University of Washington, Seattle

BIOLOGY 180

RQ00- Experimental Design

1)What is the difference between a hypothesis and a prediction?

2. Which of the following is a prediction based on the cell theory that all organisms are made of cells, and all cells come from preexisting cells?
3. What was important about the experimental design for Pasteur's flask experiment?
4. How do biologists test their ideas about the natural world?
5. Why is it important to perform multiple trials in an experiment -- meaning that you include many test individuals or samples?
6. The remaining questions refer to this situation: Researchers do an experiment to test the hypothesis that Douglas fir trees put more resources into reproduction when they are infected with a fungus that causes a fatal disease. They establish study plots in a group of 50-year-old Douglas fir where the disease is not present. At random, they infect half the trees with the disease-causing fungus. Then they measure how many cones and seeds are produced by infected versus uninfected trees.

What prediction follows from the hypothesis?

7. Which treatment would be considered the control?
8. Why is it important to do the experiment in the same group of same-aged trees?
9. Why is it important that they assigned trees to the infected versus uninfected groups at random?
10. If the hypothesis is wrong, and being infected with the fungus has no impact at all on reproduction, what should they observe?