Fungi

Question 1

What are cellular slime moulds?

Answer 1

almost microscopic aggregations of amoebae differentiate into spore bearing fruiting structures

Question 2

What signal induces directional cellular growth in amoeba?

Answer 2

cAMP

Question 3

What are plasmodial slime moulds?

Answer 3

large single cells contain many nuclei

Question 4

What is the cell cycle of a budding yeast?

Answer 4

1. Spindle pole body (SPB) duplication and initiation of DNA synthesis
2. Bud emergence and SPB seperation
3. nuclear migration
4. nuclear division
5. cytokinesis and cell separation

Question 5

What is mycelium?

Answer 5

a fungal network composed of multiple interconnected hyphae

Question 6

What is the role of a woronin body in a hypha?

Answer 6

seals up hole to stop leakage of fluid from cell if tip bursts

Question 7

Where are fungal spores produced?

Answer 7

in the gills of fungal fruit

Question 8

What are slime moulds?

Answer 8

Aggregations of amoebae that differentiate into fruiting structures

Aggregate to form “slugs”

cAMP used as signal to make amoebae move together (cAMP induces pseudopods in amoebae)

Question 9

Plasmodial slime mould aggregates?

Answer 9

Form one giant multinucleate plasmodium when they aggregate (thousands/millions of nuclei)

Exits as single wall-less cell
Exhibit pulsed protoplasmic streaming at approx 30swc intervals to move

Question 10

What are germ tubes?

Answer 10

specialised hyphae which emerge during spore germination and are involved in colony establishment

Question 11

What are septa?

Answer 11

form walls and act as hyphae dividers
have pores that allow passage of organelles and cytoplasms between adjacent compartments

septum formation is like cell cleavage during mitotic division

Question 12

What is the spitzenkörper?

Answer 12

also known as apical body or apical vesicle cluster
a muti component organelle assemblage predominated by vesicles

plays a vital role in regulating hyphal tip growth

hyphal branching is preceded by the formation of a new spitzenkörper at the site of new branch formation

Question 13

Where is the majority of mitochondrial activity found in fungi?

Answer 13

at hyphae tips

Question 14

What is hyphal fusion?

Answer 14

hyphal branches grow towards each other in older parts of the fungal colony

Question 15

What are nuclear comets?

Answer 15

groups of >100 nuclei that move rapidly through colony networks

Question 16

What are nematrophs?

Answer 16

parasites of nemarode worms
nematodes are trapped by specialised hyphae and adhesive knobs + hyphae

Question 17

What are mycoses and what types are there?

Answer 17

diseases cause by fungi
mainly opportunistic

1. dermatophytes
2. commensals
3. opportunistic pathogens of the lungs

4, opportunistic pathogens of wounds

5. naturally live in lungs

Question 18

What are dermatophytes?

Answer 18

grow on dead, keratinised tissues of the skin
are keratinophilic via keratinases
break down disulphide bridges

Question 19

What are the main antifungal compounds used to treat human mycoces?

Answer 19

1. azoles - inhibit ergosterol synthesis, a main component of fungal plasma membrane
2. polyene antibiotics - associates w ergosterol in plasma membrane to form pores disrupting ion homeostatis
3. echinocandins - inhibit synthesis of beta(1,3)-glucan synthesis, a major component of fungal cell walls. action resembles that of penicillin
4. flucytosine - inhibits DNA and protein synthesis

Question 20

What are some novel uses of fungi?

Answer 20

1. fungal textiles
2. medical products
3. food products