Meiosis is well known for being a sticky topic that appears repeatedly in biology curricula. We observe that a typical undergraduate biology major cannot correctly identify haploid and diploid cells or explain how and why chromosomes pair before segregation. We published an interactive modeling lesson with socks to represent chromosomes and demonstrated that it could improve student understanding of ploidy (1). Here we present an improvement on that lesson, using DNA paper strips in place of socks to better demonstrate how and why crossing over facilitates proper segregation. During the lesson, student volunteers act out the roles of chromosomes while the whole class discusses key aspects of the steps. Strips of paper with DNA sequences are used to demonstrate the degrees of similarity between sister chromatids and homologous chromosomes and to prompt students to realize how and why homologous pairing must occur before cell division. We include an activity on Holliday Junctions that can be used during the main lesson, skipped, or taught as a stand-alone lesson.

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Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.

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Thomas H. Gosnell School of Life Sciences (COS)


RIT – Main Campus