable exceptions are pathogenic fungi which grow optimally at 37 deg C, which is body temperature. Dimorphic fungi grow as yeastlike cells at 37 deg C and a mycelium at 23 deg C. Psychrophilic fungi (refers to organisms that prefer to grow at cold temperatures.) grow at still lower temperatures such as a 5 deg C found in a normal refrigerator. - pH: Many fungi thrive under mildly acidic conditions at a pH between 5 and 6. Acidic soil therefore may favor fungal turf disease in which case lie (calcium carbonate) is added to neutralize the soil. Mold contamination also is common in acidic foods such as sour cream, citrus fruit, yogurt, and most vegetables. Moreover, the acidity in breads and cheese encourages fungal growth.

Describe the characteristics and specific genera or species examples as presented in lecture of the following Fungi Phyla: Glomeromycota

- most extensive symbiosis on Earth. These fungi - represent a group of endomyocorrhizae that exist within the roots of more than 80% of the world's land plants. - Interact mutually by providing essential phosphate and other nutrients to the plant. The fungi receive needed organic compounds from the plant. Example: _______________________

How are fungi different from bacteria?

1. Fungi are eukaryotes while bacteria are prokaryotes. 2. Bacteria are single celled whereas most fungi are multicellular except for yeast. 3. The compositions within their cell walls are different. 4. Fungi are heterotrophs while Bacteria can be autotrophs or heterotrophs. 5. Bacteria have 3 distinct shapes while fungi have various shapes. 6. Bacteria reproduce sexually via binary whereas fungi are capable of reproducing both sexually or asexually.

How are fungi different from plants?

1. Fungi lack chlorophyll, while plants have this pigment. 2. Fungi cell walls contain a carbohydrate called chitin; plant cell walls have cellulose. 3. Most fungi are not truly multicellular like pants. 4. Fungi are heterotrophic, while plants are autotrophic.

decomposers

A bacterial or fungal organism that breaks down and recycles on dead or decaying matter.

mycorrhizae

A close association between a fungus and the root of many plants.

basidia

A club-like structure containing basidiospores; formed by the basidiomycetes.

Ergotism, ergot

A condition inducing convulsions and hallucinations from fungal toxins in rye.

mycoses

A disease caused by a fungus.

Zoospores

A flagellated asexual cell in the Chytridiomycota.

blastospore

A fungal spore formed by budding.

chytrids

A fungus in the phylum Chytridiomycota.

endophytes

A fungus that lives within plants and does not cause any known disease.

mitosporic fungi

A fungus without a known sexual stage of reproduction.

phallotoxins

A group of chemical compounds present in the mushroom Amanita phalloides.

Glomeromycota

A group of mycorrhizal fungi that exist within the roots of most land plants.

amatoxins

A group of toxins found in several genera of poisonous mushrooms.

sclerotium

A hard purple body that forms in grains contaminated with Claviceps purpurea.

Know the following terms as they relate to fungi: mycelium

A mass of fungal filaments from which most fungi are built.

mycelium

A mass of fungal filaments from which most fungi are built.

opportunistic

A microorganism that invades the tissues when body defenses are suppressed.

hyphae

A microscopic filament of cells representing the vegetative portion of a fungus.

dermatophytosis, dermatophytes

A pathogenic fungus that affects the skin, hair, or nails.

ascomycota

A phylum of fungi whose membrane have septate hyphae and form ascospores within saclike asci, among other notable characteristics.

zygomycota

A phylum of fungi whose membranes have coenocytic.

Chytridiomycota

A phylum of predominately aquatic fungi.

mycotoxins

A poison produced by a fungus that adversely affects other organisms.

Chitin

A polymer of acetylglucosamine units that provide ridigity in the cell walls of fungi.

ascus

A saclike structure containing the ascospores; formed by members of the ascomycetes.

Know the following types of spores: basidiospore

A sexually produced fungal spore formed by members of the basidiomycetes.

Know the following terms as they relate to fungi: zygospore

A sexually produced spore formed by members of the Zygomycota. (pointing to zygozpore)

Microsporidia

A sister group of fungi that are parasitic in protists and animals.

mushroom

A spore-bearing fruiting body typical of many members of the basidiomycetes.

aflatoxin

A tonin produced by Aspergillus flavus that is cancer causing in vertebrates.

saprobes

A type of heteroautotophic organism that feeds on dead organic matter, such as rotting wood or compost.

arthrospores

An asexual fungal spore formed by fragmentation of a septate hypha.

conidia

An asexually produced funal spore formed on a supportive structure without an enclosing sac.

lichen

An association between a fungal mycelium and and a cyanobacterium or algae.

formites

An inanimate object that carries disease organisms.

chemoheterotrophs

An organism that derives energy from organic chemicals and uses the energy to synthesize nutrients from carbon compounds other that CO2 gas.

