fungi xoxo

Question 1

what are fungi good for

Answer 1

recycling
providing us with food
medicines
enzymes

Question 2

biggest threat to global food security

Answer 2

fungal infection

Question 3

where are pathogens moving

Answer 3

polewards

increasing numbers at higher latitudes

Question 4

5 crop pathogens

Answer 4

wheat stem rust
rice blast
potato late blight
corn smut
soybean rust

Question 5

how many microbes

Answer 5

between 100 billion and 1 trillion

Question 6

how is microbial diversity created

Answer 6

microbes adapting to their environment

Question 7

methods for classifying microbial diversity

Answer 7

1. Morphological Diversity
   - (features,structures, key advance - microscopy)
2. Metabolic Diversity
   - (biochemical key advance – enzymology)
3. Ecological Diversity
   - e.g. extremophiles
4. Genetic Diversity
   - (Gene Sequences
   key advances - molecular biology, DNA sequencing, genome comparisons)

Question 8

coccus shape

Answer 8

round/spherical

Question 9

morphological diversity

Answer 9

sufficient to distinguish between pro/eukaryotic
able to see obvious prokary differences

can’t distinguish microbe types that appear similar

metabolic differences can help

Question 10

metabolic diversity

Answer 10

biochemical differences

differences in carbon and energy sources

Question 11

ecological diversity

Answer 11

different environmental conditions:

temp - hyperthermophile, psychrophile
salinity - halophile (high salt conc.)
pressure - barophile
pH - acidophile, alkilophile

Question 12

5 kingdoms

Answer 12

monera
protista
animalia
fungi
plantae

Question 13

genetic diversity

Answer 13

DNA sequencing allows comparison of genes/genome

phylogenetic trees created using DNA sequencing

16s ribosomal subunit sufficient to see evolutionary changes - all organisms contain ribosomes

Question 14

ribosomal RNA sequencing

Answer 14

1. Pure culture or environmental sample cells are lysed and DNA isolated
2. Gene-encoding ribosomal RNA is isolated and amplified by PCR 3. Amplified rRNA gene is sequenced
3. Obtained sequences aligned by computer - pairwise comparisons - tree
4. Tree depicts difference in rRNA sequence between organisms

Question 15

largest group of bacteria

Answer 15

proteobacteria

Question 16

2 major sub-groups of archaea

Answer 16

primary hyperthermophiles

methanogens and halophiles and acidophiles

Question 17

what is common of ‘early branching’ on a eukaryotic phylogeny tree

Answer 17

lack of mitochondria and eukaryotic specific organelles

Question 18

taxonomic classification - 8 subgroups

Answer 18

domain
kingdom
phylum
class
order
family
genus 
species

Question 19

when did fungi colonise the land

Answer 19

during the cambrian period, 500 million years ago

Question 20

what can fungi be used for

Answer 20

drugs
organic acids
biofuels

Question 21

how do fungi threaten humans

Answer 21

rot our house
make our feet smell
destroy our crops

Question 22

how do fungi threaten humans

Answer 22

rot our house
make our feet smell
destroy our crops

Question 23

clade

Answer 23

monophyletic group -composed of a single ancestor

Question 24

hyphae

Answer 24

branching filaments that make up the myecelium of a fungus

myecelium = vegetative part of a fungus

Question 25

fungi features

Answer 25

dimorphic
heterotrophic
absorb soluble nutrients through their wall and secrete enzymes through their wall

Question 26

fungal cell wall

Answer 26

chitin and glucans

Question 27

fungal cell membrane

Answer 27

ergosterol

Question 28

microsporidia

Answer 28

closely related to fungi
unicellular spores
infect animals and insects - e.g. cause diarrhoea in humans

Question 29

fungal phyla

Answer 29

Chytridiomycota
• (Blastocladiomycota) 
• Zygomycota
• Glomeromycota
• Ascomycota
• Basidiomycota

Question 30

Chytridiomycota

Answer 30

microscopic mould with chitin wall

contains unreleased swimming spores (zoospores)

