This 14-minute video lesson provides an overview of B cells (B lymphocytes) and how they are activated and produce antibodies. [Biology playlist: Lesson 53 of 71].

This 18-minute video lesson provides an introduction to bacteria. [Biology playlist: Lesson 18 of 71].

This 17-minute video lesson looks at C-4 Photosynthesis: How some plants avoid photorespiration. [Biology playlist: Lesson 33 of 71].

This 9-minute video lesson looks at how CAM Plants are able to fix carbon at night so they don't have to keep their stomata open during the day. [Biology playlist: Lesson 34 of 71].

This 13-minute video lecture provides an introduction to what cancer is and how it is the by-product of broken DNA replication. [Biology playlist: Lesson 13 of 71].

This 18-minute video lesson looks at the the vocabulary of DNA: chromosomes, chromatids, chromatin, transcription, translation, and replication. [Biology playlist: Lesson 8 of 71].

This 15-minute video lesson provides an introduction to the circulatory system and the heart. [Biology playlist: Lesson 39 of 71].

This 7-minute video lesson provides a correction to Sodium and Potassium Pump Video. [Biology playlist: Lesson 43 of 71].

This 10-minute video lesson discusses how cytotoxic T-Cells get activated by MHC-I/antigen complexes and then proceed to kill infected cells. [Biology playlist: Lesson 56 of 71].

This 28-minute video lesson provides an introduction to DNA. [Biology playlist: Lesson 6 of 71].

This 19-minute video lesson looks at diffusion and osmosis. [Biology playlist: Lesson 36 of 71].

This 17-minute video lesson presents an overview of the Electron Transport Chain. [Biology playlist: Lesson 26 of 71].

This 13-minute video lesson provides an overview of glycolysis. [Biology playlist: Lesson 24 of 71].

This 21-minute video lesson provides an introduction to helper T-Cells and their role in activating B cells. [Biology playlist: Lesson 55 of 71].

This 15-minute video lesson examines hemoglobin and its role in the circulatory system. [Biology playlist: Lesson 40 of 71].

This 15-minute video provides an overview of the inflammatory response. [Biology playlist: Lesson 58 of 71].

This 14-minute video lesson presents an introduction to cellular respiration, glycolysis, the Kreb's Cycle, and the electron transport chain. [Biology playlist: Lesson 21 of 71].

This 18-minute video lesson provides an introduction to evolution, variation in a population, and Natural Selection. [Biology playlist: Lesson 1 of 71].

This 17-minute video lesson provides an introduction to heredity and classical genetics. It looks at dominant and recessive traits as well as heterozygous and homozygous genotypes. [Biology playlist: Lesson 14 of 71].

This 18-minute video lesson provides an overview of the Krebs or Citric Acid Cycle. [Biology playlist: Lesson 25 of 71].