The list of television dramas depicting the world of Forensic Scientists, as seen on CSI (Crime Scene Investigators), Cold Case Files, 24, Bones, and The First 48, continues to grow. Although many forensic biotechnologist work involves a great variety of practices - fingerprint analysis, wound analysis, imagery and computer composite, document analysis, pathology, and genetic analysis - most popular media images exaggerate of the capabilities of this field and promote misleading and potentially damaging messages. This unit is designed to provide a starting point for capturing and expanding on student interest of forensic science using an authentic, problem-based learning approach. The foundation of the lesson is rooted in the 5E's Lesson Plan Pedagogy and its student-centered approach pairs well with the investigation of this engaging topic.
Students will utilize the latest technology in gene identification - DNA fingerprinting - to identify and trace a genetic disorder within the family of famed Russian czar, Nicholas II. In the process, they will learn more about how the use of DNA Technology has changed the way we approach crime investigation and has solved crimes, such as the Mystery of the Romanov Family, that had gone unexplained for decades! It may be best to review core practices used in DNA analysis such as DNA extraction, gel electrophoresis, and polymerase chain reaction (PCR) before beginning this lesson. Finally, due to the nature of the subject matter explored in this problem-based case, this lesson may be best suited for older students.
NATIONAL BIOTECHNOLOGY STANDARD(S):
BT.2.1, 2.2 - Describe the major scientific discoveries that lead to development of recombinant DNA technology, including those in the fields of biology, chemistry, genetics, and microbiology, and explain how these advances in DNA technology are used today.
BT. 6.4, 6.5 - Explain and demonstrate the principles involved in DNA analysis via agarose gel electrophoresis.
We begin the "Mystery of the Romanovs" lesson by engaging in a Diagram Dialogue routine in which students are asked to view a graphic and identify the trends, patterns and connections in a collaborative forum. The diagram analyzed is found on Page 1 of the Mystery of the Romanovs Student Lesson Guide. As students are encouraged to share their observations, their individual comments are recorded on a projected copy of the diagram and charted (oftentimes by a student volunteer) on our Genetic Testing Unit anchor chart and displayed in our classroom laboratory. Stay tuned for annotations made during the diagram dialogue of the illustration featured in this lesson. Until the actual diagram is posted, please review the following Sample Diagram Dialogue and view this short video of a student-led Diagram Dialogue routine. The following is a list of common questions asked during our Diagram Dialogue routine:
- Determine the setting of the diagram; where are you? Explain the overall scene in simple terms. What clues did you use?
- Who are the players? What characters, parts, structures, or components are being represented or depicted in the diagram? How do you know?
- Are there special characters, symbols (such as the circles and squares of the pedigree), shapes (such as triangles or enlargements)? What do they represent? How do you know?
- Are colors used intentionally? What do you think the use of color means? (For example, is the color intended to establish a relationship or distinction with components of the diagram?) How do you know?
- What is the diagram intended to illustrate? Is the diagram showing a process, sequence, structure vs. function (organization), categories, classification (such as a list or table), or cause and effect?
Finally, as a whole group we discuss the following main idea or concept : "What do you notice about the STR's of both parents and their children?"
To conclude this portion of our lesson, students view an excerpt from the History Channel video "Finding the Romanovs". In a brief, whole group discussion students are asked the following questions:
- "What are the facts in this case?
- Based on the video, how did genetic testing help solve this case?"
"In what way is DNA fingerprinting like actual fingerprinting and how is it different?" Students are given the opportunity to hear from Alec Jefferys, the geneticist who developed techniques for DNA fingerprinting and DNA profiling, in a pre-recorded address via the website DNA Interactive at www.dnai.org. Dr. Jefferys explains how he coined the phrase "DNA Fingerprinting" after a friend compared his novel DNA Technologies to characteristics possessed by traditional fingerprints. Students answer the questions found on Page 3 of the Mystery of the Romanovs Student Lesson Guide as they view the video.
Using student-owned Smartphones or laptops from a reserved laptop cart, students explore the DNA Interactive website for at least ONE additional resource on the topic of DNA fingerprinting and share that resource with the members of their small group. At the end of this portion of the lesson, students should be able to compare what they discover about DNA fingerprinting to what they already know about traditional fingerprinting as a core forensic science technique.
In this portion of the lesson students return to the graphic reviewed during the warm-up activity and take a more focused approach in their evaluation of the graphic. First, in pairs and then as a whole group, we determine the origin of each daughter's genotype based on the genotype of their parents Tsarina Alexandra and Tsar Nicholas II. Students record what they discover on Page 2 of the Mystery of the Romanovs Student Lesson Guide.
STR analysis refers to 'short tandem repeat' analysis and is used quite frequently for forensic science applications. On such application especially useful is for human identification and establishing relationships between individuals since our STR's are inheritable traits passed down from parent to offspring in the form of genes. At the end of this activity students are asked to explain their understanding of this illustration in regards to the principles or "rules" of human inheritance.
For example, in the case of Daughter 1, at the second location (STR 2) in the human genome that was analyzed, she inherited a DNA sequence with 8 short tandem repeats from her mother and a sequence with 10 short tandem repeats from her father. If the DNA of Daughter 1 was extracted, genes of interest isolated and run on a gel, they would create a unique "fingerprint" based on the difference in their size. These unique differences could be compared to the "fingerprints" of the parent in order to establish paternity.
The Romanov Czar was removed from the throne in 1917 and he and his entire family disappeared from prison a year later. Their bodies weren't found until May 1979 in a mass grave. Using the techniques of DNA fingerprinting and DNA profiling, questions surrounding the mysterious disappearance of this Russian royal family were finally answered. Biotechnology helped solve the mystery of the Century!
In our simulation of the process of DNA fingerprinting, in teams students use popbeads to create DNA Sequence Models and then "run" them on a gel to determine if Tsar Nicholas II's remains are among those recovered. The simulation is conducted as a pre-lab to performing an actual DNA analysis and exposes students to the terminology/language, methodology (such as the creation of restriction fragments), potential obstacles a biotechnologist may encounter and an analysis of mock results. A complete overview of this portion of the lesson can be found on Slide 14 thru 18 of the Mystery of the Romanovs Lesson Presentation as well as student data tables to record their findings on Page 4 of the Mystery of the Romanovs Student Lesson Guide.
This real-world example of the use of biotechnology is certainly a student favorite and hopefully the experience will become one of your students favorites as well!
This lesson was inspired in part by materials found in the NeoSci kit entitled, "Genes and Family" in additon to activities located in the BIOZONE Microbiology and Biotechnology modular workbook series!
To simulate gel electrophoresis of the DNA sequences the students create, students use "molecular scissors" known as restriction enzymes to cut the DNA recovered from the remains of the bodies in the mass grave at locations called restriction sites. Students are asked to arrange the resulting Popbead DNA Restriction Fragments on a gel electrophoresis template as they would predict would be seen on an actual gel. The gel should illustrate the banding pattern of DNA samples taken from the bones of the four skeletons identified as a mother and three daughters (provided) and the Male identified as Tsar Nicolas II.
In order to evaluate student learning, students must address the following inquiry: "Based on your data analysis, does one of the four male skeletons belong to the father of these girls? If so, which one? Explain the reasoning behind your answer."
At the conclusion of this lesson, student can additionally be given the opportunity to demonstrate what they have learned by completing a timed writing prompt detailed in the next lesson, EBWR - Recovering the Romanovs.