Eukaryotes

Question 1

What is a hypha? A mycelium? Septa?

Answer 1

a. Hypha: Filaments that join vegetative cells together
b. Mycelium: when the environmental conditions are suitable, the hyphae grow to form a filamentous mass called a mycelium
c. Septa: cross-walls in a hypha which divide them into distinct, uniculeate cell-like units

Question 2

Vegetative hypha

Answer 2

The portion of a hypha that obtains nutrients is called the vegetative hypha

Question 3

Reproductive or aerial hypha

Answer 3

The portion of a hypha that is related to reproduction

Question 4

Differentiate b/w asexual spores and sexual spores. Which one occurs more frequent?

Answer 4

1. Asexual spores: formed by the hyphae of ONE organism
2. Sexual spores: resulted from the fusion of nuclei from TWO opposite mating strains of the same species of fungus
3. Asexual spores are produced more frequently

Question 5

List the 2 types of conidiospore

Answer 5

1. Conidiospore or conidium: unicellular or multicellular spore that is not enclosed in a sac
   a. Arthrospore: formed by the fragmentation of a septate hypha into single, slightly thickened cell
   b. Blastoconidia: consists of buds coming off the parent cell

Question 6

List the 3 types of asexual spores

Answer 6

1. Conidiospore
2. Chlamydospore
3. Sporangiospore

Question 7

List the 3 phases of sexual spore production

Answer 7

1. Plasmogamy
   - - A haploid nucleus of a donor cell (+) penetrates the cytoplasm of a recipient cell (-)
2. Karyogamy
   - - The (+) and (-) nuclei fuse to form a diploid zygote nucleus
3. Meiosis
   - - The diploid nucleus gives rise to haploid nuclei (sexual spores), some of which may be genetic recombinants

Question 8

Explain the life cycle of a zygomycete (including asexual and sexual reproduction)

Answer 8

1. Aerial hypha produces a sporangium
2. Sporangium bursts to release spores
3. Spore germinates to produce hyphae
4. Vegetative mycelium grows
5. Gamete forms at tip of hypha
6. Plasmogamy
7. Zygospore forms
8. Karyogamy and meiosis
9. Zygote produces a sporangium
10. Spores are released from sporangium

Question 9

Explain the life cycle of a ascomycete (including asexual and sexual reproduction)

Answer 9

1. Hypha produces condidiophore
2. Conidia are released from conidiophore
3. Condidium germinates to produce hyphae
4. Vegetative mycelium grows
5. Plasmogamy
6. Karyogamy
7. Meiosis then mitosis
8. Ascus opens to release ascospores
9. Ascospore germinates to produce hyphae

Question 10

Explain the life cycle of a basidiomycete (including asexual and sexual reproduction)

Answer 10

1. Hyphal fragment breaks off vegetative mycelium
2. Fragment grows to produce new mycelium
3. Vegetative mycelium grows
4. Pasmogamy
5. Fruiting structure (mushroom) develops
6. Basidiospores are formed by meiosis
7. Basidiospores mature
8. Basidiospores are discharged
9. Basidiospore germinates to produce hyphae

Question 11

How many basidiospores per basidium?

Answer 11

4