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All introductory biology textbooks, and many sophomore-level genetics textbooks as well, describe several classic experiments in molecular biology. This interrupted case study takes students through two of these classic experiments, namely, those by Griffith and Avery, McCarty and MacLeod that showed DNA to be the genetic material in Streptococcus pneumoniae, and the experiment by Meselson and Stahl that demonstrated DNA replication to be semiconservative. Engaging students with the experiments in a more exploratory manner can reinforce the nature of scientific discovery and the logic behind these findings. The case, which has been formatted as two separate exercises that can be used independently, was developed for use in introductory biology classes for biology majors. The material is accessible enough to also be useful for non-majors college biology or high school AP biology students.

Paul Andersen explains the two major portions of the molecular biology lab in AP Biology. He starts by discussing the process of transformation. He explains how you can use the pGLO plasmid to produce glowing E. coli bacteria. He then describes how you can use restriction enzymes and the process of gel electrophoresis to cut and separate DNA.

This dilemma/decision case study is intended to demonstrate how knowledge of signal transduction pathways can be applied to the pharmaceutical industry and within a medical setting. The case scenario revolves around a physician scientist's analysis of a chronic myelogenous leukemia (CML) patient's resistance to the cancer drug Gleevec® (imatinib). Students explore the molecular targets of drugs that inhibit cell signaling, while considering the best course of treatment for the medical patient. Written for an undergraduate sophomore level cell biology course, the case is also suitable for general biology, genetics, molecular biology, pharmacology, and cancer biology.

This case study was developed to teach the topic of human ABO blood type and genetic inheritance in biology courses at the lower undergraduate level or upper high school level. It is suitable for entry level biology, genetics, and physiology courses. The case narrative tells the story of Kevin, a teenager who is puzzled by the fact that neither of his parents can donate blood to him. He and his best friend ask their biology teacher for help, and she explains human ABO blood types at the molecular and genetic level to solve the mystery. The case consists of three sections, which can be used sequentially or separately. After completing the case study, students will understand the molecular basis of ABO blood types and how genes control the phenotype and genotype of an individual. They will also have a better understanding of how human ABO blood type is inherited from generation to generation.

Before the discovery of insulin in 1921, being diagnosed with Type 1 diabetes was a death sentence. Despite the successful management of diabetes with purified animal insulin, potentially severe side effects were abundant, and alternative ways to produce insulin were needed. This case study guides students through the history of using insulin to treat diabetes, focusing on the development of recombinant DNA technology and the world's first bioengineered drug, recombinant human insulin, which is now used worldwide to treat diabetes. Through the course of this case, students consider the central dogma of molecular biology, the development of recombinant DNA technology, drug design, the importance of recombinant proteins to our society, and the ethical analysis and debates that occur as a result of some scientific discoveries. This case was developed as an introduction to an upper-division biotechnology course focusing on recombinant protein design and production, but could also be used in molecular biology, biochemistry, or introductory biology courses to highlight recombinant DNA and biotechnology.

This flipped case study explores how the topics of membrane structure, transport, and signaling via membrane-bound receptors are intimately associated with the paralysis of muscle targeted by botulinum neurotoxin. The case scenario revolves around a fictitious socialite that has requested the assistance of her personal concierge physician with a condition that has developed after having participated in a Hamptons Botox party. The physician and a shadowing pre-med undergraduate chat about the molecular mechanisms behind Botox induced muscle paralysis. The case is designed as an engaging capstone exercise for students to gain appreciation for how knowledge of basic cellular and molecular biology mechanisms are essential for pharmaceutical development and medical patient diagnosis and prognosis. Written for an undergraduate general biology course, the case is also suitable for use in courses such as cellular biology, neurobiology, or human physiology.

The protagonist of this two-day flipped case study, "Maria," has two problems. She doesn't like it when the apple slices in her lunch turn brown, and she needs to find a project for her biology class that includes molecular biology, preferably one that incorporates plants. Students are enlisted to help Maria understand Arctic Apples™, which don't turn brown because they have been genetically modified to suppress the expression of polyphenol oxidase via RNAi. The case also explores the health, environmental, and safety aspects of growing and eating plants that have been genetically modified to use RNAi. The case applies the central dogma of biology to the creation of genetically modified foods and RNAi and includes a discussion of whether genetically modified foods should be labeled. Several videos are included with the case, including one created by the author specifically for the case. The case is appropriate for use in an introductory level biology or survey level biochemistry course.

DNA to Darwin allows 16-19 year-old school students to explore the molecular evidence for evolution through practical bioinformatics activities that use data analysis tools and molecular data. Each of the activities on this web site centres around an engaging story from recent research in molecular genetics encompassing microbiology, plant and animal biology and human evolution.

This case study examines the molecular methods that were used to reverse engineer the 1918 influenza virus strain in order to try and solve the mystery of why it was so deadly. The story starts in the 1950s with the unsuccessful attempts to culture the influenza virus and follows scientists through to the turn of the century when cutting edge molecular tools enabled scientists to finally resurrect the 1918 virus through reverse genetics. The history and methods involved in resurrecting this deadly virus are reviewed in class with a PowerPoint presentation containing clicker questions (answered with a personal response system) and discussion questions (answered in small groups). This "clicker case" is suitable for high school biology and lower division undergraduate biology classes for non-majors. It could also be used in any lower division non-major class focused on human disease and the history of human disease.