Describe the characteristics and specific genera or species examples as presented in lecture of the following Fungi Phyla: Basidiomycota

Are a club fungi including mushrooms and puffballs. - Some form with mycorrhizae (symbiosis with plant roots). - Others are plant pathogens. - Basidia on the gills of a mushroom cap contain sexually produced basidiospores.

Know the following terms as they relate to fungi: conidiophore

As asexually produced fungal spore formed on a supportive structure without an enclosing sac.

Describe the relevance of Aspergillus species

Aspergillosis, otomycosis, flatulence, aflatoxins

Describe the characteristics and specific genera or species examples as presented in lecture of the following Fungi Phyla: Chytridiomycota

Characteristics: - predominately aquatic, not terrestrial. This means the fungi originated in water, probably from a flagellated protistan ancestor. (Have flagellated reproductive cells.) - Being aquatic, chytrids have flagellated reproductive cells called zoospores that no other fungal phylum has. - Like other fungi, chytrids have chitin strengthening their cell walls. - Move and wiggle. Example: ______________________

Describe the relevance of Claviceps purpurea

Ergotism and LSD

Describe the typical Life Cycle of a Mold. What is the general asexual sequence? What is the general sexual sequence? Note: Rhizopus, the example shown in class, exhibits a "typical" mold life cycle.

In Fungi, "spores" can be produced via mitosis (asexual) or meiosis (sexual) processes General Asexual reproduction sequence "spore": germinates into hyphae, rhizoids, and stolons sporangiophore: special hypha that bears sporangia sporangia: produces identical spores by mitosis General Sexual reproduction sequence "spore": germinates into hyphae, rhizoids, and stolons Two different mating types form gametangia gametangia (n): two fuse to form a zygospore zygospore (2n): produces sporangium via meiosis sporangia (n): in this case contains genetically different spores (n)

Know the following terms as they relate to fungi: sporangiophore

Many asexual spores develop within sacs or vessels called "sporangia". Appropriately, the spores are called ________.

What groups can fungi be classified into? (Hint: there are six)

Microsporidia, Chytridiomycota, Zygomycota, Glomeromycota, Ascomycota, Basidiomycota

What is the difference between a mold and a yeast?

Mold: a type of fungus that consists of chains of cells (multicellular) and appears as a fuzzy mass of thin filaments in culture. Yeast: (1) A type of unicellular, non-filamented fungus that resembles bacterial colonies when grown in culture. (2) A term sometimes used to denote the unicellular form of pathogenic fungi.

Basic thing that mold does

Molds often break down dead or decaying matter.

What is the significance of fungi?

Mycorrhizae: Associations between fungi and the roots of plants Lichens:Symbiotic relationship between a fungus and either an alga or cyanobacterium. Pathogenic fungi:Can infect plants and humans Toxic fungi:Some fungi can produce mycotoxins

What is a mycotoxin, what is an aflatoxin?

Mycotoxin: A poison produce by a fungus that adversely affects other organisms. Aflatoxin: A toxin produced by Aspergillus flavus that is cancer causing in vertebras.

fungi

One of the four kingdoms in the domain Eukarya; composed of the molds and yeasts.

dimorphic

Referring to pathogenic fungi that take a yeast form in the human body and a filamentous form when cultivated in the laboratory.

zygospore

Sexually produced spore formed by members of the zygomycota.

How do molds and yeasts eat?

Since they are mostly terrestrial organisms, the molds and yeasts secrete enzymes into the surrounding environment that break down (hydrolyze) complex organic compounds into simpler ones. The mycelium formed by molds represents the "feeding network" for these fungi. In some cases the mycelium can form a tremendously large surface area for nutrient absorption. For yeasts, nutrients are absorbed across the cell surface similar to the way bacterial cells obtain their nutrients.

soredia

The disseminated group of fungal and photosynthetic cells formed by a lichen.

photobiont

The photosynthetic partner in a lichen.

basidiomycota

The phylum of fungi whose members have septate hyphae and form basidiospores on supportive basidia, among other notable characteristics.

Know the following terms as they relate to fungi: sporangia

The structures in fungi in which asexual spores are formed.

conidiophores,

The supportive structures on which conidia form.

Identify the characteristics of cryptococcosis (Cryptococcus neoformans)

Transmission: Airborne yeast cells Symptoms: asymptomatic opportunistic infection leads to severe headache, still neck, paralysis.

