Lecture 15 Fungi

Question 1

Fungi - General Features

Answer 1

• Domain: Eukarya
• Kingdom: Fungi
• Size: From single celled yeast to 3-mile-wide honey mushroom
• Other features:
• Lack chlorophyll
• Plasma membranes
• Cell walls of chitin (polymer of NAG)

Question 2

Saprophytes Nutrition

Answer 2

-nutrients from dead organic matter

Question 3

Absorptive Nutrition

Answer 3

-Secrete enzymes, absorb nutrients

Question 4

Mycology

Answer 4

-Study of fungi

Question 5

Mycoses

Answer 5

• diseases caused by fungi

Question 6

Mycotoxicosis

Answer 6

• Poisoning by fungal toxin

Question 7

Aflatoxins

Answer 7

• Carcinogens

- Intercalate between DNA bases, cause mutations

Question 8

Ergot alkaloids

Answer 8

• LSD structure
• Cause delusions and convulsions
• Used to treat migraines and induce labor

Question 9

Fungi Distribution

Answer 9

• Mostly terrestrial, some aquatic
• Can be part of human microflora
• Can be pathogens
• can form associations
• Liches = fungi and cyanobacteria
• Mycorrhizal fungi and plants
• 80% f all land plants
• Fungus provides plant nutrient and water uptake
• Plant provides fungus carbohydrate

Question 10

Yeasts

Answer 10

Unicellular fungi

Question 11

Fungi responsible for bread, beer, wine

Answer 11

Saccharomyces cerevisiae

Question 12

Fungi responsible for Thrush

Answer 12

Candida albicans

Question 13

Molds

Answer 13

Multicellular fungi

Question 14

Hyphae

Answer 14

filaments of a mold

Question 15

Mycelium

Answer 15

mass of hyphae

Question 16

How do fungi reproduce Asexually

Answer 16

• Offspring genetically identical to parent
• 3 mechanisms
  
  • Binary Fission
  • Budding
  • Spore production
    
    • Ex: Conidiospores, Sporangiospores

Question 17

How do fungi reproduce sexually

Answer 17

• Often under stress or limiting nutrients
• Offspring genetically intermediate
• Haploid cells opposite mating types fuse
• Pheromones signal between types
• Fusion creates single hypha with 2 distinct nuclei - dikaryon
• Nuclei can fuse forming diploid zygote
• Meiosis forms haploid spores

Question 18

• Simplest fungi
• Aquatic
• Motile flagellated zoospore

Answer 18

Chytridiomycota

Question 19

Chytridiomycosis

Answer 19

massive frog deaths

Question 20

• Sexual zygospores, asexual sporangiospores

- Rhizopus - bread mold

Answer 20

Zygomycota

Question 21

• Sac Fungi - ascus

- Sexual ascospores, asexual conidiospores

Answer 21

Ascomycota

Question 22

• Histoplasmosis
• Mold spores, called conidia, inhaled
• Germinate into yeast in lung
• Yeast form grows in human macrophages

Answer 22

Ascomycota

Histoplasma capsulatum

Question 23

• White Nose Syndrome in bats
• Psychrophile
• Infects skin of hibernating bats
• Large-scale killing

Answer 23

Ascomycota

Pseudogymnoascus

Question 24

• Club fungi
• Basidum - bears sexual basidiospores

Examples:

• Mushrooms
• Cryptococcus neoformans

Answer 24

Basidiomycota

Question 25

Genus of edible mushrooms

Answer 25

Basidiomycota

Genus: Agaricus

Question 26

Genus of mushroom that has amanitin (Death angel)

Answer 26

Basidiomycota

Genus: Amanita

Question 27

Amanitin

Answer 27

peptide toxin

-Target RNA polymerase

Question 28

• Pathogen in AIDS and other immunocompromised
• Infects lung, central nervous system
• Can cross blood-brain barrier

Answer 28

Basidiomycota

Cryptococcus neoformans