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Dinosaur and DNA Days

By Richard P. Filson



(Modified and adapted by Richard P. Filson from the Biotechnology Education Program, Lawrence Livermore National Laboratory)

Type of Entry

  • Unit outline

Type of Activity:

  • Hands on Activity
  • Simulation
  • Inquiry lab
  • Group/cooperative learning
  • review/reinforcement
  • Community outreach
  • Interdisciplinary
  • Authentic assessment

Target Audience

  • Biology

Background Information

Goals:

  • Demystify biotechnology.
  • Create an awareness of the present and future impact of biotechnology.
  • Increase understanding of the relationship between science, technology, and society.

Student Outcomes: students will . . .

  • Increase their comfort level with biotechnology and its applications.
  • Effectively communicate their understanding of biotechnology in written responses to open ended questions.
  • Examine biotechnology and its implications from varying perspectives.
  • Apply scientific knowledge and skills to examine and solve problems relevant to their lives.
  • Gather and analyze data and/or use models to resolve issues generated by biotechnology.

Notes to Teacher

This biotechnology unit presumes that students have previously studied cell theory, simple biochemistry, and genetics with an introduction to the chemistry of DNA. The class time needed to carry out the various activities and provide direct instruction is about 2-1/2 to 3 weeks. Some advanced planning is required. You will need to know exactly when you will carry out investigations on samples of DNA, and live bacteria. These must be ordered in advance and must arrive in a timely fashion. Proper cold storage is required. Preparation of petri dishes of agarose requires extra time after school. Furthermore there are several equipment considerations for each lab as will be noted in the activity outline.

This unit was designed to be taught in conjunction with a much larger all school interdisciplinary unit on biotechnology which is taught each year at my school in a spiraling curriculum. However, the biology unit is self contained and can be implemented successfully by a single teacher. What is lost in the self contained classroom is the scope of the breadth and to a lesser extent depth at which biotechnology can be viewed. The more disciplines that are integrated into the unit, the more connections are made and deeper learning occurs.

The interdisciplinary extensions of the biotechnology units are quite broad. The English classes read books like Jurassic Park by Michael Crichton and Frankenstein by Mary Shelley. Analysis and discussion of these stories as literature spawn a wide range of student assignments. (Before the English department embraced this all school approach, my students earned extra credit for reading and discussing either of these two novels. Thanks to LLNL, I had several dozen copies of the paper backs for loan). Social studies teachers find many relevant issues of biotechnology to explore in their classes including law, ethics, privacy, and social impact of biotechnology. The math teachers can get involved by using the Hardy-Weinberg model and probability.

Other curricular dimensions which became part of our Dinosaur and DNA Days theme were the applied and performing arts. Art classes made DNA models, dinosaurs sculptures, silk screened t-shirts, posters, etc. The drama classes wrote and performed plays that emphasized a genetic theme such genetic counseling, genetic therapy, or genetic engineering. Vocational arts such as drafting designed a gel box. Students in wood/plastic shop actually fabricated a working prototype for the science classes. This equipment was as good if not better than commercial versions and was very reasonably priced. The communications classes included a biotechnology question in the daily bulletin for two weeks. Students submitting correct answers were eligible for a daily drawing for a prize.

All of these activities have been successful at my school. LLNL through its BEP program has produced a handbook that includes lessons for both science and non science disciplines. Included in the science section are laboratory activities appropriate for other science classes such as physics, chemistry, AP Biology, life science, LEP classes are also included. The unit outline that follows is limited to sophomore college prep biology.

Abstract of Activity

This is a unit on biotechnology whose primary goal is to demystify biotechnology and bring it down to the level where a literate citizen can understand its principles, general techniques, and potential applications. The outcome of this unit is for students to become conversant enough to discuss the problems and implications of such applications as genetic engineering and to arrive at logical conclusions independently. These outcomes are accomplished by providing students with a series of hands-on experiences with actual DNA, biotechnology tools, a simulation, videos, open ended writing assignments, and pre and post assessment tools.

Students gain experience by spooling DNA from beef thymus, learn the techniques of measurement with the micro pipette, and learn the principles of separation by using a gel electrophoresis box to separate and analyze restricted DNA, transform a bacterium using a genetically engineered plasmid. Reinforcement of genetic engineering is accomplished by carrying out a paper cut-out simulation of gene splicing. NOVA videos, The Real Jurassic Park and Murder, Rape, and DNA are used to stimulate discussions on science, technology, and society. The unit culminates in a laboratory in which students try their hand at inserting a plasmid into bacteria.

Activities/Materials

Activity 1: Spooling DNA

In this activity, students learn the ordinariness of DNA as well as its physical and chemical properties. A generic procedure for extracting DNA requires fresh or fresh frozen beef thymus (available from local meat packers). Students grind a small sample with sand and filter with cheese cloth. Students prepare a slide using a nucleostain to verify nuclei are released from the cell. A few drops of liquid dish washing detergent are added to the filtrate and mixed by tapping. Once the detergent breaks down the nuclear membrane, DNA is released from the cells causing a thickening to occur. Rubbing alcohol is then slowly poured down the side of the test tube and the DNA precipitates out. A hooked glass probe is used to wind up the threads of DNA. Students feel DNA's consistency, test its pH, and observe its structure and staining properties under the microscope. (Time needed: one class period.)

