Kornitzer Mycology

Front 1

What are the 2 basic forms of fungi?

Back 1

Molds and Yeasts

Molds - cells have the form of branching filaments (hyphae)

Yeasts - single round, oval or elongated cells. Multiply by budding or sometimes binary fission. Can form chains (pseudohyphae)

Front 2

What is an aggregated mass of hyphae called?

Back 2

Mycelium

Front 3

What are the two twpe of hyphae?

Back 3

Continuous = aseptate = coenocytic

Septate - divided by septa

Front 4

What are psuedohyphae?

Back 4

chains of elongated yeast cells where the buds remain attached to the mother cells.

Front 5

What are dimorphic fungi?

Back 5

Those that can switch between yeast and mycelial forms

Front 6

What are the metabolic characteristics and requirements of fungi?

Back 6

All are chemoheterotrophs

Either saprophytic (dead organic matter) or parastic (live organic matter)

No obligate anaerobes known. Either obligate aerobes or facultative anaerobes.

pH - Usually a preference or at least resistance to acidic media

Front 7

What fungal structure is able to mechanically puncture a plant cell?

Back 7

Appressorium

Front 8

What does an Appressorium do?

Back 8

It is a fungal structure that is able to mechanically puncture a plant cell

Front 9

How do fungi utilize polymers and carbohydrates in their surroundings?

Back 9

Secrete enzymes extracellularly, then uptake broken down products

Front 10

How is growth rate determined for fungi?

Back 10

Generation time most efficiently measured in the yeast form. Doubling time anywhere from 1-20 hours.

For molds, growth can be measured as elongation rate of hyphae, or branching rate of hyphae.

Front 11

Where does hyphae growth occur?

Back 11

Most growth occurs at tips, leaving the old mycelium empty

Front 12

How does fungal sexual reproduction occur?

Back 12

In Yeasts and Molds

Yeasts - budding or fission
Molds - formation of conidia (spores)

Front 13

What are the types of spores formed in fungi asexual reproduction?

Back 13

Sporangiospores - free cells formed inside a sporangium

Conidia (or blastic Conidia) - spores which bud out of the hyphae. Often, the conidia are formed on specialized structures called conidiophores

Arthroconidia (thallic conidia) - formed by fragmentation of pre-existing hyphae

Front 14

What are the types of arthroconidia?

Back 14

Enteroarthric - every other spore segment forms, and every other space between them is a ghost

Holoarthric - every spore segment forms

Front 15

What are the types of sexual reproduction between fungi called, and what steps does it involve?

Back 15

Heterothallic - gametes of different individuals fuse

Homothallic - gametes of the same individual fuse

Steps are:
1) Plasmogamy - fusion of 2 cells
2) Karyogamy - fusion of the 2 nuclei
3) Meiosis - reduction division

Following meiosis, individual nuclei are incorporated into sexual spores

Front 16

What is the main taxonomic classificaiton of fungi based upon?

Back 16

The morphology of the structure which supports sexual spores.

Front 17

What are the 4 phyla of "higher" fungi?

Back 17

Zygomycota - produce zygospores which result from fusion of two gametangia

Ascomycota - produce ascospores in a "bag" (ascus)

Basidiomycota - produce basidiospores, which are borne on a basidium

Deuteromycota - no known sexual cycle. Not a real taxanomic class

Front 18

What is the difference between homothallic and heterothallic fungi?

Back 18

Homothallic fungi are able to achieve mating even between two cells or hyphae of the same colony/mycelium.

In heterothallic fungi, for mating to occur or to be productive, the cells or hyphae must come from different colonies/mycelia.