This directed case study examines the molecular basis of cystic fibrosis to emphasize the relationship between the genetic code stored in a DNA sequence and the encoded protein's structure and function. Cystic fibrosis is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein that functions to help maintain salt and water balance along the surface of the lung and gastrointestinal tract. This case introduces students to "Maggie," who has just been diagnosed with cystic fibrosis. The students must identify the mutation causing Maggie's disease by transcribing and translating a portion of the wildtype and mutated CFTR gene. Students then compare the three-dimensional structures of the resulting proteins to better understand the effect a single amino acid mutation can have on the overall shape of a protein. Students also review the concepts of tonicity and osmosis to examine how the defective CFTR protein leads to an increase in the viscosity of mucus in cystic fibrosis patients. This case was developed for use in an introductory college-level biology course but could also be adapted for use in an upper-level cell or molecular biology course.

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In this laboratory you will use some basic tools of molecular biology to gain an understanding of some of the principles and techniques of genetic engineering. In the first part of the lab, you will use antibiotic-resistance plasmids to transform Escherichia coli. In the second part, you will use gel electrophoresis to separate fragments of DNA for further analysis.

In molecular biology, ligation refers to the joining of two DNA fragments through the formation of a phosphodiester bond. An enzyme known as a ligase catalyzes the ligation reaction. In the cell, ligases repair single and double strand breaks that occur during DNA replication. In the laboratory, DNA ligase is used during molecular cloning to join DNA fragments of inserts with vectors - carrier DNA molecules that will replicate target fragments in host organisms.

NIH web portion of lessons on cell and molecular biology

Adverse life experiences, particularly those in childhood, contribute to disease morbidity and mortality [1, 2, 3, 4, 5, 6, 7]. There is considerable interest in understanding the mechanisms through which they do so, as it remains unclear how illness becomes apparent decades after the presumed initiating event. Long-standing hypotheses include chronic activation of the hypothalamic-pituitary-adrenal axis [8, 9, 10] and alterations of neuroimmune function [11]. Molecular signatures of stressful life experiences and their relation to disease are therefore of special interest to clarify the causal relationship between signature, disease, and stress.

Focusing on this species of fruit fly, he and the other researchers in the lab of molecular biologist Sean B. Carroll, had made a prolonged assault on one of the key questions in evolutionary biology: how nature endows creatures with their colorful patterns, from a leopard's dark spots to a butterfly's bold swirls. In different species the patterns serve to attract mates, provide camouflage or provide other advantages in the struggle to survive. But what causes the colors to fall so precisely into place?

This case study is based on the 2014 Ebola epidemic that spread to multiple highly populated countries in West Africa, making it the largest and most devastating outbreak in the history of the virus. The storyline, inspired by a compilation of factual information, unfolds through a fictional narrative wherein students play the role of an infectious disease specialist in training to learn about the techniques used in the detection, diagnosis, and management of Ebola virus outbreaks. The story is presented as an interrupted "clicker case" that combines problem-based case teaching methods with simulated biological laboratory inquiry through the use of Case It, a free molecular biology software, along with the NCBI's online bioinformatics tools and databases. Students work in groups to collaboratively explore various biological and social aspects of this infectious disease outbreak. This case was developed for senior students at the secondary level and can be modified for use in an introductory biology, microbiology, or epidemiology course at the undergraduate level.

This flipped case was designed to introduce students in a general introductory biology course to basic protein structure. The two videos and interrupted case use keratins in hair as model proteins. From the videos students learn how amino acids regulate protein structure, and how small changes in amino acid sequence have large impacts on overall protein organization and function. The case story focuses on a puppy whose hair changes from straight to curly when it sheds its coat. The protagonist tests the adult versus puppy hair, and discovers that the amino acid composition is different in the curly versus straight hair samples. Students apply basic principles of protein structure to hypothesize why the dog's coat switched from straight to curly. The case intentionally stops short of providing a complete answer to the mystery, so students think through the molecular processes logically rather than having a final "correct" answer. An optional activity is provided that makes the case more appropriate for an introductory cell biology class.

This case study synthesizes students' knowledge of the central dogma and cell structure by examining a rare health disorder in order to understand protein targeting and its medical consequences. Students first identify the molecular alteration in affected members of a family with renal Fanconi syndrome as reported in the New England Journal of Medicine (2014). Students then use an online bioinformatics tool to analyze the wildtype and mutant proteins and examine their subcellular localization. Finally, students use this information to explain the symptoms of affected family members. The case is delivered with a PowerPoint presentation that includes a selection of brainstorming prompts and "clicker questions." Students complete a worksheet (included in the teaching notes) before class, making the activity suitable for a flipped classroom. A second worksheet (also included in the teaching notes) is completed during class. The case is written for an introductory biology course for majors, but could also be used as a unit capstone in a non-majors human biology course; the case is also scalable to upper division courses in physiology that specifically explore kidney function.

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.