Activity 2: Using the Micro Pipette

In this activity students work in teams of two to practice and check one another on the correct method of measuring and dispensing with a digital micro pipette. Pipettes with a capacity of 20 µl and an accuracy of 0.1 µl are used. Water and food coloring are measured from 1.5 µl Eppendorf tubes and the food coloring is then dispensed into 2% agarose gel cast in petri dishes using a standard plastic comb to form the wells. This practice in gel loading provides skill for application to loading dyes and DNA for separation by gel electrophoresis which follow a few days later. (Time needed: one class period.)

Activity 3: Separation by Gel Electrophoresis

This activity is designed to familiarize the student with the principles of separation by gel electrophoresis. A set of dyes (Wards Science Establishment cat. #36W5254), 2% agarose with wells cast in the center of the gel tray, a gel box per two students and a power supply per four students are used for this activity. A buffer solution of 1XTBE is used in the agarose gel and in the gel box itself. Students observe that the different dyes move different directions and distances and deduce that electrical charge and molecular size are factors involved in separation by gel electrophoresis. (Time required: one class period.)

Activity 4: Analyzing Restricted DNA

I have used two approaches to analyzing restricted DNA. In the first, students follow the Ward's Restriction Analysis protocol for three restriction enzymes. On day one, enzymes are used to digest DNA samples. On day two, the restricted DNA is loaded into agarose gel and electrophoresed. The gel boxes must run into the next class period then the teacher must remove the gels, stain, and bag them for the next day. The third day is used to observe and measure the distances the restricted DNA fragments have moved. Students compare these distances to a DNA ladder, and deduce their molecular size. Students have had difficulty with the restriction procedure causing inconsistence results. Another alternative procedure is provided in the BEP handbook in which commercially pre-cut DNA is used. Students basically load the gels and analyze the results. The results of the second procedure have been very consistent. Only two days are needed.

Activity 5: Recombinant DNA Simulation

This activity is a derivative from BSCS, Advances in Genetic Technology, 1989, Heath. Students simulate making recombinant DNA. Students are given a plasmid map, a sheet with DNA sequences for a plasmid, a sheet with the DNA sequences for a cell. The construction of the plasmid is randomized by instructing students to discard a portion of the available strips and tape together the remaining strips in any order to form a loop. Students then tape together the cellular DNA sequence. Students are given a set of six palindromes for various restriction enzymes which are prepared on transparencies. They use the six restriction sequences to locate the best places to cut out a desired gene and splice it into the smallest recombinant plasmid they can form. (Time required: two class periods.)

Activity 7: Video: NOVA: Murder, Rape, and DNA and/or NOVA: The Real Jurassic Park

One or both of these videos can be used to stimulate student discussion of the principles and methods of biotechnology. Since each video has a running time of about an hour, it is recommended that two class periods be used for each. If both videos are used, the unit will take three full weeks. It is advised to separate these videos and place them in the unit to give yourself more preparation time between wet labs. I recommend that The Real Jurassic Park be shown first to review what is the technological reality for the story and what responsibilities would be assumed if someone could reproduce Jurassic creatures. I would show Murder, Rape, and DNA as a follow up to examine the social and legal implications of biotechnology. In both cases I provide students with prompts for written responses to reinforce the key points in each video. (Time required: two to four class periods.)

Activity 8: pBluTM Transformation of Escherichia coli Bacteria

The culminating wet lab for this unit provides the student an opportunity to introduce foreign DNA into another organism. The bacterium, Escherichia coli is the target of transformation. The commercial kit from Carolina Biological Supply Company call pBluTM Colony Transformation is used. This is an expensive, complicated procedure with several potential steps for error, however, the results are an excellent challenge for students to think critically. Each year, results seem to be better. Students see for themselves that organisms can receive foreign DNA that can express itself by giving the bacteria observable characteristics. (Time required: two class periods.)

Activity 9: Video (NGS filmstrip) Genetic Engineering

This is a National Geographic Society series involving two short filmstrips, "Changing the Genetic Code" and "Issues In Genetic Engineering" which serve as an effective review and reinforcement activity. (Time required: one class period.)

Extensions

The following activities are offered as extra credit assignments.

Book Reports: Jurassic Park by Michael Crichton, Frankenstein by Mary Shelley

Film Festival (After school): Jurassic Park, Frankenstein, Andromeda Strain, Lorenzo's Oil

Open House: students invite parents to an evening open house. Students demonstrate lab procedures and tools used in biotechnology. Local scientists have been invited to talk on biotechnology. A nice touch is to have the homemaking classes bake dinosaur shaped cookies for refreshments!

Evaluation

  • Pre and post test on attitudes about biotechnology.
  • Pre and Post-Open ended essay: What is biotechnology? How is it important to society?
  • Objective test of content and reasoning.

Additional Ideas

The most powerful aspect of this unit as it is implemented in my school is the hybridization of ideas between individuals in different disciplines. The non science staff really gained a new perspective on what good science teaching is about when these non science teachers were inserviced on all of the wet labs the students were to do. It certainly increased their comfort level with science as well as their respect for us as professionals. In addition, the joint efforts have opened a fruitful dialogue between the English and Science departments on good writing in science. The English and Social Studies departments are presently developing an additional interdisciplinary theme for the future, Renaissance Days. Science will be included, of course.


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