Plants & Human Affairs - Introduction
Cherries.wmf (7140 bytes) Plants & Human Affairs (BIOL106)  -  Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321;;

Study Guide for Essential Oils


  • allelopathy
  • enfleurage
  • essential oil
  • fixed oil
  • Grease Spot test
  • pheromone
  • volatile oil

Questions - General:

  1. Define essential oil.
  2. What is the difference between an essential and a fixed oil? Can you give examples of fixed and essential oils?
  3. What is the grease spot test?
  4. Are essential oils soluble (dissolve) in water?
  5. Why do plants produce essential oils?  What are some of the functions of the oils in the plant?
  6. What is allelopathy?
  7. Humans have used essential oils and essential oil-containing plants in many ways.  Identify several.
  8. Identify hypotheses to explain why humans have included spices/herbs in food.
  9. Identify hypotheses to explain why humans apply perfume/cologne?
  10. How do humans perceive odors? 
  11. What is a pheromone?  Give some examples.
  12. Do humans have pheromones?  Provide some evidence for the existence of pheromones in humans.
  13. How might humans perceive pheromonal signals?
  14. For each of the methods used to extract essential oils (solvent extraction, effleurage, distillation, expression): describe it, indicate the pros and cons and name a plant extracted by that technique.

Questions - Spices:

  1. What is the role of spices in global colonization?
  2. Compare and contrast the use of the words:  herb, spices and seeds
  3. Name two spices that come from different parts of the same plant.
  4. Is capsicum pepper the same as black pepper?
  5. How is vanilla produced?
  6. Red peppers are associated with Szechwan cooking, cumin and coriander with Mexican cuisine and paprika with Hungarian cooking.  Have these associations always existed? Explain.
  7. Compare and contrast cassia and zelandica cinnamon.

More Spices:  For each of the following spices, be able to describe: (a) region of origin/production; (b) how it is used; (c) type of plant from which it is produced (herb, tree, shrub) and (d) part of the plant from which the spice originates.

  • allspice
  • cardamom
  • carrot family (parsley, dill, cilantro, coriander, fennel, cumin, anise, celery, caraway)
  • cinnamon
  • cloves
  • garlic/onion/leek/chive
  • ginger
  • horseradish
  • mint family (rosemary, thyme, oregano, marjoram, sage, peppermint, spearmint)
  • nutmeg/mace
  • pepper - black & white
  • pepper - Capsicum
  • saffron
  • turneric
  • vanilla

Questions - Perfumes:

  1. Name some plant families with many species that produce essential oils.  What are some of the characteristics of these families.  Can you name several plants I each family that provide spices/oils.
  2. What is ambergris?
  3. What is myrrh?
  4. Wintergreen oil comes from a tree.  True or false?
  5. What are fixatives and why are they important?  Can you name some?
  6. Which has the greater concentration of essential oils � toilet water, cologne, perfume?
  7. Explain why the best perfume container is a small brown jar that can be tightly sealed?
  8. Identify some of the uses of perfumes
  9. What is an odorant? Concrete? Absolute?
  10. How is perfume making like making music?
  11. True of false:  Most of the money required for the development of a new perfume goes toward growing and purchasing plant materials.  Explain.

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Last updated:  11/30/2005     � Copyright  by SG Saupe