Chapter 31: Fungi Flashcards Preview

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Flashcards in Chapter 31: Fungi Deck (24)
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1

Kingdom Fungi

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

2

Body Structure

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

3

Hyphae

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

4

Haustoria

  • are specialized hyphae
  • used to extract/exchange nutrients

5

Mycorrhizae

  • 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

6

Reproduction

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

7

Sexual Reproduction

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

8

Asexual Reproduction

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

9

Fungi History

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

10

Fungi Origin

 

  • Ancestor possibly single-celled protists

11

​Fungi Diversity

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

12

Chytrids

  • 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

13

Zygomycetes

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

14

Glomeromycetes

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

15

Ascomycetes

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

16

Basidiomycetes

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

17

Ecological Roles

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

18

Decomposers

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

19

​Mutualists

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

20

Plant Association

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

21

Animal Association

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

22

​Lichens

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

23

Parasites

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

24

Practical Uses

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