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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 2-minute video lesson provides an overview of early development of a zygote to an embryo. It also discusses embryonic and somatic stem cells. [Biology playlist: Lesson 12 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

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

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 10-minute video lesson shows how how myosin and actin interact to produce mechanical force. [Biology playlist: Lesson 47 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 13-minute video discusses how the Owl Butterfly may have gotten the spot on its wings. [Biology playlist: Lesson 5 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 16-minute video lesson looks at how one neuron can stimulate (or inhibit) another neuron at a chemical synapse. [Biology playlist: Lesson 46 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 17-minute video lesson looks at oxidation and reduction in cellular respiration. It Reconciles the biology and chemistry definitions of oxidation and reduction. [Biology playlist: Lesson 23 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

This 5-minute video lecture looks at oxidative phosphorylation and chemiosmosis (along with slight correction of previous video). [Biology playlist: Lesson 27 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.