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This two-minute video provides brief background on the use of zebrafish as a model in studying animal development, before showing a time-lapse sequence of a fertilized zebrafish egg developing into a larva.  The video includes some annotations that help orient the viewer during the time-lapse sequence.  Teachers might want to mute the narration beginning at 0:42 min to avoid giving students too much information.  This phenomenon could stimulate the following driving questions: How does the zebrafish develop from one cell to the many cells that make up the larva? How do the zebrafish cells divide? How are the developing zebrafish cells similar and different from each other? If all cells in the zebrafish develop from the same original cell, then how do some cells develop differently than others? How are cell division and growth related? 

2:18 Human embryonic development depends on stem cells. During the course of development, cells divide, migrate, and specialize. Early in development, a group of cells called the inner cell mass (ICM) forms. These cells are able to produce all the tissues of the body. Later in development, during gastrulation, the three germ layers form, and most cells become more restricted in the types of cells that they can produce.

This 5 lesson unit, which was designed by teachers in conjunction with scientists, ethicists, and curriculum developers, explores the scientific and ethical issues involved in stem cell research. The unit begins with an exploration of planaria as a model organism for stem cell research. Next, students identify stages in the development of human embryos and compare the types and potency of stem cells. Students learn about a variety of techniques used for obtaining stem cells and the scientific and ethical implications of those techniques. While exploring the ethics of stem cell research, students will develop an awareness of the many shades of gray that exist among positions of stakeholders in the debate. Students will be provided an opportunity to become familiar with policies and regulations for stem cell research that are currently in place in the United States, the issues regarding private and public funding, and the implications for treatment of disease and advancement of scientific knowledge. The unit culminates with students developing a position on embryonic stem cell research through the use of a Decision-Making Framework. Two culminating assessments are offered: In the individual assessment, students write a letter to the President or the President's Bioethics Committee describing their position and recommendations; In the group assessment, students develop a proposal for NIH funding to research treatment for a chosen disease using either embryonic or 'adult' stem cells.

This page shows some key events of human development during the embryonic period of the first eight weeks (weeks 1 - 8) following fertilization. This period is also considered the organogenic period, when most organs within the embryo have begun to form. There are links to more detailed descriptions which can be viewed in a week by week format, by the Carnegie stages or integrated into a Timeline of human development. Online resources available include: individual images of all Carnegie stages, scanning electron micrographs of the earlier stages, cross-sections showing internal structures at mid- and late-embryonic, 3D reconstructions of internal structures, animations of processes, ultrasound scans and information about abnormalites of development.

This case study was written for an introductory course for biology majors who are first learning about embryonic development. The case is composed of several parts and involves a storyline about a team of researchers who find frogs and eggs in bamboo plants during a field study. Students consider what these observations mean, learn basics about the stages of animal embryonic development, and make connections to phylogeny and natural selection. Students then apply their understanding of animal embryonic stage development to the chemical atrazine in the environment by examining data from several experiments. As a concluding activity students write a letter to an agency or newspaper of their choosing stating their opinion surrounding the use of atrazine in the environment. The case proceeds in a progressive disclosure format and involves a combination of class discussion, small group work, and homework. Because the case focuses on very basic animal embryonic development, it would also be a great start to a developmental biology course or an embryology course.

The early stages of embryonic development shape our cells and tissues for life. It is during this time that our newly formed cells are transformed into heart, skin, nerve or other cell types. Scientists are finding that this process is largely controlled not by the genome, but by the epigenome, chemical markers on DNA that tell cells when to turn genes on and off. Now, studying zebrafish embryos, researchers at Washington University School of Medicine in St. Louis have shown that the epigenome plays a significant part in guiding development in the first 24 hours after fertilization.

Most 12-year-olds love playing videogames -- Thomas Suarez taught himself how to create them. After developing iPhone apps like "Bustin Jeiber," a whack-a-mole game, he is now using his skills to help other kids become developers. (Filmed at TEDxManhattanBeach.)

Parkinson's is a result of the loss of cells in various parts of the brain, including one portion that produces the neurotransmitter dopamine. Dopamine is essential for being able to move in a coordinated way, so the loss of dopamine causes the tremors often associated with the condition. While the exact cause of Parkinson's is unknown, genetics and environment are contributing factors. Most cases occur in patients with no family history of Parkinson's disease, but there are 13 gene mutations that have been linked to either causing the disease or increasing one's risk of developing it. Certainly not everyone who carries these gene mutations develops Parkinson's, but identifying these genetic indicators is the beginning of developing more precise treatments.

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 tells the story of Joyce, a biology student who notices the development of some unusual symptoms (foot slapping and slurred speech) in her mother. In an effort to understand the cause, Joyce views a documentary-style trigger video (created by the case author) that suggests to Joyce that her mom may in fact have amyotrophic lateral sclerosis or ALS. The rest of the case walks Joyce through understanding how normal neurons compare to neurons in ALS patients and how that might affect muscle function. The case explores the link between genes, particularly SOD-1, to the formation of malformed proteins and its potential role in the development of ALS. The case concludes with a discussion of drug development and highlights the timeline and costs associated with drug discovery as Joyce becomes concerned about the lack of drugs in the pipeline for ALS, which her mother is ultimately diagnosed with. The case is appropriate for a number of classes including general biology, biotechnology, anatomy and physiology, upper level-cell biology, or any human health and disease-related course.

