This is one of 25 assessment probes from the book,” Uncovering Student Ideas in Science, Volume 2: 25 More Formative Assessment Probes”, by Page Keeley and co-authors. All assessment probes in this collection are aligned to a particular science concept and field-tested by several teachers in classes of diverse student backgrounds. The purpose of this assessment probe is to elicit students’ ideas about inheritance of genetic traits. The probe is designed to reveal the ideas students have about how traits, in this case fur color, are passed on to offspring. The resource can be used to engage students in the topic or to assess their understanding along the way. The probe can be used at the beginning of a unit on inheritance and sexual reproduction.