Biology students can now perform frog dissections online with this interactive virtual frog dissection kit.

Phenomenon is due to chemical reactions in viable systems and results in the production of light.

Virtual encyclopedia explains the basic nature and uses for human, animal, and plant breeding. Includes info about professional breeders.

Features a definition of animal sound waves used to pinpoint locations. Link to profiles of animals who utilize this function.

Learn about this respiratory organ, its functions, and its ability to obtain oxygen from water.

Guide to this chemical-producing organ includes an introduction and examples of its two major types.

Article on this iron-protein compound describes its functions, and its use in the human blood system.

Peruse a description of this dormant state, and profiles of different animals which undergo hibernation.

Find a description of this anatomical feature's composition, and details on its functions. Link to horned animal overviews.

Browse a description of elephant tusks, including details on its composition, uses, and legal regulations. Link to related resources.

Introduces the composition and formation of the proteins that make up hair, nails, horns, and feathers.

Description of this lymphatic system fluid includes an explanation of its uses. Link to related overviews.

Biological discussion gives a definition of the two kinds of mimicry, a natural phenomenon marked by advantageous resemblance between species.

Encyclopedia entry presents a definition of the term as applied to animals.

Provides a definition of the term and compares the invertebrate form with the vertebrate. Open the links to teeth, salivary glands, and palate.

Provides a definition of the term used to describe an animal's diet composition.

Describes the location of these glands and the functions of saliva.

Peruse this encyclopedia entry which provides a definition and scope of the term and a discussion on heredity.

Find an encyclopedia entry which discusses the structure and components of exoskeletons and endoskeletons.

Encarta provides an encyclopedia article about wool, cross referenced with links to related topics. Also learn about their premium services.