Insects outnumber humans by a lot and we only like to think we're in charge because we're bigger than they are. But insects and other arthropods weren't always so small. About 315 million years ago during the Carboniferous Period, they...

In our final episode of Crash Course Geography we're going to take a look towards the future, and to do that we'll need to revisit our fundamental geography tools: space, place, and human-environment interactions! We'll talk about the...

In the world of chemistry, an "organic" compound is often described as anything with carbon in it, and "organic chemistry" is the study of carbon compounds, but there is actually no single definition of what "organic" means in chemistry,...

This week, Hank elaborates on why Fugu can kill you by illustrating the ideas of solutions and discussing molarity, molality, and mass percent. Also, why polar solvents dissolve polar solutes, and nonpolar solvents dissolve...

In this video Paul Andersen explains how systems can be used to understand phenomenon in science and create better designs in engineering. He starts by defining the characteristics of a system and describes how system models can be used...

We've talked about mixtures and solutions, solutes and solvents, but what about things that can't be undone? What about Chemical Changes? Would it surprise you to know that baking a cake is a Chemical Change? Or striking a match? In this...

These days, it seems like we're finding water all over the solar system. Still, it takes a lot more than a little H2O to support life.

In this video Paul Andersen explains the importance of oxygen in accepting electrons. He begins with a brief description of combustion. He then explains the role of oxygen in aerobic cellular respiration.

Paul Andersen explains how organs work together to form organ systems and how organ systems work together to form organisms. The kidney and bladder work together to filter blood in the excretory system. The circulatory and respiratory...

Paul Andersen differentiates between biotic and abiotic factors. He explains how both abiotic and biotic factors can affect organisms at the level of the cell, the population and even the ecosystem. The complexities of biofilms,...

Paul Andersen surveys the circulatory system in humans. He begins with a short discussion of open and closed circulatory systems and 2,3, and 4-chambered hearts. He describes the movement of blood through the human heart and the blood...

Hank takes us on a trip around the body - we follow the circulatory and respiratory systems as they deliver oxygen and remove carbon dioxide from cells, and help make it possible for our bodies to function.

Oxidation-reduction reactions are going on around us, and inside us, all the time, and we can make redox reactions in organic chemistry easier to understand by tracking carbon-oxygen bonds. In this episode of Crash Course Organic...

In which Hank details the five scariest things that will likely happen because of climate change.

In this video Paul Andersen shows how carbon dioxide in the atmosphere is causing a decrease in the pH of the oceans. The carbon dioxide combines with the water to create carbonic acid which dissociates into bicarbonate and carbonate...

In this video Paul Andersen describes both weather and climate. Weather is the day-to-day conditions on the Earth's surface, including temperature, wind, humidity, air pressure, and precipitation. Climate are the long term conditions...

With a solid understanding of biology on the small scale under our belts, it's time for the long view - for the next twelve weeks, we'll be learning how the living things that we've studied interact with and influence each other and...

Paul Andersen explains how graphs are used to visually display data that is collected in experimentation. He describes five main types of graphs; line graph, scatter plot, bar graph, histogram and pie chart. He describes the important...

Paul Andersen explains pH as the power of hydrogen. He explains how increases in the hydronium ion (or hydrogen ion) concentration can lower the pH and create acids. He also explains how the reverse is true. An analysis of a strong...

In this video Paul Andersen explains how the climate on the earth is affected by the amount of solar radiation and the greenhouse affect. The addition of anthropogenic greenhouse gases has led to global warming which is impacting humans...

Mr. Andersen walks you through the cellular respiration lab.

Paul Andersen covers the processes of aerobic and anaerobic cellular respiration. He starts with a brief description of the two processes. He then describes the important parts of the mitochondria. He explains how energy is...

Sustaining life requires substantial energy and matter inputs. The complex struc- tural organization of organisms accommodates the capture, transformation, trans- port, release, and elimination of the matter and energy needed to sustain...

In this video Paul Andersen explains how fossil fuels are formed when organic material is heating and squeezed in an anaerobic environment. Formation, extraction, advantages, and disadvantages are discussed for coal, petroleum and...