The most recent human retroviral infections leading to germ line integration took place with a subgroup of human endogenous retroviruses called HERVK(HML-2). The human genome contains ~90 copies of these viral genomes, which might have infected human ancestors as recently as 200,000 years ago. HERVs do not produce infectious virus: not only is the viral genome silenced - no mRNAs are produced - but they are littered with lethal mutations that have accumulated over time. A recent study revealed that HERVK mRNAs are produced during normal human embryogenesis. Viral RNAs were detected beginning at the 8-cell stage, through epiblast cells in preimplantation embryos, until formation of embryonic stem cells (illustrated). At this point the production of HERVK mRNA ceases. Viral capsid protein was detected in blastocysts, and electron microscopy revealed the presence of virus-like particles similar to those found in reconstructed HERVK particles. These results indicate that retroviral proteins and particles are present during human development, up until implantation.

Scientists at the University of California, San Diego School of Medicine have found that mutations that cause autism in children are connected to a pathway that regulates brain development.

University of Washington Institute for Science and Mathematics Education has created partnerships to envision, cultivate, and study equity-focused educational models and practices in areas of science, technology, engineering, and mathematics (STEM). We do this work across the K-12 grade span and across formal and informal learning environments. We believe that all young people should be able to decide their own futures. Their opportunity to learn in STEM fields plays a critical role in their opportunity to do so now and in the future. We develop innovative projects that seek to deliver on this goal and closely study them to develop knowledge about how to broaden participation in STEM. The Institute is strongly affiliated with the Learning in Informal and Formal Environments (LIFE) Center.

In this case study students are provided with information for piecing together the story of how forest fragmentation and biodiversity loss can affect the risk of Lyme disease transmission to humans. The case introduces the dilution effect, a widely accepted theory-and one of the most important ideas in disease ecology-which suggests that disease risk for humans decreases as the diversity of species in an area increases. It also explains how landscape fragmentation, one of the most common threats to biodiversity, can influence the risk of Lyme disease for humans. Students interpret and discuss various figures to develop a concept map that connects all the individual results of the story. Students gain an appreciation for the complexity of species interactions in an ecosystem, the effects of forest fragmentation on these interactions and the possible consequences for human health. This activity was developed for an undergraduate introduction to environmental sciences course under the topic of biodiversity and conservation, but would also be suitable for interdisciplinary studies interested in examining the connections between conservation and public health.

This case study explores the recent (2010 - 2016) outbreak of neural tube defects, specifically anencephaly, in a rural three-county region of Washington state, particularly Yakima, WA. The case study focuses on the biological aspects of teratogens that may cause birth defects as well as epidemiological investigations of disease outbreaks. By the end of the case, students will have explored how our environment may have severe biological consequences on the human body during pregnancy and will have evaluated governmental and scientific investigations of a rare outbreak of birth defects. This clicker case study was developed for a non-majors biology course entitled "Human Development: Conception to Birth," although it could be taught in any introductory biology course for majors or non-majors during a unit on human reproductive biology or developmental biology. The case assumes that students have no prior knowledge of developmental biology or birth defects. The case study could also be adapted for upper-division courses by getting more in-depth on the specifics of teratogen mechanisms, the developmental biology and physiology of neural tube defects, or more complex epidemiological analyses.

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.

It's one of the big mysteries of cell biology. Why do mitochondria-the oval-shaped structures that power our cells-have their own DNA, and why have they kept it when the cell itself has plenty of its own genetic material? A new study may have found an answer. Scientists think that mitochondria were once independent single-celled organisms until, more than a billion years ago, they were swallowed by larger cells. Instead of being digested, they settled down and developed a mutually beneficial relationship developed with their hosts that eventually enabled the rise of more complex life, like today's plants and animals.

This interrupted case study introduces basic modeling to investigate a decline in an American marten population on an island in Southeast Alaska. Two summer field technicians working on a long-term field ecology project for one of their professors notice that there are fewer marten captures this year. Through discussions with their professor, conversations with a local fur trapper, and based on their own observations, they develop a plan to model the population and the potential causes of the decline to solve the mystery. Students use Excel or other database software along with life tables and introductory population ecology to investigate three potential causes of the marten population decline. This case was developed for use in an environmental science or wildlife management course but could also be used in an advanced science high school course or general ecology course. It would be beneficial for students to have some background in statistics including how to interpret R-squared values, p-values, and 95% confidence intervals.

This case study was developed to teach students the importance of understanding the behavior of wildlife, explore the difficulty in making management decisions when the public is invested in a species, and to help students develop critical thinking and public speaking skills. Students learn about the conservation status and behavior of the black rhinoceros by reading a primary literature article and answering a series of questions. They then listen to a Radiolab podcast that explores the moral dilemma of whether it is ethically appropriate to shoot an endangered rhinoceros if the purpose is to raise conservation funds. Students are assigned one of five positions and write essays to prepare for a town hall style debate in which they examine the pros and cons of such a decision. The Radiolab podcast is based on real events, and is also representative of many ethical dilemmas that wildlife managers regularly face. This case study is appropriate for several upper division biology courses.

In this case, developed for an introductory genetics class, students meet a woman whose family has a history of colon cancer. Students create a pedigree based on information from the case and discuss what it means to be genetically predisposed to cancer. Using bioinformatics tools from the NCBI database, students identify and examine the mutation in the woman's APC gene that results in genetic predisposition to colon cancer. Finally, they investigate the biological function of the APC protein to understand why this mutation contributes to the development of cancer and determine whether APC is a proto-oncogene, tumor suppressor gene, or genome stability gene.