Ch 29 Fungi

Question 1

Fungi are

Answer 1

Opisthokonts

Question 2

• along with animals and choanoflagellates

* based on chemical and structural characters

Answer 2

Fungi

Question 3

• Flagellate cells with single flagellum

* Plate-like cristae (inner membranes) in mitochondria

Answer 3

Derived traits of fungi:

Question 4

• Eukaryotic heterotrophs
• Secrete digestive enzymes onto food
• then absorb predigested food
• Cell walls with chitin

Answer 4

Characteristics of Fungi

Question 5

Fungi include

Answer 5

• unicellular yeasts

* filamentous, multicellular molds

Question 6

• have long, threadlike filaments (hyphae)
• branch and form a tangled mass (mycelium)
• thallus: term for a simple fungus body form

Answer 6

Most multicellular fungi

Question 7

• In most fungi (e.g. ascomycetes and basidiomycetes)
• perforated septa (cross walls) divide hyphae into
individual cells
• In some fungi (e.g. zygomycetes and glomeromycetes)
• hyphae are coenocytic (long multinuclear cell)

Answer 7

Hyphae

Question 8

Most reproduce sexually and asexually by

Answer 8

Spores

Question 9

Structure for spore production

Answer 9

Sporagium

Question 10

• generally produced on aerial hyphae for wind dispersal

* germinate into mycelium if landed in suitable spot

Answer 10

Spores

Question 11

Asexual Reproduction
• Among yeasts:
• Among molds:

Answer 11

• Budding

- Asexual spores produced through mitosis

Question 12

Sexual Reproduction
• Among yeasts:
• Among molds:

Answer 12

-uncommon
• two haploid yeasts fuse forming a zygote, which undergoes meiosis to form haploid spores
-most cells are haploid
• in most species, genetically compatible
haploid types come together in two steps
1. plasmogamy
2. karyogamy
• followed by meiosis

Question 13

• Fungi of two different mating types meet, hyphae fuse
  • cytoplasm fuses
  • nuclei remain separate
• Fungi enter dikaryotic ( n + n) stage
  • dikaryotic: having 2 nuclei per cell
  • each new cell has one nucleus of each type

Answer 13

Plasmogamy

Question 14

• Fusion of nuclei
• usually takes place in hyphal tip
• results in diploid (2 n) zygote nucleus

Answer 14

Karyogamy

Question 15

• Produce flagellate cells during life cycle
• unicellular or a few cells
• reproduce asexually and sexually
• no other fungi have flagella
• Sister to the rest of the Fungi

Answer 15

Chytrids (Chytridiomycetes)

Question 16

(e.g. black bread mold)
• Statement in the textbook:
“…members of this taxon appear most closely related to the chytrids.”
• May not be a monophyletic group

Answer 16

Zygomycetes

Question 17

(traditionally in zygomycetes or not in fungi)
• unicellular parasites
• some of the smallest known eukaryotes
• lack functional mitochondria
-have mitosomes
• highly reduced structures and genomes due to parasitism
• penetrate and infect animal cells with long, threadlike polar tubes

Answer 17

Microsporidia

Question 18

• have coenocytic hyphae
• reproduce asexually with large, multinucleate spores
• sexual reproduction has not been documented

Answer 18

Glomeromycetes

Question 19

-Important as symbionts that form intracellular associations (mycorrhizae) with plant roots
• fungus supplies water and nutrient minerals to plant
• plant secretes organic compounds needed by fungus
-Endomycorrhizal fungi
•extend hyphae into root cells (don’t break membrane)
•Arbuscular mycorrhizae
•most common endomycorrhizae
•hyphae inside root cells form branched, tree-shaped structures

Answer 19

Glomeromycetes

Question 20

Dikaryotic Fungi:

Answer 20

95% of species

Question 21

2 types of Dikaryotic Fungi are

Answer 21

• Ascomycetes- Have asci

* Basidiomycetes- Have basidia

Question 22

“sac fungi”
• Asci (microscopic “sacs”) line a fruiting body (ascocarp)
• Produce sexual spores in asci
• Hyphae have perforated septa

Answer 22

Ascomycetes

Question 23

• most yeasts
• e.g. Saccharomyces cerevisiae
• morels & truffles
• some mycorrhizae
• most lichens
• Penicillium
• ring worm (several types)
• Dutch elm disease

Answer 23

Examples of Ascomycetes

Question 24

“Club fungi”
• Basidia (club-shaped, microscopic) develop
• on surface of gills in mushrooms (basidiocarp)
• Produce sexual spores
• on outside of basidium
• Hyphae have perforated septa

Answer 24

Basidiomycetes

Question 25

* mushrooms * puffballs * bracket fungi * rusts * smuts

Answer 25

Examples of Basidiomycete

Question 26

* Mycorrhizae occur in 80% of plants. * Glomeromycetes form endomycorrhizal associations. * Ascomycetes and basidiomycetes form ectomycorrhizae with tree roots. * do not penetrate root cells

Answer 26

Ectomycorrhizae

Question 27

* 70% of all crop diseases * obtain nourishment from cytoplasm * Include * wheat rust * Dutch elm disease * Chestnut blight

Answer 27

Fungal Plant disease

Question 28

Special hyphal branches penetrate plant cells

Answer 28

Haustoria

Question 29

• Cyanobacterium or alga provides fungus with organic carbon. • Fungus provides shelter, water, minerals to autotroph. • Fungus may benefit disproportionately from the relationship. • Often the alga can live independently. • The fungus usually cannot. - Lichen names are usually based on the fungus. Lichens are able to colonize extreme habitats.

Answer 29

Lichen

Question 30

Most fungi are ____________ • break down organic compounds • many can break down plant cellulose and lignin • some contribute to digestion in ruminants (cows) • some cause wood rot damage • important for recycling elements

Answer 30

Decomposers

Question 31

Fungi are used:

Answer 31

* as foods (mushrooms, morels, truffles) * in production of beer, wine, bread (yeasts) * to produce cheeses and soy sauce * to make citric acid and other industrial chemicals

Question 32

Fungi in medicine

Answer 32

``` -Medications • Penicillin, other antibiotics -Pathogens • Superficial infections: ringworm & athlete’s foot • Internal infections: thrush & histoplasmosis ringworm -Some produce mycotoxins • 70 mushroom species • Aspergillus makes aflatoxins • grows on peanuts and corn ```