objectives before Exam 2, on March 9, 2007
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
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
2-6. What major changes occurred during evolution of eukaryotic cells from prokaryotic
2-7. How did multiple endosymbiotic events contribute to diversity of major group
2-8. Which of these groups (plants, red algae, fungi, amoebas) is the sister taxon
OMIT 2-9. What is "horizontal gene transfer" among the three domains?
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
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,
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
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
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
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
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
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
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,
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
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?