Readings and Study Questions for Week 9 (Mar. 5)

Essential Reading

Brooker Biology excerpted text Chapter 31

1. What is unique about the body form of fungi compared to the two other lineages of multicellular organisms, plants and animals? How does this difference affect our understanding of body size in fungi?
2. What is osmotrophy? How is this related to ability of fungi and lichen to dissolve rocks and penetrate other hard to get to places?
3. Fungi are a member of the super group Opistokonta. What are the other members of this super group? What is the sister group to the Fungi? What characteristic unites these two groups?
4. Why are Ascomycota and Basidiomycota grouped into the larger category called Dikarya?
5. What is the role of mycorrhizae compared to that of nitrogen fixing prokaryotes?
6. Fungi are heterotrophs, but a large number of species has evolved mutualisms with photoautotrophic organisms. These mutualistic associations (lichens) are classified as if they were species. Discuss this association in light of the endosymbiotic theory of the origin of eukaryotes.
7. It is said that without fungi life on earth (as we know it) would come to a fairly quick end. What is the main contribution of saprotrophic fungi (fungi that break down dead tissue)?
8. What two phyla of fungi contain the greatest number of species and greatest diversity of habits?
9. Early-diverging fungi groups have flagellated zoospores, whereas late-diverging groups have unfagellated zoosprores. Why has this shift occurred?
10. Under what environmental conditions do you expect fungi to reproduce asexually and under what environmental conditions do you expect them to reproduce sexually? Why?
11. What are the oldest confirmed fossil fungi and how old are they? What does this tell you about the origin other major groups of fungi?
12. Fungi have evolved in a marine habitat, and it is thought that diversification occurred long before reliable fossil evidence is available. Why must there have been diversification before fossils appear in the Cambrian and Ordovician?
13. What is meant by alternation of generations in the fungal life cycle? What is the heterokaryotic stage of the life cycle and its relationship to the processes of karyogamy and plasmogamy?
14. Many plants have a mutualistic relationship with endophytic fungi. Give an example of how such an endophytic fungus might benefit a plant. How you would experimentally test this effect?
15. Give an example of a mutualistic relationship and a parasitic relationship involving fungi and ants.
16. Give some specific examples of how humans have use fungi for their own benefit.