Found in aquatic environments and soils

Some soil chytrids are parasitic on vascular plants

Question 31

zygomycota

Answer 31

Some are saprotrophic – soil and dung

• Found on mouldy fruit and bread
• Parasitic on insects, rotifers and even amoebae
• Mucor spp cause zygomycosis on humans, frogs, cattle and pigs
• two hyphae fuse to form zygote
• multinucleate mycelium

infections affect immunocompromised patients

live on decaying plant or animal material or in soil

Question 32

glomeromycota

Answer 32

obligate symbionts formation of arbuscules in PLANT ROOTS
large, multi-nucleate; spores with layered walls

non‐septate hyphae

Question 33

ascomyctoa

Answer 33

largest group in kingdom fungi
Filamentous fungi and some yeasts

Most lichenised fungi
• Septate hyphae
• Carry their sexual spores in a sac-like structure called the ascus

some pathogens to humans and plants - e.g. candida albicans
some edible or used to make food

Question 34

basidiomycota

Answer 34

plant pathogens - wood decay
mushrooms and jelly moulds
diverse group
basidiospores - sexual reproduction
clamp connections - asexual

Question 35

4 types of lichen

Answer 35

Crustose
- crust-like and adhere tightly to the surface upon which they grow.

Foliose
- are leaf-like , composed of flat sheets of loosely bound tissue

Squamulose
-composed of scale-like parts

Fruticose - are composed of free-standing
branching tubes

Question 36

lichens

Answer 36

• Lichens are mutualistic (symbiotic) associations between a fungus (the mycobiont) and a photosynthetic algal or cyanobacterial partner (the phycobiont).
• About 30,000 species known

• Lichen symbioses nearly always involve
Ascomycota, very rarely Basidiomycota.

• Lichens are important as animal food, in Arctic, lichens form as much as 95% of diet of reindeer

• Also sources of usnic acid - antibiotics - and antivirals


Question 37

structure of a lichen

Answer 37

upper cortex of fungal hyphae

middle layer of photobiont cells

medulla of fungal hyphae

Question 38

proof lichens are resilient

Answer 38

2005 - taken to space

exposure to extreme temp. and radiation - showed no damage

Question 39

1914

Answer 39

strain selection / Koji process

Question 40

1929

Answer 40

fleming and antibiotics

Question 41

1942

Answer 41

Tatum & Beadle “one-gene, one-enzyme hypothesis” in Neurospora crassa

Question 42

1953

Answer 42

Roper described parasexual analysis in Aspergillus nidulans (….Pontecorvo)

Question 43

1955

Answer 43

Backus & Stauffer initiated mutagenesis in

Penicillium chrysogenum

Question 44

1967

Answer 44

Pirt & Righelato introduced continuous culture

Question 45

1984

Answer 45

Ball, parasexual breeding

Question 46

1987

Answer 46

recombinant DNA/transformation

Question 47

fungi in genetic analysis

Answer 47

 One gene‐one enzyme hypothesis
(Neurospora crassa) - Beadle and Tatum

 Dissection of yeast life-cycle
(Saccharomyces cerevisiae Schizosaccaromyces pombe ) - Hartwell and Nurse

• B-lactam antibiotics
(Penicillium spp) Nobel prizes for Fleming, Florey and Chain for penicillin and Dorothy Hodgkin for crystal structure

Question 48

why are fungi good for biochemical studies

Answer 48

simple nutrient requirements
ease of growth
• Short life-cycles
• Most are haploid
• Many have a sexual stage
• Produce asexual spores that can be used or stored in bulk

Question 49

heterothallic fungi

Answer 49

require two compatible partners to produce sexual spores, from homothallic ones, which are capable of sexual reproduction from a single organism.

Question 50

homothallic

Answer 50

the possession, within a single organism, of the resources to reproduce sexually i. e having male and female reproductive structures on the same thallus.

Question 51

citric acid production

Answer 51

fermentation by Aspergillus niger