Learning objectives before Exam 2, on March 9, 2007

Learning objectives:
2-1. What is the Latin name (genus and species) for a human being? (p.705) How is it written?
2-2. An ideal classification system for a group of organisms tells what about the history of that group?
2-3. What were some of the steps of “chemical evolution” in the early earth?
2-4. Name the three domains on the universal tree of life. What are the major cellular and genetic features of each? Which two are thought to have diverged more recently from each other?
2-5. How did changes in the earth's atmospheric O2 relate to the history of organisms on earth?
2-6. What major changes occurred during evolution of eukaryotic cells from prokaryotic ancestors?
2-7. How did multiple endosymbiotic events contribute to diversity of major group of Protists?
2-8. Which of these groups (plants, red algae, fungi, amoebas) is the sister taxon to Animals?
OMIT 2-9. What is "horizontal gene transfer" among the three domains? OMIT
2-10. Explain the characteristic "alternation of generations" in life cycles of plants and many protists.
2-11. In what way is the mode of nutrition of animals and fungi similar? How is it different?
2-12. How are the cells (hyphae) and cell walls of Fungi distinctive? What is the “dikaryon” state?
2-13. From which group of Protists are Animals thought to have arisen?
2-14. What is a phylogenetic tree, and how is it constructed? What are “shared, derived” characters?
2-15. A cladogram is a branching tree showing shared characteristics. Be able to construct a simple cladogram from a table of characteristics.
2-16. Be able to recognize a "monophyletic group" (also known as a “clade”) on a cladogram.
2-17. Do you understand the “misconceptions about humans” on the back of the Phylogeny handout?
2-18. What is the advantage of designating an "outgroup" to construct a cladogram? What does it mean when there are more than two lineages at a particular node on a cladogram?
2-19. Explain the differences between shared ancestry (homology, same structure) and convergent evolution (analogy, same function). Give examples of both.
2-20. Explain this follow-up to 2-19: (a) Divergent evolution may make homologous traits appear dissimilar. (b) Convergent evolution may make traits of different origin look similar
2-21. What modern group of the kingdom Protista is closest to the ancestors of the Plant kingdom?
2-22. Name several major challenges overcome by ancestral plants as they successfully colonizedland. What adaptations (plant traits) helped them be successful?
2-23. What are the gametophyte and sporophyte generations? Explain “alternation of generations”.
2-24. Tell a characteristic feature (e.g., a new trait in the group) of each of the following divisions of the Plant Kingdom: moss, ferns, gymnosperms, angiosperms. What is the outgroup for Plants?
2-25. The three main vegetative (non-reproductive) organs of plants are leaves, stems, and roots. Tell the main general functions of each of these, and be able to pick out these structures in different plants (including vegetable foods).
2-26. Give some examples of highly modified stems, roots & leaves, and tell what specialized functions they serve that allow that particular type of plant to be adapted for a certain habitat or way of life. (Review: be able to explain how such adaptations could have evolved by natural selection.)
2-27. Review the general features of plant cells (fig. 6.9, p. 100) and the functions of the following: chloroplasts, mitochondria, central vacuole, cell wall. What are plasmodesmata? (fig 6.28)
2-28. Tell two ways in which the dermal cells of a root tip (fig 35.12) change (differentiate and mature) after they are produced by mitosis in the zone of cell division.
2-29. What is meristem? Tell where apical meristem & lateral meristem (cambium) are found in trees.
2-30. Explain how the presence of a proton gradient across the membrane can be used by the root hair membrane to take up (a) positive soil ions such as K+; (b) negative soil ions such as NO3-; (c) water. What specific membrane proteins, besides proton pump, are necessary for (a) and (b)?
2-31. If water potential in Part X of a plant is measured as y = - 0.1 and measured as y = - 0.2 at Part Y, which way will water tend to move, from X to Y or from Y to X?
2-32. Distinguish between the apoplast pathway and the symplast pathway. Which is more selective to enter? How does the Casparian strip on endodermal cells serve as a barrier to apoplast flow?
