Study Guide | Explore This Topic | Meet the Scientist
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Explore This Topic

Check Your Understanding

The following questions accompany this lesson. The answers are given below each question. To reveal an answer, place the cursor over "REVEAL THE ANSWER".

1. a). What is a model organism?
   

   b). Give at least six examples of common model organisms.
   

2. Make a list of the ways communication and interactions between scientists are important in the progress of science.
   

3. Describe the placebo effect and what can be done to avoid it.
   

4. Advertisers often make use of testimonials to promote products. For example, they might have a beautiful supermodel toss her mane of silky hair and exclaim that it is beautiful because of this wonderful shampoo, or they might have a famous celebrity tell you how a new medication changed his life. Obviously advertisements are biased because advertisers have a vested interest in selling you a product, but even testimonials from friends should be treated with caution. Explain why based on what you have learned about the process of science.
   

Exercise Your Brain

1. a) In the lesson video, Dr. Spitzer explains the importance of model organisms and gives several examples: fruit flies, nematode worms, zebrafish, frogs, mice and rats. According to Dr. Spitzer, what are the advantages of using frogs to understand the development of the nervous system? What might be some possible drawbacks of using frogs as model organism?

   b) In the Perception: Taste, Smell and Vision lecture, Dr. Zuker describes his research on taste perception in mice and his research on touch perception/equilibrium in fruit flies. Why might he use different organisms to study these different questions? Would it be possible to use mice to study touch and flies to study taste? Why or why not?

   c) If you could design the perfect model organism for neuroscience research, what would be the characteristics or features of your model organism? What characteristics would you not want it to have? Explain your rationale. For background you can peruse an extensive list of existing model organisms at Wikipedia.

2. A group of researchers is setting out to determine the mechanisms by which humans detect pheromones. Pheromones are similar to hormones except that they are released outside the body and are used for communication between animals. The (well-funded) scientists have a wide range of tools available to them:
   • a selection of model organisms;
   • isolated, purified pheromones from humans and various animals;
   • undergraduates willing to participate in painless experiments for a small compensation;
   • equipment necessary for different kinds of brain scans;
   • the ability to genetically alter certain model organisms, including the ability to make select nerve cells fluoresce; and
   • healthy cells from different parts of the brain in individual Petri dishes.

   Partner with one or two classmates and come up with ideas for three different experiments you could do to gain more understanding of how pheromones are detected, for example what cells detect them and/or how the information is sent to the brain. Indicate:

   1. What question you are trying to answer in each experiment.
   2. What would be the main challenges of the experiment?
   3. How might the results of the three experiments fit together to give you a bigger picture?

3. “Extraordinary claims require extraordinary evidence.” This maxim is usually attributed to the famous astronomer and author, Carl Sagan.
   1. With a partner, brainstorm some extraordinary claims you have heard. What evidence is there that the claims are true? Do you believe the claims? If not, what evidence would you need in order to believe them?
   2. The history of science is full of revolutions in thought, in which what were once thought to be extraordinary claims became widely accepted. Choose one example of something that was once considered an extraordinary claim, but is now accepted (or at least reasonably well-accepted) by the scientific community. Conduct some research to determine what evidence led to the acceptance of the claims.

   Possible examples include:

   • Continents drift;
   • Some viruses can cause cancer;
   • A protein alone can transmit disease (prions and mad cow disease);
   • Certain genetic material can move around the genome (jumping genes); and
   • Diseases are not caused by spontaneous generation (germ theory of disease).