Identify the characteristics of coccidioidomycosis (Coccidioides immitis)

Transmission: airborne arthrospores Symptoms: dry hacking cough, chest pains, high fever.

Identify the characteristics of Pneumocystis Pneumonia or PCP (Pneumocystis jiroveci)

Transmission: airborne droplets Symptoms: nonproductive cough, fever, breathing difficulty.

Identify the characteristics of histoplasmosis (Histoplasma capsulatum)

Transmission: airborne spores. Symptoms: mild influenza like illness. Can disseminate to other organs.

Identify the characteristics of blastomycosis (Blastomyces dermatitidis)

Transmission: airborne spores. Symptoms: persistant cough, chest pains, chronic pneumonia.

Do fungal cells have nucleuses?

Yes, they're eukaryotes. They also have a wide range of organelles (mitochondria, an endomembrane system, ribosomes, and a cytoskeleton.) Chitin makes up their cell walls.

Know the following types of spores: blastospore

a fungal spore formed by budding

Saccharomyces

a fungus with the ability to ferment sugars.

Know the following terms as they relate to fungi: hyphae

a microscopic filament of cells representing the vegetative portion of a fungus.

Know the following terms as they relate to fungi: chitin

a polymer of acetyl glucose units that provides rigidity in cell walls of fungi. septate: referring to the cross-walls formed in the filaments of many fungi.

mutualiasm

a symbiotic relationship between two organisms of different species that benefits both.

molds

a type of fungus that consists of chains of cells and appears as a fuzzy mass of thin filaments in culture.

Describe the characteristics and specific genera or species examples as presented in lecture of the following Fungi Phyla: Ascomycota

account for 75% of known fungi. includes: Baker's yeast. (Saccharomyces cerevisaie) The mold that produces penicillin (Penicillium chrysogenum) The fungus that produces alflatoxin (Aspergillus flavus) - The fungus that causes thrush, diaper rash, and vaginitis. (Candida albacans) - Lichens are a mutualistic association between a fungus (usually ascomycota) and a photosynthetic organism (like algae)

Describe the relevance of Aspergillus species

aflatoxin, mycoses, Beano

Know the following types of spores: arthrospore

an asexual fungal spore formed by fragmentation of a septet hypha. "spore" produced when a hypha breaks

Know the following types of spores: conidia

an asexually produced fungal spore formed on a supportive structure without an enclosing sac. naked spores on a conidiophore

Know the following terms as they relate to fungi: rhizoid

anchoring hypahe

Describe the characteristics and specific genera or species examples as presented in lecture of the following Fungi Phyla: Zygomycota

are terrestrial fungi that grow as mold on bread and produce. - During sexual reproduction they form a diploid (2n) zygospore. - Example: rhizopus.

Know the following types of spores: sporangiospore

asexual spore produced by many fungi.

sporangiaspores

asexual spore produced by many fungi.

Sexual reproduction structures

heterokaryon, dikaryotic

Know the following terms as they relate to fungi: heterotrophic

heterotrophic: an organism that requires preformed organic matter for its energy and carbon needs.

mycetism

mushroom posioning.

Describe the relevance of Amanita phalloides

mycetism

coenocytic

referring to a fungus containing no septa (cross walls) and multinucleate hyphae.

Know the following terms as they relate to fungi: coenocytic

referring to a fungus containing no septa (cross-walls) and multinucleate hyphae.

septate

referring to the cross-walls formed in the filaments of many fungi.

Know the following terms as they relate to fungi: septa

septa divide the cytoplasm into different cells

ascospores

sexually produced fungal spore formed by members of the ascomycetes.

basidiospores

sexually produced fungal spore formed by memebers of the basidiomycetes.

Asexual reproduction structures

sporangia, sporangiaspores, conidiospores, conidia, arthrospores, budding, blastospore

Know the following terms as they relate to fungi: stolon

surface hyphae

dikarya

the group of fungi containing the Ascomycota and Basidiomycota.

sporualtion

the process of spore formation. Usually occurs in structures called fruiting bodies.

sporangia

the structures in fungi in which asexual spores are formed.

mycology

the study of fungi

Identify the characteristics of dermatophytosis (tinea infections)

topics to cover include: where can it occur (tinea pedis, capitis, corporis, cruris, unguium) what can transmit it: Epidermophyton, Microsporum, Trichophyton symptoms: blister like lesions. treatment: anti-fungal medications.

Identify the characteristics of candidiasis (Candida albicans)

topics to cover include: Normal microbiota vs flourishing populations Associated diseases as presented in class. Relationship to antibiotic overuse.