Friday, September 7, 2012

The Molecule That Supports All of Life

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As astronomers study newly discovered planets orbiting distant stars, they hope to find evidence of water on these far-off celestial bodies,...

Charles Darwin and the Theory of Natural Selection

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The history of life, as documented by fossils and other evidence, is a saga of a changing Earth billions of years old, inhabited by an evol...
Wednesday, July 18, 2012

Evolution Accounts for the Unity and Diversity of Life

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The list of biological themes discussed under Concept 1.1 is not absolute; some people might find a shorter or longer list more useful. Ther...
Monday, July 16, 2012

Feedback mechanisms regulate biological systems

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A kind of supply-and-demand economy applies to many biological systems. Consider your muscles, for instance. When your muscle cells require ...

Systems Biology at the Leyels of Cells and Molecules

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The entire sequence of nucleotides in the human genome is now known, along with the genome sequences of many other organisms, including bact...
Friday, July 13, 2012

The continuity of life is based on heritable information in the form of DNA

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Inside the dividing cell in Figure 1.7 (on the previous page), you can see structures called chromosomes, which are stained with a blue-glow...

Cells are an organism's basic units

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In life's structural hierarchy, the cell has a special place as the lowest level of organization that can perform all activities requir...