Advanced chapter of the book "The Molecular Biology of the Cell" describes and provides illustrations of our most current understanding of the chemical makeup of cells and their components. Explains in detail how electron activity keeps...

This site from the U.S. Geological Survey provides great definitions of seven measurements that can be taken on water. Includes pH, dissolved oxygen, and turbidity. Click Home to access the site in Spanish.

Describes the physical characteristics of Daphnia, their importance as a food source for freshwater fish, their diet, life cycle, and methods of reproduction. Offers tips for how to start and maintain a colony of Daphnia that can be used...

Discusses the different types of bacteria with probiotic properties that are beneficial to humans' health. Also discusses bacteria that benefit water, soil, and plants.