Featured in PASCO’s Advanced Biology through Inquiry Teacher Guide
This manual features 22 challenging, standards-based, inquiry lab activities for AP, IB, and honors programs.
Students use pedigree analysis and DNA analysis (electrophoresis) to confirm or refute the initial diagnosis of MELAS for two patients.
Students use pedigree analysis and DNA analysis to confirm or refute the initial diagnosis of MELAS for two patients. MELAS and certain other genetic mitochondrial disorders are unusual in their inheritance: the mutation is passed along maternally only. This maternal inheritance, combined with the complexity in symptoms associated with the disorder, provides a case study that requires students to think critically and evaluate multiple lines of evidence.
The two investigations, “Pedigree Investigation” and “DNA Investigation,” both relate to the same two patients. Either investigation can be performed first or students can complete the investigations simultaneously. Based on the length of your class periods, your students' prior knowledge, and your own pedagogical preference, you can determine how best to organize the investigations. In addition to the time required for the investigations, allow time for a discussion of the background information regarding the mitochondrial genome and MELAS. (Photocopy the supplement at the end of this document for students.)
This experiment may require software and an interface for data collection.