In this video segment adapted from NOVA scienceNOW, scientists discuss their attempts to grow human body parts in a jar.

Find out how serious head concussions can be in this video segment adapted from NOVA scienceNOW.

In this video segment adapted from NOVA scienceNOW, scientists discuss a family of genes called FOXO that can significantly extend life span in worms—and in humans.

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

Students explore cell structures, the role of the membrane, and the similarities and differences among specialized cells.

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.

This video segment adapted from A Science Odyssey tells the story of researcher Sir Alexander Fleming, whose luck and scientific reasoning led to the groundbreaking discovery of penicillin.

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.

In this media-rich lesson, students analyze structure and function relationships at different levels of organization in nonbiological systems and then perform a similar analysis using biological systems.

In this media-rich lesson, students explore the preservation and expression of genetic information within the cell. They analyze a short DNA sequence, translate an RNA sequence, and relate a sequence difference to a particular trait.

While all cells have a great deal in common, there is no end to the variation among them. These images provide a sense of the wondrous diversity found in the world of cells. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

This animation produced by WGBH and Digizyme, Inc. demonstrates the techniques researchers use to isolate transformed bacteria and expand their population in order to obtain large quantities of a protein of interest.

In this interactive activity from the Exploratorium, explore the steps of protein synthesis in which the cells use genes to make proteins for critical body functions. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

In this video segment adapted from NOVA, follow novice runners as they train for a marathon, and discover how quickly the body responds to regular aerobic exercise.

In this video segment from The Secret of Life Teaching Modules: "Nothing to Sneeze At: Viruses," watch as a virus attacks a cell, and learn how the immune system reacts to this onslaught.

This essay by Patti and Warren Finke describes the process by which our bodies transform food energy into energy that our cells can use. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

In this video segment adapted from Rx for Survival, watch a graphic representation of the malaria parasite and hear from experts about the physical and economic effects of the disease on the human population, as well as treatments and preventive measures.

In this lesson from NOVA scienceNOW, students explore how our bodies respond to exercise at the cellular level.

Often referred to as the powerhouses of the cell, mitochondria provide the energy that powers nearly every cellular process. This essay by John Ross describes in detail the structures and functions of these amazing organelles.