Group items tagged

The origin of viruses remains mysterious because of their diverse and patchy molecular and functional makeup. Although numerous hypotheses have attempted to explain viral origins, none is backed by substantive data. We take full advantage of the wealth of available protein structural and functional data to explore the evolution of the proteomic makeup of thousands of cells and viruses. Despite the extremely reduced nature of viral proteomes, we established an ancient origin of the "viral supergroup" and the existence of widespread episodes of horizontal transfer of genetic information. Viruses harboring different replicon types and infecting distantly related hosts shared many metabolic and informational protein structural domains of ancient origin that were also widespread in cellular proteomes. Phylogenomic analysis uncovered a universal tree of life and revealed that modern viruses reduced from multiple ancient cells that harbored segmented RNA genomes and coexisted with the ancestors of modern cells. The model for the origin and evolution of viruses and cells is backed by strong genomic and structural evidence and can be reconciled with existing models of viral evolution if one considers viruses to have originated from ancient cells and not from modern counterparts.

This interactive explores different anatomical features of the human body and what they reveal about the evolutionary history we share with other organisms, including earlier, long-extinct species.

Polar bears are an iconic symbol of climate change, but regionally relevant examples of susceptible biota are needed to highlight how global forces impact local environments. In this interrupted case study, students follow a young naturalist as she explores why saltmarsh sparrows are increasingly rare in coastal wetlands of the northeastern United States. In small groups, students diagram how sea-level rise may alter saltmarsh sparrow habitat and analyze a graph to determine if there is evidence to support sea-level rise. The social implications of rising sea levels induced by climate change can also be explored with an optional jigsaw activity. Students who successfully complete this case study will integrate key concepts related to sea level rise, interpret scientific data and draw conclusions about environmental change, and evaluate alternative management decisions. Originally developed for an undergraduate ecology course, the case could easily be adapted by college or high school instructors for an introductory biology or an environmental science course.

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.

This interdisciplinary case study uses the format of a progressive disclosure to explore certain advances in biotechnology and evaluate them within the framework of societal needs, concerns and pressures.  When faced with a heart valve transplant, a high school student and her mother must decide between multiple approaches, some current and others emergent. Highlighted in this case study are the topics of xenotransplantation, 3D bioprinting and the mature minor rule. The case includes a role-playing, public hearing activity that can be used to explore many aspects at the interface of technology and culture: religious rights, parental rights, public health care policy and safety, animal rights, economic issues of organ marketing, and psychological issues of body image.  This case study was originally designed for first year collegiate classes (introduction to biology, introduction to psychology) but is also applicable to AP high school. The flexible nature of the case also allows for expansion of several aspects for advanced classes across multiple disciplines.

Activity A Better Fire!! Activity Advanced Fire Activity Directable Fire!! Activity Fire!! Activity Life Activity Life Lite Activity Spread of Disease Discussion about Agent Modeling Discussion about Chaos Discussion about Chaos is Everywhere Worksheet Emerging Patterns Worksheet Worksheet Emerging Patterns Worksheet (doc) Worksheet Rabbits and Wolves Exploration Questions Worksheet Rabbits and Wolves Exploration Questions (doc)  

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.

In this activity, students analyze scientific figures to understand principles of island biogeography theory that determine the number of species in an isolated habitat. This activity uses a jigsaw approach to explore the processes that determine the equilibrium number of species in a habitat and how they are affected by both area and isolation. Two "Student Handouts" are provided as options for the activity. The "Analyzing Graphical Data" handout engages students in graph interpretation and sensemaking from data. The "Building the Equilibrium Model" handout facilitates a scaffolded investigation of the dynamic equilibrium model of island biogeography; students construct immigration and extinction curves to demonstrate the effects of area and isolation on the equilibrium number of species. 

Students can manipulate mutations in bunnies, such as fur color and teeth length. By altering the environmental factors, students can see how the bunny populations change over time. For example, in a warm environment, more bunnies will have brown fur, but in the cold environment, more bunnies will have white fur. The student worksheet includes instructions on how the simulator works. Then students perform a variety of "experiments" to explore mutations in the populations. I include this as part of a unit on evolution, so students are familiar with VIDA charts. Students complete a chart at the end of the activity to summarize how variations in populations lead to adaptation.

Have you heard of Alexander von Humboldt? Not likely. The geologist turned South American explorer was a bit of an 18th century super scientist, traveling over 24,000 miles to understand the relationship between nature and habitat. George Mehler details Humboldt's major accomplishments and why we should care about them today.

