deborah verhoeven north salinas high school, salinas, ca 93906 contact information...
TRANSCRIPT
Deborah Verhoeven • North Salinas High School, Salinas, CA 93906
Contact Information
Conclusion/Lessons Learned
There is a lot of interest among students in forensic science currently because of television shows like CSI. I decided to introduce students to the process of using micropipettes and doing electrophoresis with a DNA Fingerprinting simulation and follow up lab to capitalize on their interest. The student worksheet shows the number of DNA pieces and the distance that they migrated during a simulated electrophoresis process. I separated the results for each suspect on a different page of the worksheet so that the students had to use their measuring skills to determine which suspect matched the crime scene. Students were very focused during the lab, and excited to be able to successfully complete the lab techniques involved in DNA Fingerprinting. Doing the simulation activity prior to the lab greatly increased student understanding of the process and application of DNA Fingerprinting.
The summer Marine Biotechnology and Bioinformatics workshop allowed me to learn the laboratory techniques that I needed to teach to my students, as well as gave me a chance to learn more advanced lab techniques such as Polymerase Chain Reaction and DNA Sequencing.
Instructional Goal
The goal of this lesson is to:• Understand the process of DNA
Fingerprinting.• Know how DNA Fingerprinting is used in
solving crimes.
Instructional Objectives
Upon completion of this lesson, students will be able to:
• Analyze electrophoresis results from DNA Fingerprinting.
• List three applications for DNA Fingerprinting.
Introduction/Background/Context
DNA Fingerprinting is a very useful tool in solving crimes. Many classrooms do not have the equipment to do a restriction digest and electrophoresis experiment. This activity will allow the students a chance to simulate the process of analyzing the results of DNA Fingerprinting.
The students will be given a crime scenario that contains DNA results from blood collected at the crime scene. They will analyze the electrophoresis results from three suspects and crime scene DNA to determine who committed the crime.
This biotechnology activity fulfills the California Science Standard 4 on DNA and Standard 5d on DNA technology.
This biotechnology activity fulfills the National Science Standard C on molecular genetics.
STEM Connection. This activity will help students learn more about the following careers: Forensic science, lab technician, and molecular biologist.
Method
• Students will read the crime scenario.
• They will then visit the following website to get background on DNA Fingerprinting:www.biotech.iastate.edu/biotech_info_series/bio6.html
• Students will analyze the electrophoresis results from three suspects and the crime scene.
• Using the electrophoresis analysis, students will determine who committed the crime by comparing the crime scene DNA Fingerprinting results to their analysis of the three suspects.
• This activity can be used as a precursor to a real electrophoresis lab if the proper equipment is available. EDVOTEK offers an easy to use DNA Fingerprinting kit.
Results/Learning Outcomes
• Students measured the distance that each DNA fragment moved from the starting position for each of the three suspects.
• Students successfully determined which suspect committed the crime by comparing the three suspect measurements to the crime scene measurements.
• The DNA Fingerprinting simulation activity was followed by a DNA Fingerprinting lab. The students applied their knowledge of the process of DNA Fingerprinting and were able to solve the crime by analyzing their electrophoresis results.
The equipment that is needed to do the DNA Fingerprinting lab kit. Moving clockwise from the top the items are: an electrophoresis chamber, a power supply box, a micropipette, a test tube rack, and a microcentrifuge.
This image shows the electrophoresis results from the DNA Fingerprinting lab offered by Edvotek. The first lane shows crime scene DNA cut with the first restriction enzyme. It is compared to lane three (suspect 1) and lane five (suspect 2) which contain DNA cut with the same enzyme. The crime scene DNA in lane two is compared to lane four (suspect 1) and lane six (suspect 2). Suspect two committed the crime because the results from both enzyme match the crime scene DNA.
Eduardo Solis at North Salinas High
School loading DNA samples for DNA
Fingerprinting.
Ariel Noguera at North Salinas High School preparing for the electrophoresis of DNA samples.
DNA Fingerprinting Simulation
A sample page from the student worksheet for the DNA Fingerprinting Simulation.
Eva St. Onge • Bradwell Institute, Hinesville, GA 31313
CONTACTEva St. Onge
Biology and Oceanography Teacher, Bradwell Institute
100 Pafford Street, Hinesville, Georgia 31313
CONCLUSIONThis student-oriented lesson is effective in promoting contextual learning as an enhancement activity. Prior knowledge of students plays an important role on the learning outcome, thus an acquisition lesson is essential prior to the activity.
