FS561: Physiology of Woody Plants

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					FS561: Physiology of Woody Plants

Please keep in mind that the material covered in class varies from year to year, so the content of
some of these questions may not be exactly appropriate for this year.

Answer each of the following true (T) or false (F)
  1._____ All woody plants are vascular plants.
  2._____ The long hydrocarbon chain of fatty acids is generally hydrophobic, so fats are not
likely to be dissolved in the cytosol of a cell
  3._____ If the temperature of air increases while the absolute humidity and total air pressure stay
constant, the vapor pressure deficit will increase
  4._____ During active photosynthesis, photosynthetic electron transport takes place in the
thylakoid membranes of the chloroplast, causing the lumen to have a lower pH than the stroma
  5._____ As temperature increases above the optimum for photosynthesis, the rate of respiration
rises faster than the rate of gross photosynthesis, causing net photosynthesis to be reduced

11. (1) Why doesn’t a light response curve pass through the origin (i.e., where net photosynthesis
and irradiance are both zero)?. (explain very briefly)

15. (1) When a plant is water stressed, how is carbon isotope discrimination () likely to compare
with an identical plant with adequate water in the same light conditions? (choose one)

       increase    decrease    stay the same

19. (1) Why is the rate of net photosynthesis lower for most woody plants in a high O2
environment compared with a low O2 environment?

20. (1) Which of the following is the most appropriate way to describe quantum flux density
       (choose one):
       a. J s-1
       b. W m-2
         c. mol m-2 s-1
         d. J s-1 m-2

25.(1) Suppose you wanted to select genotypes of seedlings that had high water-use efficiency, and
you grew them from seeds in a greenhouse under a controlled environment that was identical for all
plants and measured the 13C of foliage. Which plants would you select (choose one)?

         a. The plants with highest 13C (i.e., “least negative”, or closest to zero)
         b. The plants with the lowest 13C
         c. Neither – you can’t predict water use efficiency from 13C of foliage

26.       (2) Oaks are more likely to grow faster than birch trees in a warm, wet environment, but
      birch trees are more likely to survive in very cold regions. Explain these differences based on
      the calculations you performed in one of your homework assignments on xylem anatomy of
      stems of oaks and birch.

27.      During the summer, the stomata of many plants close in the middle of the day when
      temperature and vapor pressure deficit are high.

      a. (1) Which of the following do you expect would happen to the ci/ca ratio of a leaf after mid-
      day stomatal closure compared with earlier in the day when stomata are open? (choose one)

      increase          decrease                stay the same

      b. (1) Which of the following is likely to happen to ?

      increase          decrease                stay the same

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