This interrupted case study explores the role of cytoskeletal structures on human health, specifically on respiratory function, sperm motility, and female fertility. It follows the story of a couple struggling to conceive a child and the doctors working to help them. Students are presented with clinical histories, narrative elements, documentary-style videos, and microscopic evidence in order to determine the cause of the couple's infertility. Along the way, they learn about the three types of cytoskeletal elements and the roles these play in cellular biology and human physiology. The use of videos makes it suitable for the "flipped classroom," allowing students to prepare outside the classroom for the case study, which they then complete in class. An original video by the author on the structure and function of microtubules, microfilaments, and intermediate filaments is included. The case was developed for an introductory level general biology course and could be delivered during a unit on the cell structure and function. The case could also be used in a cell biology course.

BodyMaps is an interactive visual search tool that allows users to explore the human body in 3-D. With easy-to-use navigation, users can search multiple layers of the human anatomy, view systems and organs down to their smallest parts, and understand in detail how the human body works. Using detailed 3-D models of body parts-including muscles, veins, bones, and organs-BodyMaps offers a new way to visualize and manage your health. See how the coronary artery delivers blood to the heart, and learn how plaque build-up on artery walls leads to heart disease. Locate the exact location of a pulled muscle or broken bone, and find information on how to prevent injuries. View a cross-section of the human brain, and learn which areas control certain emotions and body functions. By offering rich, detailed anatomical images alongside links to relevant and useful health information, BodyMaps allows you to leam about your body and your health in a personalized and revolutionary new way.

Shape of Life is a series of FREE short classroom videos that beautifully illustrate the evolution of the animal kingdom on planet earth. Based upon an original PBS Series, Shape of Life is especially designed for students and teachers who want a first-hand account of how animals adapt and thrive. The series is NGSS aligned with exquisite focus on diversity, biodiversity, adaptability, body structure, design, behaviors, and the innovative scientists who explore these creatures.

Shape of Life is a series of FREE short classroom videos that beautifully illustrate the evolution of the animal kingdom on planet earth. Based upon an original PBS Series, Shape of Life is especially designed for students and teachers who want a first-hand account of how animals adapt and thrive. The series is NGSS aligned with exquisite focus on diversity, biodiversity, adaptability, body structure, design, behaviors, and the innovative scientists who explore these creatures.

American Museum of Natural History Explore the natural world with Science Bulletins; our documentary Feature Stories, Data Visualizations, and News updates focus on recent discoveries and new technologies in astrophysics, Earth science, biodiversity, and human health and evolution.

Project Noah is a tool to explore and document wildlife and a platform to harness the power of citizen scientists everywhere.

Students begin by watching the online video clip and completing a worksheet. After that assignment, instructors can decide which of the two activities (or both!) to use in class. In Activity 1, students identify the locations on chromosomes of genes involved in cancer, using a set of 139 "Cancer Gene Cards" and associated posters. In Activity 2, students explore the genetic basis of cancer by examining cards that list genetic mutations found in the DNA of actual cancer patients. Small-group work spurs discussion about the genes that are mutated in different types of cancers and the cellular processes that the affected genes control. The Activity 1 and 2 Overview document provides short summaries of the two activities along with key concepts and learning objectives, background information, references and rubrics, and answers to students' questions. Both cancer discovery activities are appropriate for first-year high school biology (honors or regular), AP and IB Biology. Activity 2 is also appropriate for an undergraduate freshman biology class.

Buckle up for a prokaryote and eukaryote comparison before taking a ride into a cell to explore organelle structures and functions! This cell introduction also includes the modern cell theory.

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 PowerPoint-driven case study follows the progress of three undergraduate students as they attempt to model the rapid spread of an influenza outbreak to determine whether their local newspaper's claim that "40% of the campus has the flu" is accurate. The case introduces epidemiological modeling using a base model for a seasonal influenza outbreak written in the NetLogo programmable modeling environment. In class, students develop tests for the various parameters of the model, run simulations, and evaluate the output. The students then explore the impact of influenza control strategies (vaccination, isolation, and antiviral medications), and finish with the question of whether the continuing outbreak on campus could be a pandemic. The case is written at a basic level for a lower-level undergraduate lecture-style class, but can be adapted to upper-level courses as well. The case was piloted in four different microbiology courses. The simulations stimulated active discussion and the content worked well, whether it was used in a pre-nursing microbiology or upper-level immunology class.

Explore the cycling of carbon among carbon reservoirs! Then discover the importance of nitrogen, essential for amino acids and nucleotides, and learn about the nitrogen cycle! Vocabulary discussed includes ammonification and denitrification.