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This flipped case study is formatted as a PowerPoint presentation that uses group experimentation to encourage active learning in a large science classroom. There are options for using either wet bench experimentation or an online simulation, depending on the class goals. Students learn about plant transpiration and how it affects normal plant processes (photosynthesis). The basics of transpiration are covered in an animated video viewed outside of class. The experiment and/or simulation of transpiration can be conducted in or out of class. If the class is very large, the instructor may choose to assign the experiment/simulation for outside of class (post-video) and have the students bring their data to class, or the instructor may choose to just present the students with a data set from which they can work with their groups in class. At the end, students should be able to define transpiration, explain climate effects on transpiration rates, and how transpiration rates affect the overall physiology of the plant itself, through their own hypothesis design and experimentation.

This case study takes place at a fictional biotechnology company developing herbicides against invasive plant species. The case study focuses on five herbicides with different effects on photosynthesis. Students play the role of lab interns and explore photosynthesis and the herbicide effects by engaging in concept mapping, experimental design, data manipulation, and data analysis. The goal is to use the experimental data to predict the steps in photosynthesis that are inhibited by each herbicide. Students should come away from the case study with a process-based understanding of photosynthesis. This case study is designed for the "flipped" classroom with suggested preparatory videos and associated assessment questions included. Videos can be supplemented with textbook readings or mini-lectures. This activity was developed for a non-majors introductory biology course but it could also be used in any general biology course, including majors' courses. It might also be used to establish foundational knowledge for more advanced discussions of photosynthesis in plant biology (botany) courses.

This clicker case addresses several important concepts related to evolution. First, it explores artificial selection and selective breeding. Charles Darwin used artificial selection as an example to support his Theory of Evolution by Natural Selection. Belyaev's Fox-Farm experiment is used as an example of a study that used selective breeding as the primary experimental procedure to investigate changes in a lineage. Second, it addresses an interesting observation made by Charles Darwin in The Origin of Species in which he noted how domesticated species also show interesting traits such as drooping ears which seem to be common in domesticated species. The "Farm-Fox Experiment" not only demonstrates how a research team can thoroughly investigate an intriguing question, but also serves as a classic example of elegant experimental design. Designed for use in a large introductory-level biology class, this case study would also be appropriate for smaller classes as well as for upper-level evolution courses.

This feature explores some of the therapies using adult stem cells, and looks at some of the experimental stem cell therapies that are going on today.

This set of mini cases on the ecology of eastern cottontail rabbits is designed to give students practical experience using statistics in a scientific context. Given a dataset and experimental design, groups of students are asked to play the part of a wildlife management researcher to determine the results for each study. Students practice the scientific process and gain experience making hypotheses and predictions, choosing an appropriate statistical test, interpreting and displaying results, and presenting data to others. Students choose between four basic, commonly used, statistical tests (t-test, one-way ANOVA, linear regression, and Chi-square test), and justify their choices. This activity was developed for undergraduate level students and is applicable to biology courses, particularly those dealing with ecology or management. The case is designed for student groups, but could be modified into clicker questions or individual assignments.

Why is the North American population of monarch butterflies declining? In 1999, a study published in the journal Nature suggested that a variety of genetically modified corn was killing these iconic butterflies. While it was later shown that the conditions in this study did not mirror those in the field, the results garnered a lot of media attention and many people today still believe that monarchs are being killed by GMOs. This case familiarizes students with the plight of the monarchs, encourages them to think about how to test the hypothesis that a toxin is responsible for their decline, and takes a critical look at several studies that investigated the role of Bt corn in the life cycle of monarchs. This interrupted case takes 60-90 min to complete, requires little to no science background, and can be used to explore the ecology and wildlife management of monarchs; risk assessment, toxicity, and exposure; experimental design, the scientific method, hypothesis, and critical thinking; or the relationship between science, the media and the public.

Despite clinical and experimental evidence implicating the intestinal microbiota in a number of brain disorders, its impact on Alzheimer's disease is not known.

2 min video clip showing experimental process

Normally, male squirrel monkeys can't distinguish between red and green hues-they're what is called color-blind in humans. The South American Saimiri genus lacks a gene that allows color-sensitive cells in the eye, called cones, to differentiate red and green from gray. To these animals, other colors, such as blue, brown and orange, appear faded. But Sam was one of two males in the experimental group of a groundbreaking 2009 ophthalmological study conducted at the Washington National Primate Research Center in Seattle. Husband-and-wife vision researchers Jay and Maureen Neitz injected a viral vector behind the retinas, the part of the eye that responds to color, of Sam and his simian lab partner, Dalton. The virus contained the genetic code in human eyes for red pigment, giving the monkeys an extra class of cone photoreceptor.

The number of new Ebola cases is tapering off, but the search for new treatments continues. Now, one research team has found potential drug candidates that successfully treated up to 90 percent of mice exposed to the Ebola virus. They report their findings in the journal ACS Infectious Diseases.

Transgenic organisms, which contain DNA that is inserted experimentally, are used to study many biological processes. In this lab, you will create a transgenic fly to study circadian rhythms.

