1. Write a specific research question on the topic described in the paragraph above. (1pt)

2. Identify the independent and dependent variables in your hypothesis (include units of measurement where appropriate). (2pt)

Independent Variable: _____________________________________________

Dependent Variable: ______________________________________________

3. Explain why you have selected the independent and dependent variables you indicated above. If you draw on research from outside sources, be sure to cite them. (2pt)

4. Write a testable null and alternate hypothesis to answer your research question. (4pt)

Null Hypothesis:

Alternate Hypothesis:

5. In an experimental design, it is important to consider variables other than the independent variable that might have unintended effects on your dependent variable. Suggest one such variable (other than human or equipment errors) and explain why it could have unintended effects on your results. How would you control for this error? (2pt)

6. Describe an experiment you would conduct to test your hypothesis from question four. This will be assessed based, in part, on the thoughtful inclusion of the major components of experimental design we discussed both in lab and in lecture. For full marks, the experimental design must be described in enough detail that another scientist could repeat the experiment exactly as described. Try and include as much detail as possible, including any variables to be kept standardized. (10 pt)

7. What result would you predict if your alternate hypothesis is supported by your experiment? Draw a graph that clearly shows this imagined result of your specific experiment. (4pt)

ILJ Experimental Design Assignment Group Members' Names: Lab Instructor: Lab Section: After graduation from KPU, you start a new job working in the Environmental Toxicology lab for the National Research Council Canada. Your first assignment is to determine the ongoing impact of a rail accident in the Fraser Valley of British Columbia. Ten years ago, a train carrying mine tailings derailed, spilling a sludge of heavy metals including cadmium (Cd), copper (Cu), arsenic (As), and lead (Pb) into a river used as an irrigation source for local farms. Several crops were irrigated with the polluted water source before the irrigation systems could be shut down and rerouted to another water source. Unfortunately, heavy metals can remain in the soil for decades after they are introduced and, depending on the concentration, can have serious detrimental effects on both plants and the animals that eat them. Your department colleagues collected data on heavy metal concentration in farm soils 50 Km upstream (I.e. from a location in the opposite direction of the flow of the river) and at the crash site earlier this year (Table 1). Table 1. Heavy metal concentration in farm soils. Concentration (mg/kg) 50 Km Crash Site upstream 3.7 2.9 1648.9 3.8 1205.7 19.6 57.2 Metal Cadmium Copper Arsenic Lead 9.8 Your team has been assigned to select the heavy metal that you think is of greatest environmental concern and determine its effect on growth in corn plants, Zea mays, the most abundant crop species in the area. The life cycle of Z. mays has been provided for your reference (Figure 1). The goal of this research is to determine an acceptable concentration of your chosen heavy metal as a soil remediation goal. Other teams will be doing parallel research to determine its effects on humans and wildlife. Tasselling Silking Maturity Stage Pollination Emergence 2 leaves 5 leaves 8 leaves 12 leaves 16 leaves 20 fully fully fully leave emerged. emerged. emerged. Tassel and ear initiation Planting Assignment: Work with your assigned group to design an experiment to test the effect of one of the heavy metals identified (Table 1) on growth in Zea mays. You must agree upon which heavy metal you want to research, whether your experiment will be conducted in the laboratory or in the field, and how and when you will measure your dependent variable. Be sure to discuss and agree upon a strategy before answering the following questions. There is not one "right" answer. Your group will be assessed both on the application of experimental design principles and on the demonstration of critical thinking in your design. All group members will participate in the production of one completed assignment for submission following the instructions provided by your lab instructor The use of outside resources is permitted, though not required. Even if you do choose to do additional research, the experiment you describe must be your own unique design. If you do use outside sources, cite them using APA style in a Literature Cited section at the end. 1. Write a specific research question on the topic described in the paragraph above. (1pt) 2. Identify the independent and dependent variables in your hypothesis (include units of measurement where appropriate). (2pt) Independent Variable: Dependent Variable: 3. Explain why you have selected the independent and dependent variables you indicated above. If you draw on research from outside sources, be sure to cite them. (2pt)