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When an elementary school teacher calls in sick to work, she finds out that she is not the only one who will be missing school that day.  Children from her fifth grade class have also become ill and parents are calling to report the absences. The concerned principal of the school finds out the fifth grade class had a field trip to one of the local parks the day before. The case shows the areas visited by the class and provides discussion between the principal and a physician that teaches the readers about water quality and EPA standards for bacteria levels in recreational water. The case has an optional lab component that provides the theory for three methods that can be used to conduct microbial water analyses.  Procedures are included for teachers to lead a lab activity to test water to identify which location in the park caused the illness. This case study and accompanying laboratory activity are recommended for an environmental engineering course or a lower level science course.

For years whale evolution was characterized by speculation and limited evidence. Evolution critics even focused on whales as a means to criticize evolutionary theory. Now whale evolution represents one of the best examples of "macroevolution." This "clicker case" uses this fascinating story of historical irony as a backdrop to the study of whale evolution. First, students study an array of whale fossils to learn how evolution is properly viewed as a branching, relationship-based process, not a linear, progressive, "chain-of-being." Using this view they learn how scientists seek to reconstruct past relationships and study transitional features, not search for "missing links." Students then learn that evidence for macroevolution relies on several lines of independent evidence from fossils, comparative anatomy, embryology, genetics, and paleoecology. With a focus on macroevolution, this case makes a critical contribution to evolution education. It could work well in a lower level undergraduate biology / evolution / paleontology course (non-majors or majors), or in an upper-level evolution course, perhaps early in the semester as a primer for related topics.

Federal regulators on Thursday approved a genetically engineered salmon as fit for consumption, making it the first genetically altered animal to be cleared for American supermarkets and dinner tables. The approval by the Food and Drug Administration caps a long struggle for AquaBounty Technologies, a small company that first approached the F.D.A. about approval in the 1990s. The agency made its initial determination that the fish would be safe to eat and for the environment more than five years ago.

This interrupted case study addresses several concepts related to climate change and its effect on the American pika. Often called an indicator species for climate change, the pika has a unique set of variables specific to its environment. Factors such as temperature, snowpack, and vegetation can affect the distribution and ultimately the chances of survival. The case was designed for use in a "flipped" classroom in which students prepare in advance outside of class by filling out a worksheet while watching a video. The video, created by the author of the case, provides students with baseline information that they apply in class to come up with key ideas and predictions, followed by analysis of actual data to test the hypotheses they develop. The case study incorporates group discussion, analysis of experimental design, and data evaluation as central activities and can be taught in a single 50 minute class session. The case was designed for use in a large introductory-level class, but is also appropriate for smaller classes.

This flipped clicker case study explores the fascinating relationship between the Arizona Bark Scorpion (the most venomous scorpion in North America) and the Southern Grasshopper Mouse. Initially it would seem that the grasshopper mouse is no match for the scorpion's venom; however, the grasshopper mouse is easily able to eat the scorpion and is largely immune to the scorpion's sting. By working through this case study, students learn about neuron anatomy and physiology as they explore how the grasshopper mouse is able to survive the scorpion's venom. This case study was developed for an introductory biology course for majors, but it could also be used in an introductory biology course for non-majors or in an anatomy and physiology course. The case requires that students learn basic neuron anatomy and action potential physiology prior to class by reading their textbook or by watching videos on the subjects. An optional set of guided questions tailored to Campbell Biology (10th ed.) is included in the teaching notes.

In this clicker case study for a flipped classroom, students familiar with the stages of meiosis work in small groups to determine the predicted genetic makeup of the parthenogenetic offspring of a Komodo dragon, based on four different types of parthenogenesis. Students then learn about the actual genetic makeup of the offspring and determine how meiosis was modified to allow parthenogenesis in this fascinating lizard. The sex of the offspring is explained, based on ZW/ZZ sex determination. A video specifically made for this case prepares students for the in-class activities, which are guided by a PowerPoint presentation. The case also examines how facultative parthogenesis may be adaptive in Komodo dragons and the implications of facultative parthogenesis to conservation of these vulnerable lizards. The case was developed for a general biology class, but could also be used in an introductory course on conservation or cell biology.

This case study explores the topics of diffusion, osmosis, membrane transport, and the physiological significance of glucose and insulin in the human body. The story begins with a high school athlete, Timmy, who is incredibly efficient at metabolizing carbohydrates for energy; this is where the reader is introduced to normal carbohydrate digestion and metabolism for energy within skeletal muscle cells. As Timmy enters college, he withdraws from sports and physical activity but continues to consume massive amounts of highly soluble carbohydrates, resulting in insulin resistance and ultimately type II diabetes. Throughout the case students are prompted with conceptual questions and interactive figures that require the application and transfer of information they have been introduced to. Originally written for intermediate and advanced physiology courses that cover foundational and complex concepts in science, the case is also appropriate for courses in intermediate biology, nutritional sciences, animal sciences, and exercise sciences.