2-33. Why (and in which direction) do plants need to transport water & minerals and sugar solutions?
2-34. In what ways are xylem and phloem cells each specialized for transport?
2-35. Explain step-by-step the upward movement of water in xylem from soil into leaves, defining adhesion, cohesion, root pressure, transpiration. Which one is the most important force?
2-36. Explain the process by which stomata open and close when guard cells swell and shrink. How is the transport of K+ ions involved? Why do stomata generally open in daylight?
2-37. Two specific co-transport systems (each with a symport for protons plus another substance) are described in this chapter. What is transported in each, and where in the plant is each located?
2-38. Sugar solutions move by translocation in phloem from "source" to "sink". Name two plant parts that sometimes act as sources of sugars and two that can act as sugar sinks (use up sugars).
2-39. Explain the pressure-flow hypothesis of sugar transport. What steps require ATP?
2-40. The major nutrients needed by plants (plus light energy) are: CO2, H2O, O2, and minerals such as potassium, phosphate and nitrate ions. For each of those nutrients, tell the plant part into which it enters the plant and give an example of how it is used in plant cells.
2-41. Name some adaptations by which desert plants can minimize water loss.
2-42. Mistletoe is green and photosynthetic. In what way does it behave like a parasite?
2-43. Mycorrhizae are symbiotic associations of fungi and plant roots. How does each partner benefit from the symbiosis?
2-44. What evolutionary changes in reproduction and dispersal stages helped plants to become independent of water and successful living on land? How did insects facilitate angiosperm diversity?
2-45. Tell how monocots and dicots differ (a) in flower structure and (b) in seed structure.
2-46. Identify each of the following: flower, petal, sepal, carpel, anther
2-47. Write out a general, simple life cycle (diploid-meiosis-haploid-fertilization-diploid). In what structures/organs does meiosis occur in humans? Where does meiosis occur in a flowering plant?
2-48 How does cytokinesis and survival of 4 microspores (in anther) differ from that of megaspores?
2-49. What is the male gametophyte in a flower? What is the difference between the male gametophyte and a sperm nucleus? What is the difference between pollination and fertilization?
2-50. Which nuclei (of the male and female gametophytes) are involved in double fertilization, and what are the two products of double fertilization?
2-51. Tell whether each of the following is haploid, diploid, or triploid: petal, pollen, embryo sac,
endosperm, ovary
2-52. When a pollen grain nucleus fertilizes an egg nucleus from the same individual plant ( = self-pollination), is that the same as asexual reproduction?
2-53. What are some examples of flower adaptations to attract specific pollinators?
2-54 The fruit develops from what flower part? What is the function of fruit? To nourish the embryo?
2-55. What is an evolutionary advantage for plants having structures promoting seed dispersal? Give examples of seed dispersal adaptations for wind dispersal and animal dispersal.
2-56. Describe the process of seed germination, including imbibition of water and the hormone signal that triggers enzymes that mobilize nutrients from storage in the endosperm. (see fig. 39.11)
2-57. Give two examples of asexual (vegetative) reproduction in plants. Compare the evolutionary advantages of sexual and asexual reproduction.
2-58. Review the main components of signal transduction (fig. 39.3); be able to apply to plant cells.
2-59. Define “tropism”, and give some specific examples of tropisms.
2-60. Explain what we learned from the experiments of Darwin, Boysen-Jensen, and Went on
phototropism. Why was each experimental step needed?
2-61. Design an experiment (identifying independent, dependent and control variables) to test one
aspect of phototropism.
2-62. Explain the “acid-growth” hypothesis for the bending of a shoot towards the light. List the steps
by which cells elongate in response to auxin.
2-63. What is abscissic acid’s effect on guard cells? Relate this to ABA’s role as a “stress hormone”.
2-64. Explain the process of seed germination (beginning with imbibition, up to mobilization of sugars for seedling growth). Contrast the roles of gibberellins and abscissic acid in seed development.
2-65. A mutant plant can produce auxin but not respond to it. What protein is abnormal in that plant?