Group items tagged

X-Spin Viral RNA Extraction Kit provides a fast an easy isolation method for the extraction and purification of nucleic acid (RNA) in samples. We are top RNA extraction kit manufacturer and offer viral rna extraction kits or rna Isolation kit covering many sample types and throughput needs.

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. 

The anole lizards of the Caribbean islands represent a group of about 150 closely related species, most of which evolved within the past 50 million years from a single colonizing species. Different processes, including geographic isolation, adaptation to different environments, and reproductive isolation, play a role in anole speciation. 

Explore speciation with The Amoeba Sisters. This video discusses sympatric and allopatric speciation and covers several types of isolation types including behavioral, temporal, and habitat isolations.

When scientists first made contact with an isolated village of Yanomami hunter-gatherers in the remote mountains of the Amazon jungle of Venezuela in 2009, they marveled at the chance to study the health of people who had never been exposed to Western medicine or diets. But much to their surprise, these Yanomami's gut bacteria have already evolved a diverse array of antibiotic-resistance genes, according to a new study, even though these mountain people had never ingested antibiotics or animals raised with drugs. The find suggests that microbes have long evolved the capability to fight toxins, including antibiotics, and that preventing drug resistance may be harder than scientists thought.

A complete understanding of evolution requires knowledge that spans many biological sub-disciplines. However, students are often taught evolution in the context of ecological systems and isolated from genetic and cellular ones. To address this issue, we have developed case studies that track the evolution of traits from their origination in DNA mutation, to the production of different proteins, to the fixation of alternate macroscopic phenotypes in reproductively isolated populations.

Gene flow is the transfer of genetic material between separate populations. Many organisms are divided into separate populations that have restricted contact with each other, possibly leading to reproductive isolation. Many things can fragment a species into a collection of isolated populations. For example, a treacherous mountain pass may cut off one herd of mountain goats from another. In human beings, cultural differences as well as geographic separation maintain unique populations: It is more likely that a person will marry and have children with someone who lives nearby and speaks the same language.

This directed case study in PowerPoint format focusses on the London Underground Mosquito, Culex molestus, and its potential relationship to the common mosquito, Culex pipiens, in order to explore the topics of evolution, reproductive isolation, and speciation. As the story unfolds, the case mirrors the process of science. The students receive some initial data and observations collected by Byrne and Nichols in London. Based on these observations, the students then form a hypothesis and design an experiment. Finally, they receive more data collected by Becker et al. and draw conclusions.

The virtual lab includes four modules that investigate different concepts in evolutionary biology, including adaptation, convergent evolution, phylogenetic analysis, reproductive isolation, and speciation. Each module involves data collection, calculations, analysis and answering questions. The "Educators" tab includes lists of key concepts and learning objectives and detailed suggestions for incorporating the lab in your instruction.

Dubilier is hardly alone in her plight. A heaping teaspoon of soil or a shot of ocean water may contain as many as one million bacterial species. Many of them are potential gold mines of chemicals and metabolites with medicinal, engineering, and energy applications. But when researchers have tried to culture these microbes in the lab, only a minority of cells form colonies. Clearly, nutrients, a carbon source, and time are usually not enough to coax bacteria isolated from the wild to grow in a laboratory setting. So what's the missing ingredient?

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.

To address this issue, we have developed case studies that track the evolution of traits from their origination in DNA mutation, to the production of different proteins, to the fixation of alternate macroscopic phenotypes in reproductively isolated populations.

GMOs are organisms that have had their DNA modified through genetic engineering. This is often done by taking a gene from one organism and putting it into another one to alter it in a desirable way. For example, when genetic engineers want to create a corn crop that is resistant to pests, they seek out the trait in Bacillus thuringiensis (Bt) soil bacteria that naturally acts as a pesticide. From there, engineers isolate the gene responsible for that trait and directly insert it into the corn's DNA. This corn is then bred with other corn until it's ready to be produced for consumption.

The researchers isolated different subpopulations of human brain stem cells and precisely identified, which genes are active in which cell type. In doing so, they noticed the gene ARHGAP11B: it is only found in humans and in our closest relatives, the Neanderthals and Denisova-Humans, but not in chimpanzees. This gene manages to trigger brain stem cells to form a bigger pool of stem cells. In that way, during brain development more neurons can arise and the cerebrum can expand. The cerebrum is responsible for cognitive functions like speaking and thinking.

Evolutionary biologists have developed many techniques to analyze how male and female mating preferences have co-evolved. These studies combine animal behavior, sensory biology, phylogenetics, and neurobiology to observe the effects of male trait biases based on female receiver systems; that is, the "attractiveness" of the male trait to potential female mating partners.

array of HS science lesson from non-profit Science Pioneers in Kansas City, MO

tutorial