Paul Andersen explains the niche. He gives three different pronunciations and two different definitions. He then discusses the competitive exclusion principle and the idea that a niche cannot be shared by two species.

Paul Andersen begins this podcast with a discussion of brain lateralization and gives a brief demonstration of tests that were performed on split-brain individuals. He then discusses the major parts of a neuron and explains how action...

Paul Andersen explains how organisms regulate timing and control. Phototropism and Photoperiodism allow plants to respond to light throughout the day and year. Circadian rhythms are used in all organisms (including animals) as an...

In this video Paul Andersen details the action potential in neurons. The resting potential of a neuron (-70mV) is maintained through differences in concentration and permeability of Na, K, and Cl ions. A graded potential is created as...

Paul Andersen shows you how to compare DNA sequences to understand evolutionary relationships. He starts with a brief introduction to cladograms and evolutionary relationships. He shows you how to classify DNA relationships using a...

Paul Andersen starts with a brief description of the history of life. He then discusses the seven characteristics of life and why viruses are not alive. He then describes the three domains in the current classification system and...

In this video Paul Andersen shows you how a cross between mutant and wild types of Sordaria fimicola can be used to show and measure frequency of crossing-over. He begins by reviewing the process of meiosis in a typical organism. He...

Paul Andersen explains how genes control the timing and coordination of embryo development. Seed germination initiates the discussion of cell differentiation. The SRY gene and genetic transplantation shows the importance of embryonic...

Paul Andersen explains the major elements in the endocrine system. He explains how glands produce hormones which target cells. He differentiates between water soluble and lipid soluble hormones. He then describes the hormones and actions...

Paul Andersen describes the structure and function of the major organelles in a eukaryotic cell. The endoplasmic reticulum, ribosomes, and golgi complex produce and store proteins in the cell. Lysosomes dissolve broken and invasive...

Paul Andersen shows you how to calculate the ch-squared value to test your null hypothesis. He explains the importance of the critical value and defines the degrees of freedom. He also leaves you with a problem related to the animal...

Paul Andersen explains how biology is ordered in the hierarchy of life. He first of all describes how emergent properties appear as you move to more inclusive systems. The then describes life at the following levels; atom, molecule,...

Paul Andersen introduces the topic of Biology. He covers each of the four main ideas that were developed by the College Board. These ideas revolve around the concepts of evolution, free energy, information and systems.

Paul Andersen starts with a brief description of feeding methods. He then details all of the major parts within the human digestive system. This tour starts in the mouth, move down the esophagus, through the stomach, small investing,...

Explore the endocrine system with the Amoeba Sisters! This video briefly discusses endocrine vs exocrine before showing major endocrine glands and discussing examples of hormones released by each gland. Video also provides an example of...

In this podcast Paul Andersen explains how cells differentiate to become tissue specific. He also explains the role of transcription factors in gene regulation. The location of a cell within the blastula ultimately determines its fate....

Paul Andersen explains how populations eventually reach a carrying capacity in logistic growth. He begins with a brief discussion of population size ( N ), growth rate ( r ) and exponential growth. He then explains how density...

Explore how substances travel in diffusion with the Amoeba Sisters! This video uses a real life example and mentions concentration gradients, passive transport, facilitated diffusion, and explains why diffusion is critical for all...

Paul Andersen explains the importance and structure of nucleic acids. He begins with an introduction to DNA and RNA. He then describes the important parts of a nucleotide and shows how they are connected through covalent and hydrogen...

Paul Andersen explains how X inactivation works in mammals. This process was first described by Mary Lyon. Each cell in a female will have on activated and one inactivated X chromosome. This explains why almost all calico cats are...

Paul Andersen starts with a brief description of enzymes and substrates. He then explains how you can measure the rate of an enzyme mediated reaction. Catalase from yeast is used to break hydrogen peroxide down into water and oxygen. ...

Paul Andersen defines microevolution as any change in the frequency of the allele pool. He then explains the five mechanisms of evolution; small sample size, non-random mating, mutations, gene flow and natural selection.

Paul Andersen explains how hugs between tissues can help maintain homeostasis. Countercurrent heat exchange allows heat to stay within the core of the body. Close contacts between the capillaries and alveoli allow our body to maintain...

Paul Andersen explains how eukaryotic cells use compartmentalization to increase the surface area and level of specialization within the cell. Prokaryotic and eukaryotic cells are compared and contrasted. The role of both the...