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...

Join The Amoeba Sisters as they explain the biotechnology PCR. This video goes into the basics of how PCR works as well as two examples of its potential use. Table of Contents: 00:00 Intro 1:34 How does PCR work? 4:31 Why use PCR? 5:10...

Explore DNA structure/function, chromosomes, genes, and traits and how this relates to heredity! Video can replace old DNA structure & function video and in addition covers foundational concepts of heredity. Table of Contents: Video...

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.

Explore one of the most fascinating processes plants can do: photosynthesis! In this Amoeba Sisters updated photosynthesis video, you will find a general overview of the light dependent and light independent reactions (Calvin Cycle) and...

Paul Andersen shows you how to construct a cladogram from a group of organisms using shared characteristics. He also discusses the process of parsimony in cladogram construction. He then explains how modern cladograms are constructed...

Join the Amoeba Sisters in their updated plant structure and adaptations video as they discuss the terms vascular vs nonvascular and how they relate to plants before exploring some general categories of plants (bryophytes, seedless...

Paul Andersen explains how signal transduction pathways are used by cells to convert chemical messages to cellular action. Epinephrine is used as a sample messenger to trigger the release of glucose from cells in the liver. The...

Explore autosomal recessive trait and X-linked recessive trait tracking in pedigrees with the Amoeba Sisters! Table of Contents: Intro 00:00 Introducing Symbols/Numbering in Pedigree 0:40 Meaning of Shading in Shapes 1:19 Introducing...

Explore chromosomes and karyotypes with the Amoeba Sisters! This video explains chromosome structure, how chromosomes are counted, why chromosomes are important, and how they can be arranged in a karyotype! This video also tackles a few...

Paul Andersen explains how disruptions in homeostasis can affect biological systems at all levels. He uses the example of dehydration in animals to explain how disruptions at the cellular level can affect an organism. He also uses the...

Paul Andersen describes how free energy is used by organisms to grow, maintain order, and reproduce. A brief discussion of the first and second law of thermodynamics is also included. Disruptions in the amount of free energy can cause...

Paul Andersen explains how feedback loops allow living organisms to maintain homeostasis. He uses thermoregulation in mammals to explain how a negative feedback loop functions. He uses fruit ripening to explain how a positive feedback...

Mr. Andersen gives a brief description of osmosis. He explains how water moves from a hypotonic to a hypertonic solution across a semipermeable membrane. The video ends with a time-lapse demon in class.

Explore the cell cycle with the Amoeba Sisters and an important example of when it is not controlled: cancer. Table of Contents: 00:00 Intro 1:00 Cell Growth and Cell Reproduction 1:42 Cancer (explaining uncontrolled cell growth) 3:27...

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...

Mr. Andersen shows you how to convert moles to grams and moles to molecules.

Paul Andersen shows you how to solve simple Hardy-Weinberg problems. He starts with a brief description of a gene pool and shows you how the formula is derived. He then shows you how to solve a couple of sample problems.

Paul Andersen explains the two major portions of the molecular biology lab in AP Biology. He starts by discussing the process of transformation. He explains how you can use the pGLO plasmid to produce glowing E. coli bacteria. He then...

Mr. Andersen talks you through the diffusion demo. After you finish watching this video you should be able to rank the following from smallest to largest: starch, glucose, water, IKI and the pores in the dialysis tubing.

Paul Andersen explains how pigments can be separated using chromatography. He shows how you can calculate the Rf value for each pigment. He then explains how you can measure the rate of photosynthesis using leaf chads and water...

What happens when you can't do aerobic cellular respiration because oxygen isn't available? Explore fermentation with The Amoeba Sisters! This video focuses on alcoholic fermentation and lactic acid fermentation, and it also mentions how...