Paul Andersen explains how genes are regulated in both prokaryotes and eukaryotes. He begins with a description of the lac and trp operon and how they are used by bacteria in both positive and negative response. He also explains the importance of transcription factors in eukaryotic gene expression.

The word biology means, "the science of life", from the Greek bios, life, and logos, word or knowledge. Therefore, Biology is the science of Living Things. That is why Biology is sometimes known as Life Science.

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BI102A is a survey course that introduces the discipline of molecular biology and genetics, exploring topics including cell division, protein production, inheritance and gene regulation. This book focuses on putting those topics into an appropriate context for students who are not biology majors.

BI101A is a survey course that introduces the discipline of cellular biology, exploring topics including the scientific method, parts of a cell, and how cells function. This book focuses on putting those topics into an appropriate context for students who are not biology majors.

General Biology is intended to leave the student with an integrated view of the living world including the nature of sciences, evolution of biological organization, composition and organization of living substances, metabolism, control, reproduction, heredity and ecological relationships. This class meets the A.A. degree lab science requirement in the State of Washington.Login: guest_oclPassword: ocl

Welcome to the wonderful world of microbiology! Yay! So. What is microbiology? If we break the word down it translates to “the study of small life,” where the small life refers to microorganisms or microbes. But who are the microbes? And how small are they?

Generally microbes can be divided into two categories: the cellular microbes (or organisms) and the acellular microbes (or agents). In the cellular camp we have the bacteria, the archaea, the fungi, and the protists (a bit of a grab bag composed of algae, protozoa, slime molds, and water molds). Cellular microbes can be either unicellular, where one cell is the entire organism, or multicellular, where hundreds, thousands or even billions of cells can make up the entire organism. In the acellular camp we have the viruses and other infectious agents, such as prions and viroids.

In this textbook the focus will be on the bacteria and archaea (traditionally known as the “prokaryotes,”) and the viruses and other acellular agents.

Paul Andersen describes genetic drift as a mechanism for evolutionary change. A population genetics simulator is used to show the importance of large population size in neutralizing random change. The near extinction of the northern elephant is used as an example of the bottleneck effect.

Designer babies, the end of diseases, genetically modified humans that never age. Outrageous things that used to be science fiction are suddenly becoming reality. The only thing we know for sure is that things will change irreversibly. The video "Genetic Engineering Will Change Everything Forever - CRISPR" is a resource included in the Genetics and genomics topic made available from the Kurzgesagt open educational resource series.

We have the choice to attack one of our oldest enemies with genetic engineering. But should we do it? The video "Genetic Engineering and Diseases - Gene Drive & Malaria" is a resource included in the Genetics and genomics topic made available from the Kurzgesagt open educational resource series.

Paul Andersen explains how the frequency of recombination between linked genes can be used to determine the relative location of genes on a chromosome.  Thomas Hunt Morgan and Alfred Strutevant used the fruit fly to develop a theory of chromosomal inheritance and discover crossing over.

Find out how the genetic material in the Type A flu virus can get shuffled around to create brand new types of viruses! Rishi is a pediatric infectious disease physician and works at Khan Academy.

Paul Andersen previews the information in the genetics unit. He defines the central dogma of biology and explains how DNA creates an RNA transcript that is used to translate proteins. He differentiates between mitosis and meiosis. He also explains how Mendelian genetics differs from the current understanding of genetics.

Mr. Andersen describes the virtual fly lab. Software at sciencecourseware.org allows for multiple matings and statistical analysis.

Paul Andersen explains how genotypes can be expressed or not based on changes in the environment. He starts with a brief description of the Himalayan rabbit and how melanin production can be disrupted by high temperature. He explains how this could be advantageous in both the arctic fox and hare.

Paul Andersen explains how changes in the genotype of an individual can affect the phenotype. He begins with genotype:phenotype::letters:story analogy. He explains how mutations can be neutral, beneficial or harmful. He also explains how mistakes in the cell cycle can lead to disorder, sterility or new species.

What factors lead to a natural disaster? What causes a famine? Why do cities flood? According to a recent article in The Atlantic, Houston's flooding during the 2017 Hurricane Harvey was primarily caused by impervious pavement which prevents the absorption of water into the land. This example illustrates how nature and society are interlinked, which is the main focus of Geography 30, Penn State's introductory course to nature-society geography. In addition to examining the linkages between human development and natural hazards, this course will also explore human society's connection to food systems, climate change, urbanization and biodiversity. The course will also cover topics of ethics and decision making in order to help students evaluate the tradeoffs of these interconnections.
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Geography 431 is designed to further understanding of the natural processes of aquatic ecosystems, management of water resources, and threats to sustaining water quantity. Develop awareness and appreciation of the perspectives about water as a precious resource, commodity, and sometimes hazard. Learn how and why water is distributed unevenly around the Earth. Examine how resource management decisions are strongly related to water availability, quantity, and quality. The course examines water resources management; dams and dam removal; provision of safe potable water; threats to water quantity and quality; land use changes; the water economy; water laws and policy; institutions for water management at the global, national, regional, and local scale; and issues of water security and climate change.

Geysers and grizzlies and glaciers, oh my. The national parks may be America's best idea, saving the finest parts of the nation for everyone to enjoy forever. What better way to learn about the natural world than to tour the parks with us? We'll explore how the mountains and valleys formed and why they often come with volcanoes and earthquakes. You'll see what really killed the dinosaurs and how we can help save their modern relatives in the parks. With film clips, slide shows, and our geological interpretations of classic rock songs, isn't it time for a road trip?