Water is one of the most common molecules in the universe. Water is polarized, but it has many states besides the normal tetrahedron depicted in standard biology texts. Water is also the most ubiquitous molecule on Earth, the universal solvent. It is the internal and external habitat of cells. Ecologically, water is contiguous with life and the…

The central dogma of molecular biology describes the transfer of genetic information from nucleic acids to proteins and stipulates that the system cannot work in the reverse direction. As a fundamental principle in biology, the dogma is as influential as it is controversial. Some commentators have debated the central dogma's empirical accuracy…

Storytelling can stimulate learning by delivering scientific content within a narrative that increases comprehension and engagement. In this article I describe the coevolutionary arms race between toxic newts and predatory garter snakes. This engaging story centers on the use of a deadly neurotoxin called tetrodotoxin (TTX) as an antipredator…

As researchers, teachers, and practitioners we often encounter young professionals and lay adults who do not understand basics of mammalian body temperature regulation. Often their single solid piece of knowledge is that some vertebrates (mammals and birds) are warm-blooded and some (fish, amphibians, and reptile) are cold-blooded, which is…

Plant Physiology and Ecophysiology (PPE) is a subject taught in the biology degree. One of the skills that students must acquire is "the ability to solve PPE problems." Acquiring this competence requires a precise working methodology, a high degree of presence, and teamwork between teachers and students. Because of the COVID-19 pandemic…

Human rights issues can be topics of conflict, resistance, and indifference; thus, these issues are seldom broached in traditional college STEM courses. In this article, I share process, content, and sources used to introduce college students to the biology of the singularity of race and the biology of sexual identity. One or two class meetings on…

A classroom exercise is described in which college students take part in creating and supporting an evolutionary hypothesis that explains effort grunting. The exercise holds their interest throughout and readies them to understand hypotheses of animal and plant evolution. It informs them about the dependence of cultural evolution upon biological…

Gas diffusion, as a basis for complex biological processes such as respiration, is a core principle for understanding fundamental physiology. Students, however, often find these concepts challenging, in particular when expressed formally as in Fick's law of gas diffusion. This introduction to Fick's law uses the representations of…

A point mutation in the MC1R gene, a G-protein-coupled receptor, has been found that could have led to the formation of two subspecies of Solomon Island flycatcher from a single ancestral population. I discuss the many roles that G-protein-coupled receptors play in vertebrate physiology and how one particular point mutation can have enormous…

A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

Over the past 10 years, college textbooks in human anatomy and physiology have typically presented the events of the ovulatory menstrual cycle in a linear format, with time in days shown on the x-axis, and hormone levels, follicular development, and uterine lining on the y-axis. In addition, the various events are often shown over a 28-day cycle,…

Evolution is widely regarded as biology's unifying theme, yet rates of rejection of evolutionary science remain high. Anecdotal evidence suggests that cognitive dissonance leading to an emotional response is a barrier to learning about and accepting evolution. We explored the hypothesis that students whose worldviews may be inconsistent with the…

In learning genetics, many students misunderstand and misinterpret what "dominance" means. Understanding is easier if students realize that dominance is not a mechanism, but rather a consequence of underlying cellular processes. For example, metabolic pathways are often little affected by changes in enzyme concentration. This means that…

A major challenge in teaching organ development and disease is deconstructing a complex choreography of molecular and cellular changes over time into a linear stepwise process for students. As an entry toward learning developmental concepts, I propose two inexpensive hands-on activities to help facilitate learning of (1) how to identify defects in…

Heart valves play a vital role in efficient circulation of the blood, and the details of their physical structure are related crucially to their function. However, it can be challenging for the learner to make the mental connection between anatomical structures of valves and the changing pressure gradients that the valves experience and come to an…