fungi 1

Question 1

kingdom fungi

Answer 1

No chlorophyl (thus no photosynthesis)
Heterotrophic – absorb (ready-made) nutrients – secrete enzymes
Cell walls consist of chitin, not cellulose
Also
Non-vascular, mostly as multi-cellular hyphae (except yeast)
Spores (nature, number, presentation) & morphology = past taxonomy
Main groups are the Moulds, Mushrooms and Yeast

Question 2

prokaryotes vs eukaryotes

Answer 2

(pro) ‘before’ + karyon ‘nut, kernel’

DNA loosely gathered in a nucleoid
No organelles
Cell wall = peptidoglycan

(eu) ‘well, good’ + karyon ‘nut, kernel’
DNA with histones in chromosomes in a membrane-bound nucleus
Endoplasmic reticulum, Golgi apparatus, Mitochondria.
Cell wall = polysaccharides (polymers of esp. chitin, mannan, glucan

Question 3

hyphea

Answer 3

Hypha (pl. hyphae) – filaments of cells, septate or aseptate (coenocytic)

Question 4

myecelium

Answer 4

Mycelium (pl. mycelia) – mass of hyphae

Question 5

condiphore

Answer 5

Conidiophore – on aerial hyphae, bearing conidia (asexual spores)

Question 6

sporangiophore

Answer 6

Sporangiophore – stalk with a sporangium
holding spores
(e.g., in mould)

Question 7

spore types

Answer 7

Spore – reproductive structure, haploid/diploid, resistant,
often pigmented
Spore types:
* Chlamydospore – asexual, resting spore, a ‘survival’ structure formed via thickening of a hyphal compartment
* Conidiospores – asexual, at hyphal tip (conidiophore)
* Zygospores – diploid, arising in a zygosporangium
upon fusion of hyphae, germinate to a sporangium
(bearing haploid spores)
* Ascospore – via sexual reproduction, in an ascus (‘sac’)
* Basidiospore – via sexual reproduction, on a basidium

Question 8

asexual life cycle

Answer 8

1. mycelium
2. spores
3. germination
   all are haploid (n)

Question 9

sexual life cycle

Answer 9

1. mycelium
2. plasmogamy where fusion of cytoplasm
3. heterokaryotic stage where unfused nuclei from different parents
4. karyogamy back to fusion of nuclei and zygote stage of diploid (2n)
5. enter meiosis and become spores
6. to germination

Question 10

zygomycota

Answer 10

Hyphae coenocytic, but septate in reproductive hyphae

Question 11

basidiomycota

Answer 11

septate hyphae
club fungi- looks like club
4 basidiospores on a basidium
fruiting body offers increased surface area (gills) and elevation to aid spore dispersal

Question 12

ascomycota

Answer 12

sac fungi, spores in an ascus
8, usually yeast have 4

Question 13

yeast

Answer 13

Not a distinct taxonomic group but are either Ascomycota or Basidiomycota

Most familiar/useful yeast is Saccharomyces cerevisiae
(bakers, brewing, wine yeast)

Yeast are defined as fungi that:

Are predominantly single-celled

Grow asexually via budding or fission

Reproduce sexually either via asco- or basidio-spores

Form pseudo-hyphae
(i.e., cell chains)

Question 14

environmental roles of fungi

Answer 14

decomposers- break down dead material
symbionts- mutual relationship with other species
parasites- feed off living organisms

Question 15

decomposers

Answer 15

• hyphae penetrate larger items
• enzymes excreted to break down lignin
• nutrients absorbed from decaying material

Question 16

symbionts

Answer 16

Mycorrhiza: symbiotic association between fungus and roots of a vascular plant
fungus benefits- access to carbo
plant benefits- access to nutrients

Ectomycorrhiza – extracellular (2% of all plant species; birch, oak, pine, willow, roses, orchids)

Endomycorrhiza – intracellular (70% of all plant species; many crop species)

Question 17

ectomycorrhiza

Answer 17

Fungus relies on carbohydrates ‘leaking’ from plant root cells

Question 18

endomycorrhiza

Answer 18

Fungus has specialised structure: haustorium, which penetrates the plant root cell wall

Question 19

lichens

Answer 19

symbiosis between fungi and green algae or cyanobacteria

Question 20

parasites

Answer 20

host body used to get nutrients
cannot survive without the host

rust fungus- plants
white nose syndrome- bats
chytridiomycosis- amphibians