April 6, 1992

Write your name in the space provided above. Double check to be sure you have left no items blank. Make sure your responses are LEGIBLE; if a response is uncertain, it will be marked WRONG. This exam represents 100 of the 1000 points in the course. After this exam is returned to the class, you will have one week to challenge the grading of the exam. Your request must be submitted in writing and should defend your answer.

MULTIPLE CHOICE Circle the letter corresponding to the ONE BEST completion of the statement or answer to the question to the left of each numbered item below.

1. Plant growth regulators

A. are high molecular weight proteins
B. are transported directly to the responding tissue
C. are nutrients for plant growth
D. do not completely fit the traditional hormone definition
E. all of the above
2. You place a pair of guard cells with osmotic potential of -10 bars into a large volume of a solution with -15 bars osmotic potential. Assume your lab is at standard temperature at sea level. What will be the pressure potential of the cells after they come to equilibrium with the solution?
A. +5 bars
B. 0 bars
C. -5 bars
D. -10 bars
E. -15 bars
F. -25 bars
3. The stoma controlled by the guard cells in #2 above at equilibrium will be
A. opened wider than before equilibrium
B. opened just as wide as before equilibrium
C. open
D. closed
E. burst open as the cell membranes rupture
4. Ammophila (beachgrass), a C-4 plant, has
A. PEPcarboxylase (PEPCo)
B. RuBPcarboxylase (RuBisCo)
C. both enzymes above
D. neither enzyme above
5. The dark reactions of photosynthesis
A. may function at night in some plants
B. function only at night
C. trap the energy of light by attaching another phosphate to ADP
D. trap the energy of light by attaching carbon atoms to pre-existing organic molecules
E. are involved with none of the above
6. When soil moisture and relative humidity are high, the leaves of some plants will exude a droplet of water early in the morning (cool, still air). This phenomenon, called guttation, is due largely to
A. root pressure
B. evaporative pull
C. condensation of water on the leaf
D. leaky open stomata
E. capillarity
7. The growth rings in the xylem of a perennial woody dicot
A. are a result of the cellular response to seasonal fluctuations in environmental conditions
B. are formed as a result of the annual addition of many rows of fibers at the end of each season
C. may simply be counted to accurately determine the exact age of the plant
D. are found only in the trunk or stem
E. have none of the above attributes
8. Antenna pigments
A. detect the wavelengths of light which are most efficient for photosynthesis
B. extend the range of wavelengths which can be used by the reaction center pigments
C. transfer energy from a range of wavelengths to the photosynthetic pigments, increasing photosynthetic capacity
D. are specialized reaction center pigments that transfer energy directly to electron transport system carriers
E. make the antenna more appealing to the JonesŐs next door
9. Cambial meristems of woody plants give rise to
A. endoderm
B. periderm
C. stem branches
D. lateral roots
E. leaves
10. When a pigment absorbs a photon of light
A. an electron is excited to a higher energy shell
B. the photon may be re-emitted at a shorter wavelength
C. an excited electron may be passed to a reduced electron acceptor, thereby oxidizing the acceptor
D. all of the above occur
E. none of the above occur

TRUE-FALSE (1 point each) Darken the circle before each TRUE statement below:

O 11. The light reactions produce a constant ratio of ATP and NADPH + H+.
O 12. All higher plants that fix carbon utilize the Calvin cycle (C-3 dark reactions).
O 13. CAM plants have virtually the same dark reactions as C-4 plants,
      but the CAM separation of CO2 trapping and sugar synthesis reactions is spatial
      while that of C-4 plants is temporal.

SEQUENCES (1 point each blank). Given the following vocabulary, list the sequence of corresponding letters of the cells from outside to inside of a woody dicot root as directed. All blanks provided may not be needed for each numbered sequence. Not all cells may apply to a sequence.

A. corkF. metaxylemK. pith
B. cork cambium initialG. pericyclicM. primary sieve element
C. corticalH. phellodermalN. protoxylem
D. endodermalI. phloem ray cellP. root hair
E. fusiform initial

14. Sequence from the outside of the root through endodermis:

15. Sequence from just inside the endodermis up to, but not including, the outer-most conducting tissue:

16. Sequence from the outer-most conducting tissue to the center of the root:

17. Name the three meristems that give rise to the primary and secondary plant body and list beneath them the organs, tissues, layers, and regions (NOT CELLS!) of the plant produced by each of these meristems. Not all blanks may need to be used, and there may not be enough blanks in a column to be inclusive.





18. Indicate which of the following photosynthetic reactions (if any) correspond DIRECTLY to the processes, structures, substances, etc., by darkening the appropriate circles in the chart below.
"Dark" Reactions
Kreb's Cycle intermediatesOOOO
electron transport systemOOOO
production of NADPH+ H+OOOO
oxygen evolutionOOOO
respiration of starchOOOO
PEP CarboxylaseOOOO
RuBP CarboxylaseOOOO
ATP productionOOOO
ATP utilizationOOOO
CO2 fixationOOOO

19. In fusiform initial cells, cell divisions in the:

RADIAL plane produce _______________ cells.

TANGENTIAL plane produce ______________ cells.

TRANSVERSE plane produce ______________ cells.

20. The effects of auxin upon growth in a newly-discovered monocot seedling are shown below.

  1. based upon the graph above, place appropriate concentrations of auxin in the boxes at the positions appropriate for this new monocot shown at left.
  2. draw in the developing apex of a lateral root and of an adventitious root at the positions at left predicted from the graph above. Label the two apices.
  3. use a bracket to indicate the zones of elongation for the coleoptile and the root.
  4. if the seedling is placed horizontally, which organ will curve up?
       coleoptile     root   
  5. place an asterisk (*) at the site of auxin biosynthesis.
  6. If a piece of coverslip was inserted into the right side of the organ at the position of the *, and if it caused a 1000-fold drop in the IAA concentration on the side of the coverslip away from the source of the the auxin, the organ would:
       curve right     curve left     grow straight   
  7. If the whole seedling was placed in 10-6 M IAA, what process(es) would be stimulated?
       coleoptile elongation     root formation     root elongation   

21. Briefly describe the Munch hypothesis for translocation. You should describe what is going in, what is going out, how this is accomplished, and where it is happening.

Tell what is happening in the source organ.





Tell what is happening in the translocation pathway.





Tell what is happening in the sink organ.





22. Name the four physical components of transpiration contributing to the ascent of sap up a tall tree and describe each.

23. Here is your first essay:

Describe the process of seed germination in barley including the role of gibberellic acid in stimulating germination. A diagram might be a wise way to respond to cover one-thousand words.

24. Here is your second essay:

Describe the process of seed germination in lettuce including the role of various colors of light in stimulating the process. A small diagram might be helpful. Be sure to include the effect of various light sequences on germination.

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