This case study teaches students about allopatric speciation through an investigation of the benthic and limnetic sticklebacks of Paxton Lake, which are among the youngest species on Earth, diverging from each other after the Pleistocene glaciers melted and the Gulf Islands formed. Researchers at the University of British Columbia have carried out a variety of fascinating studies on these hardy little fish. Results from this research (formatted as data sheets included in the teaching notes) are provided to students who design experiments and then compare actual data to investigate why benthic and limnetic sticklebacks seldom interbreed in Paxton Lake. Developed for a first-year biology course for majors organized around the general theme of evolution and the history of life on Earth, this case study is an updated version of another case in the collection, "Something's Fishy in Paxton Lake" (Sharp, 2001). The current version is especially suited for a flipped classroom in which students prepare for class ahead of time with a reading assignment that also involves the viewing of a video by the case authors that introduces the mechanisms of allopatric speciation.

This interrupted case study examines basic concepts of chemical bonding by telling the story of "Madison," a young girl eager to learn how her hair can transition from natural curls to straight, smooth tresses. The case can be used to teach or review the major categories of bonds (ionic, covalent and hydrogen), major macromolecules of life, and hydrolytic and dehydration reactions. It also explores how chemical relaxers and heat through blow drying and flat-ironing can change the nature of straight, wavy and curly hair through the disruption of protein shape. Students will thus learn what it means when a protein has become denatured and how various variables such as pH, heat and salts can lead to the unraveling of the three-dimensional shape of proteins. This case is suitable for an AP high school course, or for an introductory biology or chemistry course for majors or non-majors. This activity can also be used as a review of basic biology and chemistry for students in an upper-level biochemistry course.

This interrupted case study for the flipped classroom applies evolutionary genetics research to human health. Students learn about a naturally occurring, but rare, allele of the CCR5 gene, CCR5-Δ32, which provides resistance to HIV. They use data from primary literature sources to predict and interpret worldwide patterns of CCR5-Δ32 frequency distribution. They then discuss how these allele frequency patterns may have been driven by selection imposed by various diseases or by other evolutionary mechanisms. Next, they test published data using Hardy-Weinberg equilibrium to examine if CCR5-Δ32 also provides genetic resistance to West Nile virus. Finally, they complete a jigsaw discussion of Nature News articles that report on how CCR5 research is being used to develop therapies to treat HIV. Originally written for the evolution portion of a yearlong biology series for undergraduate majors, the case is also appropriate for some non-majors biology courses or, with added complexity, upper-level evolution, genetics, or cell biology courses.

This interrupted case study for the flipped classroom introduces the human microbiome from the perspective of one of its occupants, Heidi Helicobacter (Helicobacter pylori).  Heidi lives in the gut of Kristen, a college student, and discusses her fellow microbial inhabitants, functions of these various microbes, and alludes to factors that can disrupt the healthy human microbiome. Students prepare for class by viewing several brief videos and then discuss in class whether Kristen should undergo a fecal microbiota transplant to treat her Clostridium difficile infection.  A lab component has students model, using colored beads, how antibiotics can act as a selective agent for drug-resistant microbes such as C. difficile. The case concludes with Kristen about to give birth to a new baby several years later.  Students listen in as Kristen's microbes discuss the formation of the new baby's microbiome. The case has been used successfully in a general biology class and could easily be adapted for a microbiology, human physiology, ecology, or evolution course.

A common misconception is that Darwin suggested that something as complex as the eye could not have evolved through natural selection. While the misunderstanding often comes from an incomplete reading of his argument, we have long known that intermediate varieties of eyes (e.g., eyespots, cupped eyes, and complex camera-type eyes) exist in a variety of organisms. Eyes are so common that it was thought that they had evolved independently 40-60 times. More recent molecular work, however, has identified the role of Pax6 genes and their homologs in the formation of eyes during development. The basic information for eye formation appears to have been present in the common ancestor to all bilaterans, and perhaps may be more ancient than that. This interrupted case study examines the history of evidence for eye evolution from Darwin's initial postulates, through evidence of multiple intermediate forms, concluding in an examination of Pax6 homologs. The case is primarily for an introductory biology class but an additional section would be appropriate for upper-level evolution or developmental biology courses.

This clicker case was designed to teach students about basic enzyme structure, mechanisms of enzyme inhibition, and mechanisms of drug resistance. The story follows Oliver Casey, a patient afflicted with Chronic Myelogenous Leukemia (CML). CML is caused by a chromosomal mutation that affects the tyrosine kinase ABL, an enzyme important in regulating cell growth and proliferation. The chromosomal mutation gives rise to the BCR-ABL fusion gene that produces a constitutively active ABL kinase, which causes the leukemia. In May 2001, the Food and Drug Administration approved the use of a rationally designed tyrosine kinase inhibitor, imatinib (Gleevec®), for the treatment of CML. During that same month, Gleevec made the cover of TIME magazine, described as "new ammunition in the war on cancer." The case is structured for a flipped classroom environment in which students view preparatory videos (including one by the author) on their own before beginning the case. Written for a first-year introductory biology course, the case could also be adapted for AP/Honors high school biology or a cancer biology course.

