(M226) CHALLENGING STUDENT MISCONCEPTIONS OF MENDELIAN GENETICS.
Bowen, Jeffery 1, Carson, Michael1, Krevosky, Merideth1, 1 Bridgewater State College, Bridgewater, MA
ABSTRACT- The module Chances Are? is an inquiry-based laboratory module where undergraduate students play the role of genetic counselors studying the inheritance of Sickle Cell Syndrome and has been used in a senior level Mammalian Reproductive Physiology course. Historically, students confuse the rules of Mendelian genetics when applied to an a posteriori situation instead of the usual a priori. For example, students want to utilize the standard 1 homozygous dominant : 2 heterozygotes : 1 homozygous recessive ratio for a standard heterozygous cross in all situations, even if the known offspring is not homozygous recessive. This type of misconception will impact the accuracy of determining the statistical chance of a heritable trait in an unborn child. In Chances Are?, the unborn child comes from a pedigree known to carry Sickle Cell Syndrome and the students need to consult the parents about the probability that the child will be born with the genetically inheritable disease. In this module, students become proficient in Mendelian genetics and protein physiology by analyzing a family history, constructing a medical pedigree, and determining the statistical chance of passing this disease to an unborn child. Students perform polyacrylamide gel electrophoresis on blood samples to detect the presence of abnormal hemoglobin on a family member to help better determine the chance the unborn child will be born with Sickle Cell Syndrome and examine the effect of the testing on the probability. The experiment distinguishes which family members are homozygous dominant, homozygous recessive or heterozygous for the disease. The laboratory experience encourages students to use critical thinking skills and consider social and ethical issues surrounding genetic testing.
KEY WORDS: mendelian genetics, inquiry-based lab, pedigree analysis, sickle cell syndrome