fungi

Question 1

characteristics

Answer 1

• Eukaryotes
• Multi-cellular—yeast are unicellular
• Heterotrophs (chemoheterotrophs0
• Get nutrients from absorption
  Digest food externally via powerful hydrolytic enzymes (hydrolases)

Question 2

nutrition

Answer 2

• Parasites: feeding on living organisms
  symbionts
  by exchanging water, nutrients, and sugars with other species (plants, algae, and even animals)
  o Insects: fungi produce cellulase and enzymes and ants provide their shit and eat the fungus
  o Mutualistic

Question 3

decomposers

Answer 3

• Decompose organic material into simpler compounds that they and other organisms can absorb and metabolize
  o Decomposition recycles organic materials, releasing CO2, returning N to the soil
• ‘molds’ that are nuisances
  o Destroy fruit, wood, and human-made materials

Question 4

structure

Answer 4

• Bodies of most fungi are constructed of thread-like structures (FILAMENTS)—hyphae (string in soil)
  o Hyphae—form a interwoven mat called mycelium (A BUNCH OF HYPHAE)
   Nuclei are haploid
• All fungi have cell walls made mainly of polysaccharide chitin—in arthropods
• Septum—separates cell (CROSS WALLS)
  o lack this then its multinucleate

Question 5

asexual reproduction

Answer 5

o Sporangia—hollow structures in which spores are produced
o Conidiogenous—specialized hyphal cells which give rise to (single or chains of) spores called conidia
 Either one of these grow from haploid mycelium so spores are also haploid
DRAW

Question 6

Sexual reproduction

Answer 6

o 3 stages: gametangia, fertilization, meiosis
 Plasmogamy is the fusion of gametangia protoplasts
 Karyogamy fusion of the nuclei
o Karyogamy
 May follow plasmogamy or may be delayed, forming 2 haploid nuclei (1n+1n)
 Dikaryon (months to years can form mycelia)
 Results in formation of a diploid zygote
* Meiosis follows the haploid condition
* Fungi spend most of their life cycle in the haploid stage
* Only diploid stage in fungi is the zygote

Question 7

Chytridiomycota ‘chytids’

Answer 7

 Mostly aquatic
 Unicellular or only have rhizoids as anchor (not real roots but similar function)
 Differ from other fungi by motile zoospores and gametes
* Plant diseases like crown wart in alfalda, black wart in potatoes and brown spot in corn caused by chytrids
* Two species of chytrids have caused extinction of more 200 species of frog
* Polyphyletic groups

Question 8

Zygomycota

Answer 8

 Polyphyletic groups
 Produce thick wall sexual resting structure—zygosporangium (sporangia where zygospores are produced)
* Rhizopus stolonifera—black bread mold

Question 9

life cycle

Answer 9

 Asexual spores produced by sporangia—grow directly from haploid mycelium
 +/- gametangia fuse to form zygosporangium that can remain dormant
 Meiosis occurs, then haploid sporangium emerges from the zygosporangium to produce haploid spores that will grow into mycelium

Question 10

ascomycota

Answer 10

 Presence of an ascoma involved in sexual reproduction
 Ascomata have various shapes some are even macroscopic
 Ascoma is lined with fertile layer hymenium
* Is where asci are found
o Are sacs that house sexual spores, ascospores
o Life cycle (slide 23-25)
o
o Edible—morels and truffles
o Cause plant disease (dutch elm, disease, and chestnut blight)

Question 11

Basidiomycota

Answer 11

• Produce basidiospores on basidia (mushrooms)
• Cell division in secondary mycelium
  o Clamp connections
  o Nuclei divide by mitosis
• Basidiospores are found in hymenium
  o Hymenium (CUP) may be exposed
   Enclosed in basidioma
   Can open on it own or not
  o Basidiospores are dispersed by wind
   Are ejected or dispersed in wind by water or by insects
• Some mushrooms produce psychoactive substances to protect plant
  o Magic mushroom
  o Amanita is poisonous
• Some Basidiomycota do not form basidiomata (mushroom)
  o Smuts ad rust
   Wheat rust must infect both hosts in order to reproduce sexually (rust and shrub)
   Corn smut
• Produces black, dusty spores in place of corn kettles
   Wheat rust must infect both hosts in order to reproduce sexually (rust and shrub)
   Corn smut
• Produces black, dusty spores in place of corn kettles

Question 12

Glomeromycota

Answer 12

• Association with land plants
• Seen in 80% of plants
• Make vesicles or branching structures b/w cell wall and membrane
• Incr. yield, reduce fertilizer and protect against drought in agriculture

Question 13

Conidial fungi: Anamorphs

Answer 13

• Sexual reproduction is absent or unknown
• Some rely on conidia for propagation—ascomycetes
• Penicillin
• Trichoderma sp
  o Produces enzymes that degrade cellulose
  o Washed jean look
• Aflatoxins are secondary metabolites that cause liver cancer
• Dermatophytes cause skin disease (ring worm + athletes foot)

Question 14

Conidial fungi: Mycorrhizae

Answer 14

• Symbiotic b/w fungi and roots
• Mutualistic
  o Fungi increases plants SA for absorbing water and nutrients
   Smash ice, melt faster
   Tips roots suck water where the fungi is at
• Root hair inc. SA to suck water faster
  o Fungi gets carbs from roots
  o Fungi protects plant
• Endomycorrhizae
  o Hyphae enter into plant cell walls

Question 15

CBAGZ (FUNGI)

Answer 15

CHYTRIDS
BASDIO
ASCOMY
GLOMERO
ZYGO

Question 16

CONIDIAL FUNGI (AME)

Answer 16

ANAMORPHS
MYCORRRHIZAE
ENDOMYCORHIZAE