This is the second course in a two-semester sequence on astrophysics. Topics include galactic dynamics, groups and clusters on galaxies, phenomenological cosmology, Newtonian cosmology, Roberston-Walker models, and galaxy formation.
Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.
By the end of this section, you will be able to:Explain Mendel’s law of segregation and independent assortment in terms of genetics and the events of meiosisUse the forked-line method and the probability rules to calculate the probability of genotypes and phenotypes from multiple gene crossesExplain the effect of linkage and recombination on gamete genotypesExplain the phenotypic outcomes of epistatic effects between genes
By the end of this section, you will be able to:Discuss Sutton’s Chromosomal Theory of InheritanceDescribe genetic linkageExplain the process of homologous recombination, or crossing overDescribe how chromosome maps are createdCalculate the distances between three genes on a chromosome using a three-point test cross
This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:
"Left unchecked, excessive CO₂ emissions have the potential to significantly warm the planet in the coming decades. One way to curb this trend is to develop more efficient power electronics, which can channel electricity from clean energy sources to the global grid, with minimal energy losses. A new study reports one device that could help make this clean future a reality. Losses in traditional power electronics can be traced to the relatively sluggish movement of the charge carriers that carry current through them. That translates to slow switching speeds and overall inefficient device performance. This new device takes advantage of a phenomenon called bulk conduction, where charge carriers are generated (in this case, with light) and controlled nearly simultaneously throughout the device. Results showed that the device, made from silicon carbide, could perform 6 times faster than existing solid-state devices. That speed improvement alone could help reduce global CO₂ emissions by more than 10%..."
The rest of the transcript, along with a link to the research itself, is available on the resource itself.
Students learn how engineers apply their understanding of DNA to manipulate specific genes to produce desired traits, and how engineers have used this practice to address current problems facing humanity. They learn what genetic engineering means and examples of its applications, as well as moral and ethical problems related to its implementation. Students fill out a flow chart to list the methods to modify genes to create GMOs and example applications of bacteria, plant and animal GMOs.
This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:
"Disruption. For better or worse, perhaps no other buzzword better captures the spectacular pace of technology over the past few decades. Though it’s casually attached to any new app or gadget hatched in the tech world, several examples of true technological disruption surround us today. One of the most compelling is perovskite-based solar cells. With a power conversion efficiency that now tops that of their silicon predecessors, these rapidly developing devices stand to make a meaningful impact on the solar energy market—and energy consumption at large. A perovskite is a compound possessing a crystal structure that looks like this. Some of the best performing perovskite materials used in solar cells feature an organic ion housed within an inorganic cage. This complex structure provides a chemical ruggedness not found in traditional solar cell materials. Economically, that translates to cheaper manufacturing. And in terms of operation, it means more stable performance..."
The rest of the transcript, along with a link to the research itself, is available on the resource itself.
This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:
"The 16S rRNA gene is widely used for bacterial phylogenetics, species delineation, and microbiome research. Historically, researchers assumed that sequence variations in this gene were only due to speciation and inheritance. But there are reports of recombination events and an unreliable phylogenetic signal. To examine this directly, researchers performed four intra-genus analyses and one inter-genus analysis using pathogenic and core human microbiome genera. In all analyses, the 16S rRNA gene was recombinant and subject to horizontal gene transfer. At the intra-genus level, the 16S rRNA gene averaged 50.7% concordance with the species phylogeny, one of the lowest of the core genes. Further analysis found that the single nucleotide polymorphism (SNP) count was a major factor influencing concordance. 690 ± 110 SNPs would be required to reach 80% concordance, but the average SNP count for the 16S rRNA gene was only 254..."
The rest of the transcript, along with a link to the research itself, is available on the resource itself.