[Free Registration/Login may be required to access all resource tools.] Humans are in the same domain as trees and algae. What could they possibly have in common? It is the location of their DNA inside their cells. Their cells all have a...

Describes the characteristics of Archaea, Bacteria, and Eukarya, the three domains of life.

Explore the three domains of life.

This tree of life is presented in an outline format. The outline is arranged in a hierarchical manner organized from the largest group (domain) to the smallest group (class). This interactive outline includes pictures of fossils and...

In this online biology textbook, learn about the two prokaryotic domains of life, which include eubacteria and acrhaebacteria.

What is it that distinguishes a living organism from a nonliving object? This collection of images presents examples that aren't as clear-cut as one might think, enticing students to question the meaning of life.

This image from Biology by Kenneth R. Miller and Joseph Levine illustrates the relationship between structure and function by comparing the jaws and teeth of two animals with very different ways of life: the wolf and the horse.

This video segment adapted from NOVA goes on a whimsical journey in search of life forms thriving in extreme conditions on Earth and in outer space. Animations show ice on Jupiter's moon, Europa, and signs that water once existed on...

Learn about different forms of life that coexist with us on Earth. This Berkeley article provides links to brief write-ups on the three domains of living organisms: Eukaryota, Bacteria, and Archaea.

This video segment from NOVA: "The Mystery of Animal Pathfinders" explores the migratorial exploits of monarch butterflies. [4:39]

This video segment explores the role of touch in the development of young animals, including humans. Footage from NOVA: "Mystery of the Senses: Touch." [2:57]

This video segment explores the sense of taste in humans -- why we have it, and what happens when we lose it. Footage from NOVA: "Mystery of the Senses: Taste." Includes background reading material and discussion questions. [4:18]

Learn about the biosphere, when it originated, how life sustains itself, and what processes occur.

An online course with interactive activities and learning exercises give students the opportunity to look at the tree of life and to determine how and why scientists believe each domain, species, and everything in between have such...

Travel deep into the human body to see exactly where your DNA resides. From the NOVA: Cracking the Code of Life Web site.

Are nature's complex forms evidence of "intelligent design"? In this Evolution essay, biologist Kenneth Miller explains how the processes of evolution account for complex structures such as the human eye.

This illustrated timeline from the NOVA Web site follows Albert Einstein's life, including 1905, his "Miracle Year," during which he developed his Special Theory of Relativity and the equation, E=mc2.

This illustrated timeline from the NOVA Web site turns back the clock to the late 1500's to relive the dramatic life of one of the world's most renowned scientists.

This video segment from NOVA: "Sea Behind the Dunes" tracks the return of spawning alewife fish from the open ocean back to the freshwater streams and ponds where they were born. [3:34]

[Free Registration/Login may be required to access all resource tools.] An introduction to the method of biological classification developed by Carl Linnaean.

The disappearance of bees will have tremendous impact upon the way we live according to scientists in this segment from Nature.

Fevers are a sign of infection, but they may also be part of the cure. This drawing illustrates Matthew Kluger's lizard study, which supports the notion that fever can be beneficial.

This video segment adapted from NOVA/FRONTLINE looks at American energy consumption and the resulting production of greenhouse gases. [4:59]

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.