A Lesson in Genetics

In my honors biology classes, we are studying genetics. To understand the inheritance of human traits, we did an activity that required students to draw a person. As I presented the class with a list of traits and the genes associated with each trait (e.g., ability vs. inability to roll your tongue or hitchhiker's thumb vs. straight thumb), students flipped a coin to determine which trait to express in their drawings. The students flipped their coins twice for each trait, because we have two alleles coding for each individual trait (e.g., two alleles coding for tongue rolling). In order to complete the activity, the students needed to understand the difference between dominant and recessive alleles. At the end, each student had a unique drawing. We learned that due to genetic variation, it is highly unlikely that any two individuals will be exactly alike, and that two individuals who look alike could, in fact, have different genes.