Chapter 31: Fungi

Question 1

Kingdom Fungi

Answer 1

• Heterotrophs
  
  • nutrients by absorption
• Use digestive enzyme
• 3 categories
  
  • Decomposers
  • Parasites
  • Mutualists​

Question 2

Body Structure

Answer 2

• Multicellular or unicellular (yeasts)
• made of filaments called hyphae
  
  • ​​forms network called mycelium
• cell walls made of chitin

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Question 3

Hyphae

Answer 3

• Can exist in two forms
  
  • Septate hypha
  • Coenocytic hypha

Question 4

Haustoria

Answer 4

• are specialized hyphae
• used to extract/exchange nutrients

Question 5

Mycorrhizae

Answer 5

• is a relationship between fungus and plant root
• Two types
  
  • Ectomycorrhizae
    
    • forms sheath, extend between root cells
  • Arbuscular mycorrhizae (most common)
    
    • no sheath, penetrate cell walls

Question 6

Reproduction

Answer 6

• Have sexual and/or asexual life cycles
• produces spores

Question 7

Sexual Reproduction

Answer 7

• Use sexual signals called pheromones
• Two stages
  
  • Plasmogamy - fusion of cytoplasm
  • Karyogamy - fusion of nuclei
• Forms diploid zygote, short lived
• Ends with “sexual spores”

Question 8

Asexual Reproduction

Answer 8

• Two forms
  
  • Filamentous Fungi - called molds
  • Yeasts
    
    • produce no spores
    • pinch off from parent, “budding”
• Fungi without sexual reproduction are called Deuteromycetes

Question 9

Fungi History

Answer 9

• Considered early colonizers of land
  
  • possibly predate land plants
• Symbiosis w/ early plants
• First Fossils appear 470 million years ago

Question 10

Fungi Origin

Answer 10

• Ancestor possibly single-celled protists

Question 11

​Fungi Diversity

Answer 11

• Five major groups
  
  1. Chytrids -“flagellated protists” (flagellated spores)
  2. Zygomycetes -“molds”
  3. Glomeromycetes -“mycorrhizae”
  4. Ascomycetes -“sac fungus”
  5. Basidiomycetes -“club fungus”

Question 12

Chytrids

Answer 12

• Belongs to Phylum Chytridiomycota
• common in lakes, soils
• Unique: Flagellated spores
• possible cause of global amphibian decline
  
  • fungus infects the skin of frogs destroying its structure and function

Question 13

Zygomycetes

Answer 13

• Belong to Phylum Zygomycota
• include mold, Rhizopus stolonifer
• Initiates sexual cycle under stress
  
  • produce resistant zygosporangium

Question 14

Glomeromycetes

Answer 14

• Belong to Phylum Glomeromycota
• most form arbuscular mycorrhizae
• group partnership with 80% of plants

Question 15

Ascomycetes

Answer 15

• belong to Phylum Ascomycota
• sexually produce fruiting body called ascocarp
• reproduce asexually by conidia
• include serious plant pathogens

Question 16

Basidiomycetes

Answer 16

• Belong to Phylum Basidiomycota
• Fruiting body is called basidiocarp
• long lived mycelium
• mycelium produce “fairy rings”

Question 17

Ecological Roles

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Answer 17

• 3 Major Roles
  
  1. Decomposer
  2. Mutualist
  3. Pathogens

Question 18

Decomposers

Answer 18

• Break down tough organic material
  
  • cellulose
  • lignin
• Return crucial elements to soil

Question 19

​Mutualists

Answer 19

• Form many associations
  
  • Plant - Fungus
  • Animal - Fungus
  • Lichens

Question 20

Plant Association

Answer 20

• all plants harbor fungus called endophytes
  
  • produce defensive toxins; offer resistance

Question 21

Animal Association

Answer 21

• Fungus often used for digestive services
• “farmed” by leaf cutter ants

Question 22

​Lichens

Answer 22

• association between fungus and algae
• important “pioneer” species for landscape
  
  • crucial in soil formation
• paved the way for plants

Question 23

Parasites

Answer 23

• Well known parasites include:
  
  • Plants: Chestnut blight
  • Frogs: Skin infection, massive die off
  • Humans: Athletes foot, yeast infection

Question 24

Practical Uses

Answer 24

• offer many human benefits
  
  • alcohol and bread
  • medicine : penicillin
  • food