Introduction
DNA Fingerprinting
DNA is the genetic material that makes you unique. Unless you have an identical twin, your DNA is different from that of every other person in the world. And that’s what makes DNA fingerprinting possible. Experts can use DNA fingerprints for everything from determining a biological mother or father to identifying the suspect of a crime. What, then, is a DNA fingerprint and how is it made? Here, you'll find out by solving a mystery—a crime of sorts. Your job will be to compare this DNA fingerprints to solve mysteries.
Ready? Let's get to work!
Task
Task One:Discuss The Case Studies And Solve Them
ROCK A BYE BABY
Jennifer and Steven Barker had been married for five years. They had a good relationship but they began to drift apart. They decided to get a divorce. Everything was relatively civil, and the assets from the marriage were divided equally between the two. However, there was a disagreement about the car -- a Mercedes Benz purchased after the wedding with joint funds. Both Jennifer and Steven loved the car and neither would give it up. The judge in the case, Judge Tomson, decided Steven would get the car.
Several months after the break up, Jennifer discovered she was pregnant. She claimed Steven was the father and demanded he pay child support. Steven denied he was the father. He claimed Jennifer was just trying to get back at him for keeping the car and refused to pay any support for her baby. The legal battle went on for months, until well after baby Andrew was born. As with the dispute over the car, Judge Tomson again had to settle the case. She ordered DNA fingerprinting done on Jennifer, Steven, and Andrew.
Take a look at the DNA fingerprint analysis.
- M is the mother, Jennifer Barker.
- C is the child, Andrew Barker.
- AF is the alleged father, Steven Barker.
Remember, to conclude that the alleged father is truly the father, every band in the child's fingerprint that does not match in the mother's fingerprint must match in the father's.
Is Steven Barker the father or not?
A FAMILY DISEASE
The Rieser family had a long history of a strange disease. The earliest known case of the disease occurred in Jeb Rieser back in 1765. Originally from a small village in England, he was the first member of the family to come to America. When he was about thirty-five years old, Jeb developed problems walking and coordinating his fine motor movements. He deteriorated rapidly, loosing all muscle movement, and died several years later. He left his widow with five children, none of whom developed the disease.
As the years passed and the family grew larger, many other cases of this strange disease were noted. In 1896, a doctor diagnosed the disease as Jenkins neuromuscular disorder (JND), naming the disease after himself for having discovered it. Dr. Jenkins had no cure and no treatment for the family but he did recommend that no member of the family have children until they were over thirty-five years old to ensure the disease would not spread. Few followed his advice. Most of the Riesers were farmers and needed help with the land. Large families were needed. They could not wait until late in life to have children.
One day in 1989, a descendent of old Jeb, Alex Rieser, was watching TV and heard a news report. It seems that doctors could now do a DNA test to determine if someone could inherit a disease called Huntington disease, which was very similar to JND. Alex was twenty-nine years old and recently married. He very much wanted to start a family but did not want to take a chance of passing on the deadly disease. Alex decided to contact a genetic counselor at the local hospital. The counselor told him there was a chance the disease could be diagnosed with a genetic test. The test would require DNA fingerprints from individuals in the family who had the disease and individuals who were over thirty-five and didn't have the disease. Alex's relatives decided to help.
Below is a picture of DNA fingerprints of eight members of the Rieser family. Individuals 4, 6, and 8 have JND. The other family members do not have the disease. Is there a particular fragment of DNA that is associated with individuals who have the disease? If so, which one is it? Could you determine if Alex Rieser will develop this disease? How?
As it turns out, Jeb Rieser had several brothers and sisters back in England. Some of their descendants also developed this strange disease. Could this test be used to determine if a member of the English side of the family will come down with JND?
Process
Task 2: Creatively Present The Discussion Question To The Class.
[video:https://www.youtube.com/watch?v=vLfjdqinlzQ]
[video:https://www.youtube.com/watch?v=AkBUriMK9u8]
This technology has many applications. Suspects have been convicted, as well as acquitted, of crimes based on evidence found at the scene of the crime, such as a drop of blood. Paternity cases have been argued using this technology: the DNA of the child is compared with that of the possible father to see if the child has any of the same patterns of DNA, indicating a biological relationship. Individuals can also be tested for genetic diseases that run in a family.
There are controversies surrounding this technology. Some argue that the techniques used are not fool proof and therefore they should not be used to convict someone of a crime. Some people worry about who should have access to the information obtained from individuals tested for genetic diseases. For instance, many believe insurance companies would deny coverage for people who are determined to be predisposed to diseases based on information gained from DNA fingerprinting. Other types of discrimination may occur based on this information. For instance, an airline may not hire a pilot if that person was found to have a gene causing a predisposition to high blood pressure. This person may be more likely than most people of having a heart attack, and this would endanger many lives if the person were piloting a plane when and if a heart attack occurred.What are some other possible uses of this technology? What are some other benefits and problems associated with DNA fingerprinting?
- What are some other possible uses of this technology? What are some other benefits and problems associated with DNA fingerprinting?
This could take the form of debate,role play , powerpoint presentation or even a concept map not more than 5 mins.
Evaluation
The following key areas of the curriculum were examined
The transmission of heritable characteristics from one generation to the next involves DNA and genes (ACSSU184)
Scientific understanding, including models and theories, are contestable and are refined over time through a process of review by the scientific community (ACSHE191)
Formulate questions or hypotheses that can be investigated scientifically (ACSIS198)
Plan, select and use appropriate investigationmethods, including field work and laboratory experimentation, to collect reliable data; assess risk and address ethical issues associated with these methods (ACSIS199)
Advances in science and emerging sciences and technologies can significantly affect people’s lives, including generating new career opportunities (ACSHE195)
Conclusion
There are many issues involved in this topic: what further information do you need in order to continue discussing these questions and to make informed decisions about this technology?
Credits
Teacher Page
Tne notion of constructivism stresses that the learner considers multiple aspects of an open-ended situation and identifies what more he or she needs to know in order make decisions and conclusions. This activity presents students with some basic facts about DNA fingerprinting and some controversies surrounding this technology. It then asks students to consider these issues and answer some difficult questions. In addition, the activity stresses relevance, asking students to consider if they would want DNA testing done on them or members of their family. As many new genes are discovered almost on a daily basis, and as news stories are constantly coming to light regarding the use of DNA fingerprinting, current events can easily be incorporated into this lesson. News articles can enhance the activity and provide other situations for consideration.