Plant Hormones

After reading pages 444-447 in Addison-Wesley, answer these questions in complete sentences.

  1. Define hormones.
  2. Describe (define) an auxin's effects on plants.
  3. Explain how the Darwins and Went used oats in their investigation of auxins.
  4. The most abundant naturally occurring auxin is _____________________.
  5. Explain why 2,4-D is used as an herbicide.
  6. Would 2,4-D be a good choice for killing the grass growing in the cracks of the student parking lot? Explain.
  7. Describe (define) a gibberellin's effects on plants.
  8. Even if it didn't die, why would it be a problem if your rice plant fell over?
  9. Do plants have their own gibberellins or are they found only in that fungus?
  10. If you were growing grapes would a gibberellin spray be useful for you? Explain.
  11. Describe (define) a cytokinin's effects on plants.
  12. Make (two) labeled drawings showing the interaction of auxins, cytokinins and apical dominance.
  13. Describe ethylene's effects on plants.
  14. Give an example of ethylene's use in horticulture.
  15. Describe abscisic acid's effects on plants.
  16. Some seeds of desert plants have abscisic acid in their seeds. What function might that chemical perform?