Eukaryotes Flashcards
What is a hypha? A mycelium? Septa?
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
Vegetative hypha
The portion of a hypha that obtains nutrients is called the vegetative hypha
Reproductive or aerial hypha
The portion of a hypha that is related to reproduction
Differentiate b/w asexual spores and sexual spores. Which one occurs more frequent?
- Asexual spores: formed by the hyphae of ONE organism
- Sexual spores: resulted from the fusion of nuclei from TWO opposite mating strains of the same species of fungus
- Asexual spores are produced more frequently
List the 2 types of conidiospore
- 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
List the 3 types of asexual spores
- Conidiospore
- Chlamydospore
- Sporangiospore
List the 3 phases of sexual spore production
- Plasmogamy
- - A haploid nucleus of a donor cell (+) penetrates the cytoplasm of a recipient cell (-) - Karyogamy
- - The (+) and (-) nuclei fuse to form a diploid zygote nucleus - Meiosis
- - The diploid nucleus gives rise to haploid nuclei (sexual spores), some of which may be genetic recombinants
Explain the life cycle of a zygomycete (including asexual and sexual reproduction)
- Aerial hypha produces a sporangium
- Sporangium bursts to release spores
- Spore germinates to produce hyphae
- Vegetative mycelium grows
- Gamete forms at tip of hypha
- Plasmogamy
- Zygospore forms
- Karyogamy and meiosis
- Zygote produces a sporangium
- Spores are released from sporangium
Explain the life cycle of a ascomycete (including asexual and sexual reproduction)
- Hypha produces condidiophore
- Conidia are released from conidiophore
- Condidium germinates to produce hyphae
- Vegetative mycelium grows
- Plasmogamy
- Karyogamy
- Meiosis then mitosis
- Ascus opens to release ascospores
- Ascospore germinates to produce hyphae
Explain the life cycle of a basidiomycete (including asexual and sexual reproduction)
- Hyphal fragment breaks off vegetative mycelium
- Fragment grows to produce new mycelium
- Vegetative mycelium grows
- Pasmogamy
- Fruiting structure (mushroom) develops
- Basidiospores are formed by meiosis
- Basidiospores mature
- Basidiospores are discharged
- Basidiospore germinates to produce hyphae
How many basidiospores per basidium?
4