Paul Andersen shows you how we can use a spreadsheet to model population changes. He begins with a brief discussion of populations and life cycles. He then shows you how you can model a single generation using a spreadsheet.

In this video Paul Andersen explains how standing waves are created through the reflection and interference of traveling waves. Destructive interference creates areas of no movement called nodes. Constructive interference creates areas...

Paul Andersen describes how cells move materials across the cell membrane. All movement can be classified as passive or active. Passive transport, like diffusion, requires no energy as particles move along their gradient. Active...

Paul Andersen explains how organisms respond to the external environment. He begins with a discussion of behavioral responses like hibernation and migration. He ends with a discussion of physiological responses like shivering and...

Paul Andersen describes microevolution and macroevolution in the stickleback fish of Loberg Lake. He describes how anadramous fish repopulated the lake after poisoning and adapted to the new environment through natural selection. He also...

In this video Paul Andersen explains how you can use the Gibbs Free Energy equation to determine if a process is spontaneous or not spontaneous. If the _G is less than zero the process is spontaneous. If the _G is greater than zero the...

Paul Andersen starts this video with a description of the respiratory surface. He explains how worms, insects, fish and mammals take in oxygen and release carbon dioxide. He then tours the major organs of the respiratory system; from the...

Paul Andersen starts with a brief description of asexual and sexual reproduction. He explains how meiosis ensures variation in the next generation. He describes the important structures in the male and female reproductive system. He...

In this video Paul Andersen explains the different forms and units for energy. A discussion of the laws of thermodynamics is also included. Sample conversion problems using dimensional analysis is also included.

The wave model of the electron can be used to explain the Bohr model. Electrons are found in certain orbits because they interfere with themselves and create standing waves. When the wavelengths don't match up with a whole integer they...

In this video Paul Andersen explains how economic models, like supply and demand, can be applied to environmental systems. The market forces will not protect environmental services until proper valuation and externalities are...

Paul Andersen defines the major elements of feedback loops. The receptors and effectors both sense and respond to changes in their environment. The following examples are used to illustrate the importance of feedback loops in maintaining...

In this video Paul Andersen explains the major phases of meiosis including: interphase, prophase I, metaphase I, anaphase I, telophase I, cytokinesis, interphase II, metaphase II, anaphase II, and telophase II. He explains how variation...

In this video Paul Andersen explains how to have your students engage in argumentation in the science classroom.

In this video Paul Andersen shows conceptual thinking in a mini-lesson on proportional relationships. TERMS Quantities - the amount (or number) of a thing Proportional relationship - relation of one dataset to another dataset Directly -...

In this video Paul Andersen describes the intermolecular forces associated with dipoles. A dipole is a molecule that has split charge. Dipole may form associations with other dipoles, induced dipoles or ions. An important type of...

In this video Paul Andersen explains how ecosystems respond to disruptions. Disruptions can cause changes in the number and variety of organisms. It can also lead to migration, extinction or even speciation. Ecosystems that have a higher...

In this video Paul Andersen explains that entropy is simply the dispersion of matter or energy. He begins with a series of video that show the natural direction of processes. According to the second law of thermodynamics the entropy may...

Paul Andersen explains the concepts of genetics. He starts with a brief discussion of the nature vs. nurture debate and shows how epigenetics blurs this distinction. He explains how differentiation of cell types results from the...

Paul Andersen explains how populations experience exponential. He begins by address the major players; N (population size) and r (growth rate). He models population growth in rabbits through four generations. He then shows you how to use...

In this video Paul Andersen explains how all objects contain positive and negative charge. Neutral objects contain an equal amount of positive and negative charges. Charged objects have more positive or negative charges. Like charges...

Mr. Andersen shows you how to interpret a position vs. time graph for an object with constant velocity. The slope of the line is used to find the velocity. A phet simulation is also included.

In this video Paul Andersen explains how the three types of catalyst classes act to speed up reactions. Acid-base catalysts either add or remove a proton from one of the reactants. Surface catalysts provide active sites where reactants...

Paul Andersen explains how we perceive our environment using our sensory system. He starts with a brief discussion of action potentials and the nervous system. He shows that we many more than five senses. He goes into more detail to show...