Genetics - Where's the Cat?

Where's the Cat?

Teacher: Ellen Shepherd Mayo
Subject: DNA fingerprinting, forensic application
Grade Level(s): 7 10 12
Target Audience: any biology
Materials Needed: photocopies of DNA template, scissors, tape, craft magnet strips
Class Time: 1 to 3 class periods
Brief Summary: Using paper DNA sequences, the class tries to find the answer to a paternity problem. After a woman was raped, she finds herself pregnant and wants to know whether the father is her husband or the suspected rapist. The paper DNA is cut, run on a gel, and probed, all in simulation. Students can see how restriction enzymes, gel electrophoresis, and probe hybridization work.
Student Objective(s): Students learn the basic results of restriction enzymes, gel electrophoresis, and probe hybridization. Students will explain how a DNA profile may be used in forensic identification. Students explain how alleles are inherited in Mendelian fashion.
Description of Activities: 1.) Students first assemble DNA strips representing a standard, the mother, the husband, the suspect, and the baby. 2.) These paper strips are then "cut", using the HaeII recognition sites. 3.) The fragments are assembled on a "gel" on the wall, according to size. 4.) The fragments are "probed" for the sequence CAT, which has been prepared by placing a small piece of craft magnet behind each CAT location. The "probes" are GTA sequences on bright paper, with magnet pieces attached. 5.) After probing, all "unprobed" sequences are removed. The remaining sequences represent an autoradiograph, and paternity can be deduced.
Further Information and References: Co-authored by Ellen Mayo and Anthony Bertino
>

This site complies with the HONcode standard for trustworthy health information:
verify here.