Intro to fungi

Question 1

importance of fungi

Answer 1

-decompose dead organics
-over 5000 species attack crops, while others can survive sub-zero of high temps
-many are toxic or cause disease
-yeast used in foods, penicillin for medicine, other antibiotics
-

Question 2

endophytes

Answer 2

-symbiotic fungus that lives in leaves and stems of plants, and produce toxic metabolites that protect the plant against pathogenic fungi and grazing animals

Question 3

six groups of fungi

Answer 3

• microsporidia
• chytrids
• zygomycetes
• glomeromycota
• ascomycota
• basidiomycota

Question 4

hyphae

Answer 4

• fungal filaments that make up the majority of fungi’s structure
• growth occurs and the tips, though proteins are produced throughout the mycelium
• divided by septa

Question 5

mycelium

Answer 5

-a mass of hyphae

Question 6

septa

Answer 6

• cross walls that divide hyphae

- hyphae with septa are referred as being “septate”

Question 7

yeasts

Answer 7

• unicellular, reproducing by fission or budding
• not a taxonomic group, but a morphological growth form
• are not filamentous, nor have hyphae
• obtain energy mainly through fermentation, producing ethyl alcohol from glucose

Question 8

fungal cell walls differ from plant and protists in that…

Answer 8

• they are made of chitin, not cellulose

- chitin is more resistant to microbial degradation than cellulose

Question 9

relationship of fungus body size and environment

Answer 9

-surface-volume ratio is very high, so no body part is more than a few micrometers from its external environement

Question 10

heterotrophic absorbers

Answer 10

• fungi secrete enzymes onto food source and then absorb smaller molecules that are released
• absorb food mostly at or near growing tips of hyphae
• fungi can be saprotrophs, living off dead organisms, or parasites, or symbiont

Question 11

rhizoids

Answer 11

-specialized hyphae that anchor fungi to their food source

Question 12

haustoria

Answer 12

-special hyphae that absorb nutrients directly from cells of other organisms

Question 13

mitosis and meiosis in fungi

Answer 13

• unique from plants animal and protists
• nuclear envelope does not disintegrate and reform, but is constricted in the middle between the two daughter nuclei
• in most, they use spindle pole bodies instead of centrioles, which form within the cytoplasm and move into the nucleus

Question 14

spores of (a)sexual reproduction

Answer 14

• spores may be non-motile: being dry, sticky, or fired ballistically
• bright colours and textures and usually due to spores

Question 15

sexual reproduction phases

Answer 15

-3 phases: plasmogamy, karyogamy, and meiosis

Question 16

plasmogamy and karyogamy

Answer 16

• are phases of fertilization
• plasmo. is the fusion of protoplasts
• karyo=fusion of nuclei
• karyo may not occur after plasmo for many months, leaving a dikaryon (two nuclei), which will eventually fuse into a diploid nucleus, which becomes haploid after meiosis

Question 17

gametangium

Answer 17

• gamete producing structure

- meiosis in fungi is also zygotic, as meiosis follows formation of the zygote nucleus

Question 18

sporangia and conidia

Answer 18

• asexual reproductive spores

- some fungi reproduce asexually through fragmentation of their hyphae

Question 19

budding

Answer 19

-common asexual repro. in yeasts