Lecture 7 Fungal Phyla

Question 1

How many fungal phyla are there ?

Answer 1

5

Question 2

fungal phyla are distinguished by?

Answer 2

reproductive features

Question 3

5 fungal phylum

Answer 3

Chytridiomycota (chytrids)
Zygomycota (Zygote fungi)
Glomeromycota (arbuscular mycorrhizal fungi)
Ascomycota (sac fungi)
Basidiomycota (club fungi)

Question 4

Distinguishing feature of chytrids

Answer 4

Flagellated spores

Question 5

Distinguishing feature of zygote fungi

Answer 5

Resistant zygosporangium at sexual stage

Question 6

Distinguishing feature of glomeromycota

Answer 6

form arbuscular mycorrhizae with plants

Question 7

Distinguishing feature of ascomycota

Answer 7

sexual spores (ascospores) borne internally in sacs called asci; ascomycetes also produce vast numbers of asexual spores (conidia)

Question 8

Distinguishing feature of Basidiomycota

Answer 8

Elaborate fruiting body (basidiocarp) containing many basidia that produce sexual spores (basidiospores)

Question 9

Chytridiomycota Division

Answer 9

Mainly found in water environments.
Initially categorised within Protista.
Reclassified as a fungal group.

Question 10

Characteristics of Chytridiomycota

Answer 10

• Some species are saprobes while others parasitize protists, plants and animals
• Chitinous cell wall
• Flagellated zoospores

Question 11

Zygomycota Division

Answer 11

• Zygote fungi or bread molds.
• Fusion of “mated” hyphal strands forming a zygote.

Question 12

Characteristics of Zygomycota

Answer 12

• Hyphae lack septa
• Found in soil, water, or decaying materials.
• Asexual spores produced in sporangia.
• Sexual reproduction occurs between + and – strains, forming a 2n zygote. Zygospore lies dormant before germination.
• Meiosis occurs just before germination.
• Some species act as parasites or pathogens.

Question 13

Ascomycota Division

Answer 13

Sac Fungi: Includes unicellular yeasts and complex multicellular cup fungi.
Septated Hyphae: Hyphae are partitioned with septa.

Question 14

Characteristics of Ascomycota:
Asexual Reproduction
Sexual Reproduction
Ecological Roles

Answer 14

Asexual Reproduction:
Conidia Formation: Specialized hyphal tips produce conidia (haploid asexual spore chains).

Sexual Reproduction:
Mycelia Fusion: Haploid mycelia from different mating strains fuse.

Ecological Roles:
Act as decomposers, pathogens, and engage in symbiotic relationships, notably forming lichens.

Question 15

Basidiomycota Division

Answer 15

Known as important decomposers of wood, leaves, and plant material.

Diverse Members: Includes mycorrhiza-forming mutualists, mushroom-shaped fungi, and plant parasites (Rusts and Smuts).

Question 16

Characteristics of Basidiomycota

Answer 16

Reproductive Feature:
Dikaryotic Mycelium: Characterized by a dikaryotic mycelium that reproduces sexually via basidiocarp.

Secondary Metabolites:
Production: Known to produce various secondary metabolites.

Question 17

Development in basidiomycota 1

Answer 17

Haploid basidiospores grow into short-lived haploid mycelia: under certain conditions, plasmogamy occurs

Question 18

Development in basidiomycota 2

Answer 18

Resulting dikaryotic mycelium grows forming mycorrhiza or mushrooms (basidiocarps)

Question 19

Development in basidiomycota 3

Answer 19

Mushroom cap supports and protects gills: karyogamy in the terminal, dikaryotic cells lining the gills produces diploid basidia

Question 20

Development in basidiomycota 4

Answer 20

Resulting basidium immediately undergoes meiosis producing four haploid basidiospores

Question 21

Development in basidiomycota 5

Answer 21

Asexual reproduction less common than in ascomycetes

Question 22

Beneficial Effects of Fungi

Answer 22

– Decomposition - nutrient and carbon recycling
– Biosynthetic factories. Can be used to produce drugs, antibiotics, alcohol, acids, food (e.g., fermented products, mushrooms)
– Model organisms for biochemical and genetic studies

Question 23

Harmful Effects of Fungi

Answer 23

– Destruction of food, lumber, paper, and cloth
– Animal and human diseases, including allergies
– Toxins produced by poisonous mushrooms and within food (e.g., grain, cheese, etc.)
– Plant diseases