National Numeracy Network > Teaching Resources > Quantitative Writing > Examples > Goldenrod Gall Flies: Writing a Lab Report in the Form of a Scientific Paper

Goldenrod Gall Flies: Writing a Lab Report in the Form of a Scientific Paper

This page authored by Sarah Deel, Carleton College, Northfield, Minnesota. The lab activity was designed by the Carleton Biology Department.
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This material was originally developed as part of the Carleton College Teaching Activity Collection
through its collaboration with the SERC Pedagogic Service.


In this biology lab, students investigate whether goldenrod gall fly larvae collected from restored prairie area are different from larvae collected from a small native prairie 10 km away. They look for biochemical differences in proteins using cellulose acetate electrophoresis. Students determine the genotype of each gall fly; students compare the combined class' genotypes for the two groups of gall flies statistically using chi-square analysis. Students read a related scientific paper and discuss it in a subsequent lab session. Students write a full lab report describing their results using standard scientific paper formatting. A detailed description of this format and the writing process is provided.

Learning Goals

Context for Use

This laboratory activity is used in labs for an introductory college biology course at a small, liberal arts college. The lab allows students to address a legitimate scientific question by collecting local organisms in the field, looking at biochemical differences, analyzing numerical data with statistics, and synthesizing their results within the context of previously published papers. Lab size is limited by equipment; in our labs, 24 students, working in groups of 3, successfully share 4 gel-loading systems. Data collection can be accomplished in a 3 hour lab period, not including time for collecting material in the field.

The technique of cellulose acetate electrophoresis is extremely flexible, and can be used on any local organism. For more information on this technique, see the Association for Biology Laboratory Education Lab: "Measuring Genetic Variability in Natural Populations by Allozyme Electrophoresis" by James M. Bader.

The associated guide for writing lab reports is a general resource which could be useful in many contexts.

Description and Teaching Materials

Flow of the Lab Project:

Teaching Notes and Tips

We chose to study goldenrod gall fly larvae because the live organisms can be collected in the field in the fall and winter in Minnesota. The technique is extremely flexible and can be used to compare populations of many organisms. Part of the beauty of the technique is the ability to take students into the field for organism collection, do biochemical analysis of the organisms, and answer evolutionary questions about them.

Cellulose acetate electrophoresis is simple, but the equipment and gels are expensive. One source is Helena Laboratories in Beaumont, Texas; they also have an excellent reference book on cellulose acetate electrophoresis.

One challenge is to convince students to make use of the Lab Report Guide as a resource. The Guide's format is designed to be student-friendly, with short summaries of what belongs in each section followed by lengthier FAQ-style information. Students often realize the benefits of using the Lab Report Guide after they receive grades on their drafts of Materials and Methods and Results sections.


Students are assessed along the way over several scaffolded assignments. Grading rubrics are available for the lab report; contact the author for details.

References and Resources

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