Quiz 8 Flashcards
What is similar about all eukaryotic microbes in terms of their cellular structure?
All have a nucleus and other membrane-bound organelles, similar looking chromosomes, size, etc.
What is meant by the statement that fungi are absorptive heterotrophs? What are saprophytes vs parasites? What is decomposition?
they acquire nutrients from dead organisms (saprophytes) or living things (parasites)
Decomposition involves using enzymes to break down organic matter
What do fungi require for growth and what do they do for plants?
They require organic compounds in order to grow
Many provide plant roots with nutrients from the soil
What is different about fungi cell wall (when compared to that of a plant)?
Cell wall made of chitin, sugars, and glycoproteins
Know the difference between the yeast vs mold form
Yeasts are single-celled, non-filamentous, and usually spherical/oval
Molds grow as multicellular filaments of connected cells
How do yeasts divide? What is the difference mechanistically between budding and fission?
Yeasts divide by either budding or fission
Budding: parent cell forms a small bud on one side, a cell wall is built between them, and the bud breaks away
Fission: cell elongates and splits in the middle
What are hyphae and mycelia? What about aerial hyphae?
Hyphae are multicellular filaments of connected cells, and mycelia is the name for a group of hyphae
Aerial hyphae form off of surfaces and hold reproductive spores
How and why do hyphae grow (what are they trying to find?)?
Hyphae grow by elongating their ends, often to reach nutrients
What is the difference between septate and coenocytic hyphae?
Septate hypha: cells are separated by septa
Coenocytic hyphae: cells are continuous, no separations
What is a dimorphic fungus and what would trigger the switch in growth forms?
Dimorphic fungi can switch between growing as a yeast or a mold
- yeast when nutrient levels are high
- mold when they are deprived of nutrients (produce hyphae and elongate in order to find nutrients)
Know the generic differences between asexual and sexual reproduction of fungi
Asexual reproduction of fungi: one parent produces genetically identical offspring
Sexual reproduction of fungi: Two haploid cells fuse to form one diploid cell, which then undergoes meiosis in order to produce new haploid cells
- offspring is a genetic mix of two parents
How do yeasts reproduce asexually?
Unicellular yeasts reproduce asexually through budding or fission
- offspring is genetically identical to parent
How do molds reproduce asexually?
Multicellular molds produce asexual spores that get released into the environment, wherever they land they start producing new hyphae
Asexual spores of molds
- What is a conidiospore and conidiosphore (what characterizes them)?**
Conidiospores are unicellular or multicellular spores that are not enclosed in a sac
Asexual spores of molds
- What is the difference between a thallic and blastic conidiospores?
Thallic: form from preexisting hyphae
Blastic: form from new growth
Asexual spores of molds
- What is the difference between the two types of thallic spores - arthroconidia and chlamydocondia?
Arthroconidia: hyphae further septate and fragment apart at the ends to form new spores
Chlamydocondia: spores form from cells inside a hypha that thicken and release
Asexual spores of molds
- What are sporangiospores, sporangium, and sporangiophores?
Sporangiospores are a type of asexual mold spore
- the spore is enclosed in a sac called a sporangium
- they are produced at the end of a hypha called a sporangiophore
Sexual reproduction of fungi
- What is the general process by which fungi reproduce sexually? What is meant by plasmogamy and karyogamy? How do zygotes create haploid sexual spores?
Hyphae from different mycelia interact
1) two cells fuse –> cell with two nuclei (plasmogamy)
2) the two nuclei fuse into one (karyogamy)
3) cell undergoes meiosis to create haploid sexual spores
