Learning science is not simply mastering a body of factual material and learning about "the scientific method." Learning science is participating in science: asking a question, framing a hypothesis, designing and carrying out experiments, evaluating whether the experimental evidence supports the initial hypothesis, and finally communicating the results. Often further experiments and even hypothesis revision are needed.

The two kinds of organisms that we use -- planaria and legume seeds --are robust and are suited to simple, low-tech, laboratory investigation. Legumes such as peas and beans have considerable reserves of nutrients stored in the cotyledons that make them easy and quick to grow. Planarians have a thin epidermis and they are affected quickly by substances dissolved in the water of their environments. It is easy for the students to conceive of questions concerning the environment, pH, pollution, temperature, etc., that might affect seedling growth or survival of flatworms. The following are topics that have been successfully carried out by students in past semesters; there are a few untried suggestions.

Ideas for Group Research Projects

1. In the catabolism exercise, we will observe that germinating pea seeds produce carbon dioxide gas, which we will detect using phenol red as a pH indicator. Dry pea seeds do not produce carbon dioxide, but dried pea seeds that are soaked in water for even a short time begin to catabolize stored carbohydrates and form carbon dioxide. Their ability to catabolize carbohydrates is a sign that they are alive. Does freezing kill pea seeds? Does heat kill pea seeds? Are wet seeds more easily killed than dry seeds?
2. Some seeds, like peas and beans, have plump, nutrient rich cotyledons. Others, like radishes or dandelions, have tiny seeds. What difference does the amount of stored nutrient make for germination and survival of seeds?
3. Oceanic islands that are far from continents are covered with plants. Even new islands formed by volcanoes are rapidly colonized over water by plants and animals. How long can seeds float and be transported by ocean currents? How long can a seed soak in sea water and still germinate if it washes up on the shore of an island?
4. Calcium chloride (a salt) is used to melt snow and ice on roadways and sidewalks in the winter. How does calcium chloride affect the growth of plants? Does it inhibit seed germination? Does it inhibit plant growth after germination?
5. Detergents, bleach, and other household cleaning products contaminate the water of soil, streams, and ponds. How do these products affect the survival of small plants and animals?
6. In the laboratory exercise on organic molecules, you will learn to test for reducing sugars, starch, lipids, amino acids (free amino group), and proteins (peptide bonds).
a. Does the type of carbohydrate (sugar or starch) differ in various plant parts such as fruits, leaves, tubers, and bulbs? What are reasons for the differences?
b. Does the amount of light a plant receives affect the amount of starch stored in its leaves?
7. What is the effect of light on photosynthesis and starch storage in Spirogyra?
8. What stimulates cell streaming in Elodea?
9. Temperature is an important environmental factor for most organisms. How does temperature restrict the habitat of planaria (a free-living flatworm)? How does temperature affect its behavior (mobility, feeding, etc.)?
10. Light is an important environmental factor for many organisms. How does light restrict the habitat of planaria (a free living flatworm)? How does light affect its behavior (mobility, feeding, etc.)? Will planaria swim toward light or away from light?
11. Most aquatic organisms live in freshwater or sea water; some can tolerate the salinity fluctuations of brackish water environments such as river estuaries. Can planaria live in ocean water, in brackish water? How much salt can planaria tolerate in its environment? Does the presence of salt alter the behavior of planaria?

These experiments were designed by students and faculty for NSF Grant # DUE-9354712.

Guiding Student Research

The following is an outline for problem solving that has come to be known as the scientific method. It depends on the clarity of questions asked and on predicted outcomes that can be observed. Group projects are a collaborative effort done mostly outside of regularly scheduled class time, though students may have time during the laboratory period to make observations and talk together as a group. It is important that every student participate equally in all stages and take full responsibility for some aspect of the experiment and oral presentation.

• Decide on a research problem.
• Collect and read relevant articles or textbooks for background and context.
• State a hypothesis (keep it simple).
• Make predictions based on your hypothesis that you can test.
• Design experiments that test the predictions; don't forget the control(s).
• Prepare the experimental setup; request equipment as needed.
• Make measurements or observations, and record the data as you make them.
• Review and discuss the results in your group.
• Repeat the experiments; modify your experimental design, if necessary.
• Evaluate the hypothesis based on your experimental results.

Get a form for planning your project

• Discuss and decide how best to present your results to the class.
• Summarize the results in table(s); prepare graphs of the data if appropriate. Make a rough draft and check visibility of content to students in the back of the lab room.
• Prepare a brief handout (no longer than 1 page double-sided) for distribution to the class.

The oral presentation is worth 5 points (all members of a group receive the same grade) based on the following criteria:

1. quality of experimental design
2. care in execution of the experiments
3. clarity of the oral presentation
4. aptness of the handout
5. demonstration of competence in the question and answer session

Exception: Failure to show up or to participate in the oral group presentation earns a student zero points on that part of the course grade.

The written paper is worth 5 points; instructors may request a single paper from each group or a paper from each individual in each group. Include the following:

1. Title -- What is the subject of your research?
2. Introduction -- What is interesting about the topic you selected?
   What was your group’s hypothesis?
3. Methods and Materials -- What was the design of your experiment; how was it set up and how often did group members monitor its progress and record the results? The goal of this section in a scientific paper is to make it possible for others to repeat your experiment and thereby find out if the outcome is reproducible.
4. Results -- What were the results: tables of data and description; number and title each table.
5. Discussion -- Explain fully whether your results support your hypothesis and to what degree. Refer to your tables of results by number.
   With the experience of a completed project, can you design a better experiment to test your hypothesis?
   Would you now modify your original hypothesis? If so, how would you test it?
6. Conclusion -- Briefly restate the relationship of results to hypothesis and tell the importance of this research to the larger world.

• Completing all parts of the assignment
• Demonstrating scientific reasoning
• Communicating ideas clearly
• Using correct English grammar and spelling

This project was supported, in part, by the National Science Foundation Opinions expressed are those of the authors and not necessarily those of the Foundation

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