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Chapter Two
Hungry Planet: Stories of Plant Diseases

Questions for Discussion

1.  Even though different kinds of eukaryotic organisms can exist in the diploid, haploid, or dikaryotic state, they all go through the same three steps during sexual reproduction: meiosis, plasmogamy, and karyogamy. What happens to the nuclei in each step, and when do the steps occur in people, ascomycetes, basidiomycetes, and oomycetes?

2.  What is the difference between the functions of mitosis and meiosis?

3.  From a practical point of view, oomycetes are often studied with ascomycetes, basidiomycetes, and other true fungi as similar pathogens that produce hyphae and spores. From a biological standpoint, why is it important to try to group organisms more precisely in terms of their evolution from common ancestors?

4.  To what extent does biology determine destiny in the ability of a fungus or funguslike organism to be a plant pathogen? For example, even though all fungal spores require water for germination, why are the oomycetes given the name “water molds”?

5.  Why do most fungi and funguslike organisms produce both sexual and asexual spores? What roles do the spores play in the life cycles of the organisms?