Students with higher level of understanding in the content find the activity interesting and challenging, while students with lower level of understanding struggle to complete the tasks. Students who have difficulty in this activity should be provided with shorter strands of the DNA sequences to practice the amino acid translation process. Grouping structure may be designed to pair up peer tutors with students who need help.
A good follow-up activity to reinforce concepts learned in this lesson is inferring the consequences of changing one of the nucleotide bases, and the consequences of inserting or deleting one of the nucleotide bases. This follow-up activity will lead to a subsequent lesson that discusses the various types of mutation, such as point mutation and frameshift mutation.
INSTRUCTIONAL GOAL Engage students’ curiosity
Promote problem-solving skills
Learn the molecular basis of gene expression
Enhance computer literacy in bioinformatics by using online databases to search for scientific information
INSTRUCTIONAL OBJECTIVES Translate DNA nucleotide sequences into mRNA
codons and then to amino acid sequences
Search online bioinformatics databases as a process in scientific inquiry
Use scientific knowledge and logic to solve problems
BACKGROUNDThis lesson requires students to use knowledge in translating DNA sequences into amino acids, and skills to search online database for the source of these amino acid sequences, in order to solve a murder case.
State Standards
State of California Biology 4 Genes are a set of instructions encoded in the DNA sequence of each organism that specify the sequence of amino acids in proteins characteristic of that organism.
State of Georgia Performance Standards Biology 2 Students will analyze how biological traits are passed on to successive generations.
National Standards
Science Content Standard C Students should develop an understanding of the molecular basis of heredity.
STEM Connection
Careers tied to this activity include bioinformatics researcher, clinical or medical geneticist, genetics laboratory technician, forensic scientist, and crime scene investigator.
METHOD Ensure students have the prior knowledge of gene
expression by the processes of transcription, translation, and protein synthesis.
Introduce students to the scenario of investigating a murder case in which three DNA samples are extracted on the victim’s body.
Students perform the following tasks:
o Transcribe the DNA sequences into mRNA codons
o Translate mRNA codons into amino acid sequences
o Conduct online bioinformatics search to identify the protein coded for by each DNA sample
o Determine which sample belongs to the killer
LEARNING OUTCOMESA pre-test and a post-test are administered to assess the students’ gain in gene expression content knowledge, and their general ideas about bioinformatics and biotechnology. In addition, students complete surveys after the lesson to provide feedback on their learning experience. Analysis of the results in the tests and survey yields these data:
80% of the students demonstrated gain in the content knowledge of gene expression
68% of the students demonstrated increased knowledge in bioinformatics and biotechnology
64% of the students felt that the student worksheet had sufficient instructions to guide them through the activity
37% of the students felt that this activity was fun
49% of the students felt more confident in using computer technology after this activity
17% of the students thought this activity increased their interests in bioinformatics or biotechnology careers
37% of the students thought this activity increased their interests in STEM careers
MATERIALS/ RESOURCES Student worksheet
Student assessment (pre-test and post-test)
Student survey
Computers with Internet access
http://www.ncbi.nlm.nih.gov/BLAST (Bioinformatics search)
http://www.accessexcellence.org/RC/VL/GG/genetic.html (Translating mRNA codons to amino acids)
http://www.biochem.ucl.ac.uk/bsm/dbbrowser/c32/aacode.html (Looking up single-letter Amino Acid codes)
Sampler of student feedback on this lesson collected from the survey.
Students’ gains and losses in their knowledge before and after the lesson, based on scores in pre-test and post-test.
Screen shot of NCBI BLAST webpage, the online bioinformatics
database that we use in Part 3 of this activity.
Students enter the 20 amino acids they decode
in Part 2 of the activity into this database to find out
the protein they code for.
Students work in groups of 2~4 to perform bioinformatics search in order to solve a murder case. A computer with internet access is shared among each group.
Blast that DNA!
A worksheet is prepared for students to process information and record data. Here is a student work sample with teacher commentary.
Gene Expression
Students having a gain in
knowledge 80.36%
Students having a loss in
knowledge 5.36%
Students having the
same knowledge
14.29%
Gene Expression
Students having a gain in
knowledge 80.36%
Students having a loss in
knowledge 5.36%
Students having the
same knowledge
14.29%
Biotechnology and Bioinformatics
Students having a gain in
knowledge 67.86%
Students having a loss in
knowledge 8.93%
Students having the
same knowledge
23.21%
Biotechnology and Bioinformatics
Students having a gain in
knowledge 67.86%
Students having a loss in
knowledge 8.93%
Students having the
same knowledge
23.21%
Total students=57 Total students=57