Introduction: Why is this lesson constructivist?
One 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.
Many lesson plans require students to understand concepts, but do not always ask students to apply what they have learned. Constructivism emphasizes the utilization of knowledge gained to interpret other situations. This aids in understanding concepts as well as in retaining ideas. This activity provides some basic information on DNA fingerprinting and how it is used. Importantly, it shows an example of an analysis and asks students to use their new understandings to interpret other similar situations.
Nothing is better for true understanding than hands-on experience. When students "do" something, as opposed to hearing about it or watching a demonstration, they truly gain first-hand knowledge that cannot be obtained in any other fashion. Constructivism emphasizes the process of doing, including designing and interpretation. This activity provides students with a chance to experience for themselves the methods required to do DNA fingerprinting. Working with the equipment and the material provides a deeper understanding of the process. Performance and analysis requires sophisticated thinking, bringing together theoretical aspects (What is a DNA fingerprint and how is it analyzed?) as well as practical issues (What steps must we take to obtain a fingerprint and how can human error affect the results?).
The term "fingerprinting" is used to indicate that each individual can be identified by the unique pattern that exists on the fingers of that individual. No two people have identical patterns. This is also true of an individual's DNA. No two people have the same DNA. Researchers can isolate DNA from an individual and create a "fingerprint" of that individual. These techniques can also be used to determine if an individual carries a defective gene that may cause or predispose the individual to a genetic disease.
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?
- If a genetic disease were carried in your family, would you want to be tested for it? Would you want your unborn child tested for it?
- Who should be given access to information gained from DNA fingerprinting?
- 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?
Discuss this topic and these questions with your group. Talk to one of the instructors about your thoughts and any questions you may have. We will ask your group to discuss your topic with the rest of the class today.