Osmosis contributes to a range of biological phenomena, from functioning of nephrons in animals to stomatal opening and closing in plants; yet, scientifically simple ideas about osmosis are common. These ideas limit learners’ comprehension of biological processes involving osmosis. They limit, too, science graduates’ potential to contribute to the ecosystem of innovation, which has turned to osmosis for desalinating water and harvesting “blue energy,” for example. To deepen conceptual understanding of osmosis, this ~50-minute lesson asks students to analyze tabulated data, a graph, and photomicrographs related to osmolality of personal lubricants and then to formulate a scientific recommendation for the bulk procurement of personal lubricants. The lesson takes inspiration from an expert review panel convened by the World Health Organization to generate such a recommendation. The lesson includes at its start a consideration of diffusion. This inclusion allows a contrast between osmosis and diffusion to be drawn. The inclusion also deepens students’ understanding of stochastic processes in biology. We have used the lesson in an introductory undergraduate biology course and an upper-level one. Quantitative assessment data were collected from the latter and documented students’ adoption of scientifically rigorous views of osmosis and diffusion. Qualitative data collected from both courses revealed that students found the lesson personally relevant and its information surprising. Students were struck by the apparent inattention to women’s physiology in the design of lubricant. This surprise suggests ways to extend the lesson, for example, into the nature of science, in particular, into the social and cultural embeddedness of science.

Primary Image: Trajectories of three diffusing mastic particles overlying “Diver and Two Octopi.” “Diver and Two Octopi” comes from Kinoe no komatsu, volume 3 (Katsushika Hokusai [Japan, 1760–1849], 1814. Woodblock print. British Museum, asset number 583055001; © The Trustees of the British Museum, who permit use of image under terms of CC BY-NC-SA 4.0). Trajectories (in white) adapted from Figure 6 of “Mouvement Brownien et Réalité Moléculaire” (J. Perrin, Annales de chimie et de physique: tome XVIII. Paris: Gauthier-Villars, 1909. Source: gallica.bnf.fr / Bibliothèque nationale de France).

Fragile X Syndrome is an X-linked genetic disorder resulting from the impairment of transcription of the FMR1 gene, producing less to no FMRP protein. FMRP is a translational inhibitor that plays a key role in neurological development. Recent research has contributed to a more accurate understanding of the heredity, diagnosis, treatment, and molecular impact of both the pre- and full mutation of Fragile X Syndrome. Fragile X Syndrome is unique compared to other genetic disorders typically covered during undergraduate biology courses due to the complex heredity, the molecular changes in the non-coding region of the gene, and the varying phenotypes presented. This review provides insight into the current understanding of Fragile X Syndrome to assist instructors and students using the Fragile States case study or faculty looking to introduce this complex genetic disorder as a way to engage students with the different aspects of biology. Students will be able to explore the complexities of diagnosis due to the disorder’s range of symptoms. Students can also investigate epigenetic gene regulation, specifically how methylation affects the transcription of FMR1. The resulting lack of FMRP has been shown to promote neurotoxicity, and students can investigate how this arises due to the disruption of sphingosine metabolism.

Primary Image: The enzyme DNMT1 interacts with DNA, as produced by enzymlogic.com. Used under license CC BY-SA 2.0 DEED.