Ms. Strohfeldt did not omit anything when she designed this comprehensive lesson plan on DNA mutation and sex-linked traits. Begin with a pretest as an anticipatory set. Read a case history of the Clark family and the occurrence of hemophilia in the family. Biologists perform a simulation of a gel electrophoresis for each member of the family and explore DNA sequences. You will find detailed teacher's notes, worksheets with answer keys, and resource links to help you teach this lesson.