This directed case study was developed to introduce students to the CRISPR-Cas9 system for genome editing. CRISPR-Cas9 has made numerous headlines in both the scientific and popular press, and thus serves as an excellent model for learning current biotechnology and applying concepts from biology courses. After providing a general overview of CRISPR-Cas9, the majority of the case focuses on the clinical applications of the system as experienced by a carrier for the X-linked recessive allele underlying Duchenne Muscular Dystrophy. The case is structured so that students use a variety of popular and scientific sources (some of which may require a subscription to access-check with your institution), increasing in difficulty as they move through each part of the case. The goals are for students to learn the molecular mechanisms of CRISPR-Cas9, the benefits and limitations of the system, and the clinical applications of the technology. Open-ended questions are included to spark discussion of ethical considerations, societal impacts, and the overall implications of the technology.

This case study challenges students to differentiate between anecdotal evidence and science-based evidence related to human health. The case uses a "flipped" approach in which students watch two preparatory videos prior to attending class. The first video defines anecdotal evidence while the second characterizes the different categories of scientific studies that generate evidence that is not anecdotal. Students watch the videos, analyze scenarios for anecdotal evidence, and think about what types of evidence they use to make health-related decisions. When students meet in class, they work in groups to compare and contrast these different categories of scientific studies and classify actual research studies aided by a dichotomous key for distinguishing between different types of studies related to human health. Primarily designed for students in introductory general biology courses, the activity could also be useful for lower division nutrition, physiology, or non-major biology courses or any course where students need to differentiate between science and pseudoscience.

It is now well known that non-native species have the potential to be harmful to an ecosystem, but that wasn't always the case, and getting rid of non-native invasive species is usually a difficult task. This brief, interrupted case study tells the story of kudzu's introduction into the United States in the late 1800s. It also examines (and even questions) how we define words like "native" versus "non-native" and "invasive" versus "non-invasive." Students will learn how invasive species impact ecosystems and why some non-native species never become established. They also will address questions related to eradicating non-native invasive species. For example, is it okay to attempt to get rid of a non-native species with another non-native species? As part of the activity, students also will have to decide whether or not kudzu should be considered "native" since it has been in the United States since 1876. Originally designed for a general biology course for majors, the case has also been used in a biology class for non-majors as well as an environmental biology class.

This directed case study was developed in order to present genomic data to students, allow them to interpret the impact of genetic variations on phenotype, and to explore precision medicine. Students are introduced to "Josie," a college sophomore who decides to have her genome sequenced after learning about genome-wide association studies (GWAS) in class. As students work  through the case, they learn about the different technologies that can be used in GWAS studies and interpret Josie's results for a subset of genetic markers that affect a range of traits from pharmacogenetics to disease risk alleles and non-pathogenic traits. Students are confronted with ethical issues such as duty to inform, actionable results, and variants of unknown significance (VUS). Students are also asked to reflect on their feelings about getting genomic testing for themselves. An optional activity for advanced students (included in the teaching notes) involves using the Gene database at NCBI to explore variants of the CYP2C9 gene. The case study is appropriate for use in undergraduate genetics or molecular biology classrooms.

To understand the importance of elements to nutrition. Of the approximately 115 elements known, only the 19 highlighted in purple in Figure 1.26 are absolutely required in the human diet. These elements-called essential elements-are restricted to the first four rows of the periodic table (see Chapter 32 "Appendix H: Periodic Table of Elements"), with only two or three exceptions (molybdenum, iodine, and possibly tin in the fifth row). Some other elements are essential for specific organisms. For example, boron is required for the growth of certain plants, bromine is widely distributed in marine organisms, and tungsten is necessary for some microorganisms.

Free tools for teaching - printable worksheets, classroom printables and on-line worksheet templates with images from Tools for Educators. Use these free worksheets to print, game makers, and programs for teachers  to make and print teaching resources with pictures or classroom materials for kids. 

This case study was developed for an introductory biology course with the goal of integrating content (specifically, structure/function, signaling pathways, and homeostasis) while reinforcing general critical thinking skills and the scientific method (generating hypotheses, evaluating evidence, and making predictions). The case is suitable for a flipped classroom and there are several videos associated with it. The case revolves around an obese two-and-a-half-year-old boy who won't stop eating. Students become familiar with some basic concepts related to obesity and leptin signaling through the videos that they watch before class. They then use class time to work through the case (delivered as an interactive slide show, including several clicker questions) to determine the genetic basis for this child's obesity and possible therapies to manage his weight. The case could also be adapted and expanded to be used in a physiology course to explore the interaction of various hormones that regulate appetite and metabolic rate or in a cell biology class to explore JAK-STAT signaling.