Blood Vessels Help Tumors Grow

In this video segment, adapted from NOVA, Dr. Judah Folkman uses the scientific method to discover how cancer cells induce the formation of new blood vessels, which in turn nourish those cancer cells.

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Bt Corn

This video segment from FRONTLINE/NOVA: "Harvest of Fear" looks at corn that has been genetically modified to resist one insect pest, and the multiple concerns it raises.

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Caves: Extreme Conditions for Life

This video segment adapted from NOVA raises the provocative idea that if life can exist in the most extreme environments on Earth — such as in dark, toxic caves — then perhaps living things can also survive in harsh environments on other planets.

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Cell Differentiation

In this video segment from The Secret of Life school video, "Sex and the Single Gene" follow as a single fertilized egg cell divides, differentiates, and assembles into the tissues and organs of a new organism.

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Cell Division

In this interactive activity adapted from the Exploratorium, explore the step-by-step process by which an animal cell divides to make more cells.

Cell Membrane: Just Passing Through

This interactive feature describes some of the most important structures and functions of the cell membrane.

Cell Transcription and Translation

In this interactive activity adapted from the University of Nebraska, learn how and where transcription and translation occur within a cell and observe both processes in detail.

Classical vs. Transgenic Breeding

This video segment from FRONTLINE/NOVA: "Harvest of Fear" explains that genetic engineering and classical breeding both alter the genetic makeup of crop plants.

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The Common Genetic Code

Paul Nurse describes his research that showed that humans share some genes with organisms as different from us as simple brewer's yeast. Footage from Secret of Life: "Immortal Thread."

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Dengue Virus Invades a Cell

In this visualization adapted from the University of Massachusetts Medical School, discover the role that dengue viral proteins play in a human cell as the virus prepares to replicate.

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DNA Fingerprint Photos

These photographs supplied by Genelex Corporation depict actual DNA fingerprints and show the types of information that can be gleaned from them.

DNA Makes History

Read how DNA was used to solve the mystery of the Romanov family's execution. From Human Genetics: Concepts and Applications by Ricki Lewis.

DNA on the Witness Stand

In this article, Dr. Eric Lander of the Human Genome Project comments on the use of DNA as an identification tool -- the theoretical versus the practical results.

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DNA Separation Lab in the Classroom and in Real-World Research

This video produced by WGBH features students in the Amgen-Bruce Wallace Biotechnology Lab Program preparing a recombinant DNA molecule, and examines how this work relates to the way real-life scientists approach similar work.

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DNA Workshop

How does DNA perform those all-important functions of replication and protein synthesis? This interactive feature from the A Science Odyssey Web site will help you explore and understand the secrets of DNA.

Double Immunity

Dr. Stephen O'Brien of the National Cancer Institute discovers a 700-year-old mutation that makes a person resistant to HIV infection. From Evolution: "Evolutionary Arms Race."

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Electron Transport Chain

This illustration from Biology by Kenneth R. Miller and Joseph Levine describes the steps of the electron transport chain, the second stage in the process of cellular respiration.

Electrophoresis and Gel Analysis

In this animation produced by WGBH and Digizyme, Inc., see how molecules of DNA are separated using gel electrophoresis, and how this process enables scientists to compare the molecular variations of two or more DNA samples.

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The Embryo Takes Shape

This video segment from NOVA: "Life's Greatest Miracle" explores the developmental process of an embryo beginning just two weeks after fertilization.

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Explore a Stretch of Code

Try your hand at reading a segment of genetic code in this interactive feature from the NOVA "Cracking the Code of Life" Web site.