Chapter 23: Fungi

Question 1

Chytridiomycota (chytrid, “little pot”)

Answer 1

• Oldest
• Most unicellular
• Motile Spores-> Flagella
• Chemotaxis (movement of an organism in response to a chemical stimulus)
• Asexual

Question 2

Zygomycota (zygomycetes, “union of fungi”)

Answer 2

•Aseptate hyphae (not partitioned by septae)
•In sexual reproduction:
-(+) and (-) mating types
-fuse gametangium (sex organ)
•Plasmogamy --> dikaryote zygospore
•Karyogamy--> diploid zygospore
•Meiosis --> haploid sporangium
Asexual reproduction-mitosis

Question 3

Glomeromycota (“fungi that forms a ball”)

Answer 3

Asexual reproduction
-Walling off section of hypha–> spores
•Form mycorrhizas (fungi invades roots of plant and form a symbiotic relationship)
-symbiotic associations with plant roots -> arbuscules
-About half of fungi in soil

Question 4

ascomycetes (“skin bag”)

Answer 4

•Sac Fungi- Ascus
•Sexual reproduction
•Opposite mating types fuse
1. Plasmogamy -->Dikaryotic ascus
2. Karyogamy --> diploid zygote
3. Meiosis--> Haploid nucei->spores

Ascospores: haploid sexual spores within ascus within ascocarp
•Asexual reproduction
•haploid asexual spres (conidia) are produced on conidophores
•Yeast - budding

Question 5

Basidiomycetes (“little pedestal”)

Answer 5

Club-Shaped
Sexual
1. Plasmogamy-> Dikaryotic basidia on basiocarp
2. Karyogamy -> Diploid zygote
3. Meiosis-> 4 haploid basidiospores