Karyotype Analysis Activity

This classroom activity is based on a constructivist learning design and engages students in physically constructing a karyotype of three mock patients. Students then diagnose the chromosomal aneuploidy based on the karyotype, list the symptoms associated with the disorder, and discuss the implications of the diagnosis. This activity is targeted at undergraduates in a nonmajors genetics course, but the goals align with AP Biology Big Idea 3 and Next Generation Science Standards HS-LS3. The activity illustrates the relationship between genotype and phenotype, reinforces the chromosome theory of inheritance, and includes mapping of meiotic nondisjunction events.

William Bateson and the chromosome theory of heredity: a reappraisal

William Bateson vigorously objected to the assumptions within the chromosome theory of heredity proposed by T. H. Morgan because he perceived inadequate experimental data that could substantiate the theory. Those objections were largely resolved by 1921, and Bateson reluctantly accepted the basic assumption that chromosomes carried the genetic factors from one generation to the next. Bateson's own research at that time on developmental genetics seemed out of touch with the general tone of the genetics field, and the chromosome theory did not provide illuminating mechanisms that elucidated phenomena such as plant variegations or chimeras. Bateson imagined a general theory of heredity and development based on vortices and waves, concepts he borrowed from contemporary physics. For decades he sought to devise an intellectually and aesthetically satisfying theory to eventually explain evolution in genetic terms, but his aspirations remained unfulfilled when he died in 1926.