Oomycota 1
What types of evidence show that the Oomycota are stromenopiles and not fungi?
What is the difference between primary and secondary zoospores in terms of morphology, location in the life cycle, and distribution throughout the Oomycota.
As applied to zoospores define the following terms and explain the differences between them monomorphic, dimorphic, aplanetic, monoplanetic, diplanetic, polypanetic.
Define the following types of thalli (Holocarpic, eucarpic, monocentric, polycentric) and give an example of a taxon that has each (you can expand to the Chytrids and Hyphochytrids for your answer)
Select a member of the Saprolegniales and diagram its lifecycle indicating the main structures (thalli, sporangia, gametangia, etc,) nuclear condition (haploid or diploid) of various structures, and the sites of karyogamy and meiosis.
What are the various ways that members of the Saprolegniales release zoospores from their sporangia. For each indicate a genus where this method of release can be found.
What is the sequence of hormonal interactions that causes differentiation of gametangia and mating in heterothallic Achyla species.
What are some of the ecological roles that members of the Saprolegniales fill?
Oomycetes 2What features separate the Peronosporomycetidae from the Saprolegniomycetidae?
Diagram the lifecycle of Pythium or Phytophthora and discuss the important structures and events in it.
Compare the ecological roles of Pythium and Phytophthora; when possible give examples of species that fill these roles.
Define and/or diagram the following terms: indeterminate sporangiophore, amphigynous anteridium, direct germination, damping off; give an example of a species where you could find each.
What features of the Hyphochytridiomycota separate them from the Oomycota?
Oomycetes 3Diagram a lifecycle from a member of the Peronosporaceae, discuss the major features of it, and compare it to that of Phytophthora infestans.
How do weather conditions interact with the spread of downy mildews? What are some historically important epidemics?
Diagram and discuss the infection process of a typical downy mildew.
What features of Albugo are similar to other Oomycota and which are unique to the family?
What distinguishes Lagenidium from Pythium?
What features of the Rhipidiales or Leptomitales make members of each of these orders unique? Where might you look for members of these orders in nature.
Looking at the evolution of the Oomycota as a whole, what features or behaviors seem to have been derived repeatedly. How does this correlate with the niches they exploit.
Zygomycetes 1Diagram the development of a typical zygospore, label the structures involved, and indicate where you would expect to find karyogamy and meiosis.
What is the difference between opposed and apposed suspensors and how do these two types correlated with where the zygospores are produced.
What hormonal interactions are involved with gametangial maturation and fusion in the Mucorales?
What is an azygospore? and how is it thought to correlate with homo or heterothallism?
Discuss how spore dispersal is accomplished through space and time by members of the Mucorales. How are these methods related to the habitats that they exploit?
What spore states other than sporangiospores and zygospores exist in the Mucorales?
In what groups of Zygomycetes would you expect to find heterothallism?
Draw a sporangium and label the parts.
The families in the Mucorales are defined in large part by type of sporangia and sporaniola that are produced. Given what you know about the evolutionary pattern of the families, what does this say about these spore characters.
Zygomycetes 2What are sporocladia and pseudophialides and where could you find them.
Why are members of the Dimargaritales often difficult to maintain in culture.
What types of spore dispersal are used in the Entomophthorales?
What is a haptor and where might you find one?
Where would you expect to find members of the following orders and what would are they likely to be doing in these habitats: Kickxellales, Dimargaritales, Entomophthorales, Zoopagales.
What are some morphological structures and behaviors that are employed by members of the Dimargaritales and the Zoopagales to parasitize other fungi.
What is a trichospore, what does it look like, and where would you expect to find one?
Are the Trichomycetes a natural group (monophyletic)? What is the basis for the Trichomycetes being placed in their own class distinct from other Zygomycetes? Given what we now know is this justified?
Zygomycetes 3What is a sporocarp? What is an example of a member of the Zygomycota that has one, and how does it facilitate spore dispersal?
Diagram the features in a typical arbuscular mycorrhizal symbiosis and describe what each one does (to the extent we know), and discuss the what plant and fungal partners receive in this interaction.
The spores of the Glomales are variously called azygospores or chlamydospores. What type of morphological variation exists in glomalean spores and why all the confusion over what they are?
Glomalean fungi are always biotrophs, but are they always mutualists? Provide examples with your answer.
How does Geosiphon make its living and why is it in the Glomales (or Glomeromycota)
Overview questions:What are some common trends throughout the Zygomycota.
Looking at what we currently call the Zygomycota what actually unites them? What is the problem with this character or characters?
Repeat the above question but substitute the Chytridiomycota.
What are the similarities between the resting sporangium of the Chytridiomycota and the Zygosporanium of the Zygomycota. How can one distinguish between them?
Pick two pairs of taxa in which the members look or behave in very similar ways, yet do not share a unique common ancestor.
The number of species within various orders vary dramatically pick a small order and speculate on why it is small.