Question Sheet: Spit Power


Before reading:

  1. Why do people produce saliva?
  2. What problems might you run into if salivary glands in your mouth failed to

    produce saliva?

During reading:

  1. In what way is saliva like water? In what way is it different?
  2. What do proteins in saliva do?
  3. How does a lack of saliva affect people?
  4. Why might someone not have enough saliva?
  5. How is the DNA in saliva useful to scientists? To crime scene investigators?
  6. Describe Navazesh’s interest in the relationship between cavities and


After reading:

  1. Why do you think people produce a lot of saliva? See (Oral Cancer Foundation).
  2. To diagnose diseases, test for drugs, and obtain other clues about human

    health, researchers can use samples of blood, urine, or saliva. Which type of

    sample is easiest to obtain? Why? Why is it often harder to get the information

    that’s needed from a saliva sample? See (American Association for the Advancement of Science).

  3. Dentists do more than just check and repair your teeth. Some do dental and

    other research (see, for example, “A Whale’s Amazing Tooth”). What projects not strictly related to working in a dentist’s office might a dentist undertake? See Institutes of Health).

  4. How does saliva change when you are hungry? When you are sick? What other

    factors might affect saliva? See

    (Oral Cancer Foundation) or


  5. Why would someone devote his or her life to studying saliva? Is Navazesh’s

    work important? Why or why not? See and (University of Southern California).


What is rabies? What role does saliva play in the transmission of rabies? Who was the first person to receive an effective shot for rabies? When did that happen? See (Centers for Disease Control and Prevention).


  1. When Navazesh calls saliva “a fountain of opportunity,” she is making a joke

    about saliva as a liquid. Come up with two of your own jokes about saliva.

  2. How might a criminal get caught through saliva DNA evidence? Write a short

    scene that features a detective at a crime scene looking for this evidence.


Suppose that you put 9 milliliters of distilled water into a test tube. Then you add 1 milliliter of food coloring and mix it with the water. Next, you take 1 milliliter of this mixture and add it to 9 milliliters of water in a second test tube. After mixing, what is the

concentration of food coloring in the second test tube? Express the concentration in parts per million.