The Virtual Biology Lab Project is designed to provide interactive activities that demonstrate ecological principles. We provide agent-based models that simulate classic ecological experiments or concepts across a wide range of ecological topics. Students manipulate experimental parameters and observe the results. These results are provided numerically and graphically and are reinforced with a visualization of the model's "world". The content is suitable for advanced high-school and college students.

A decade-old technique that allows researchers to control brain function in lab animals could partially restore sight to the blind. In a trial sponsored by RetroSense Therapeutics, a startup company in Ann Arbor, Michigan, doctors will inject a harmless virus loaded with DNA from photoreceptive algae into the eyes of 15 patients suffering from retinitis pigmentosa. The experimental procedure represents the first human test of optogenetics, which is a technique that genetically modifies neurons to make them responsive to light. Doctors from the Retina Foundation of the Southwest will perform the procedure, and attempt to transfer the job duties of photoreceptor cells to different cells in the eye to restore sight.

Research has revealed striking differences in the trillions of bacteria - a.k.a., the microbiome - in the intestines of children with and without autism. But the gut bacteria in individuals with autism aren't just different. Researchers at the California Institute of Technology have shown for the first time that they may actually contribute to the disorder. They reported in the journal Cell in December 2013 that an experimental probiotic therapy alleviated autism-like behaviors in mice and are already planning a clinical trial.

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 case study provides an overview of the seminal experimental work that led to the discovery of DNA structure and the confirmation of the semi-conservative model of DNA replication. By guiding students through a chronological series of historic experiments and discussing some of the collaborations and controversies involved in the original research, students learn about the history and nature of science in addition to several important biological concepts. A number of recommended videos, including one created by the author, enable instructors to use the "flipped-classroom" mode of instruction according to which students read primary literature and watch videos on their own before group discussions and activities. The case study was developed for use in an introductory undergraduate biology course, and would also be appropriate for use in a high school biology course. Some prior knowledge or instruction may be required, depending on the level and learning objectives of the course.

"Reading and understanding scientific literature can be a daunting task for students in introductory science courses. This decision/dilemma case study helps ease them into the process by using a short scientific article with a simple experimental design that compares two types of ACL (anterior cruciate ligament) surgery, autograft and allograft. The case tells the story of Todd, a martial artist who recently tore his ACL in competition. With the help of the article, Todd discusses the potential surgical options provided by his doctor with his friend, Sam, a medical student. The case has the added value of demonstrating how one can use scientific literature to make informed healthcare decisions based on clinical evidence. Please note that the required article (Kane et al., Knee Surgery, Sports Traumatology, Arthroscopy 24(11): 3627-33) is not provided with this case; prior to assigning this material, instructors should confirm that students can access the article, since access may vary by institution."

This case study introduces students to the "Red Queen Hypothesis." The hypothesis states that when two species compete for a limited resource or exist in a predator-prey relationship, in order for the antagonists to remain in relative population equilibrium, there must be ongoing and reciprocal adaptation on each side. If one species fails to adapt, it may quickly face extinction. Students are introduced to the Red Queen Hypothesis through an excerpt from Lewis Carroll's novel, Through the Looking Glass, in which Alice meets the Red Queen. They then review experiments from the research literature to evaluate the validity of the hypothesis in extant populations.  Students culminate their learning by contrasting their knowledge of the Red Queen Hypothesis to Darwinian evolutionary theory based on a passage from On the Origin of Species.  Students then craft a letter to Darwin helping to explain his "wedge" theory, a notion he originally developed but removed from later iterations of his book due to a lack of experimental evidence. Originally developed for advanced high school biology students, the case also may be used in a college-level introductory course on evolutionary biology.

This clicker case addresses several concepts related to the evolutionary ecology of herbivore defenses. A survey of several different studies that investigated chemical defenses in Thymus vulgaris (thyme) gives students the opportunity to develop hypotheses, pose potential experiments, and interpret data to develop a better understanding of not only herbivore deterrence, but also how natural selection can involve different pressures selecting for different phenotypes. The case study incorporates group discussion, analysis of experimental design, and data evaluation as central activities. It can be taught in a single 50-minute class session, an economy that is achieved in part by using a "flipped" approach. Students prepare outside of class by watching several short videos (one of which was made by the author) that teach the basics of herbivore deterrence and abiotic and biotic forces in the environment that can influence plant adaptations. The case study was designed for use in a large introductory-level class, but would also be appropriate for smaller classes or upper-level evolution courses.

This case study centers on symbiotic relationships between insects and bacteria using Drosophila melanogaster, the common fruit fly, and the recently discovered bacterial species Sodalis praecaptivus. Until recently, the only known Sodalis species of bacteria were symbiotically associated with several different species of insects. However, free-living non-symbiont Sodalis species are being tested in several different insect species to determine if they can transition into symbiotic relationships. A pre-class assignment (see Supplemental Materials) directs students to read an open access research journal article providing a comprehensive review of S. praecaptivus and describing an experimental weevil model that parallels that of the fruit fly. A PowerPoint presentation shown in class (see Supplemental Materials) provides further background before students work in small groups to complete the case study focusing on results from D. melanogaster and S. praecaptivus model experiments.  Although developed for a genetics course, this interrupted case is appropriate for an upper-level biology course. It can be completed within a 75-minute class meeting, or adapted for shorter time periods.