The following books and websites contain additional information, activities, and enrichment options.

Cells and Systems

Holly Wallace, Heinemann, 2003

The Diversity of Life: From Single Cells to Multicellular Organisms

Robert Snedden, Heinemann, 2002

The World of the Cell: Life on a Small Scale

Robert Snedden, Heinemann, 2002

Classification

Holly Wallace, Heinemann, 2000

Plant Classification

Louise and Richard Spilsbury, Heinemann, 2003

Classifying Mammals

Andrew Solway, Heinemann, 2003

The Electronic Naturalist

http://www.enaturalist.org/

North American Mammals

http://www.mnh2.si.edu/education/mna/

For additional websites, see the Best of the Net feature at www.eduplace.com/science and sites recommended by the National Science Teachers Association at www2.nsta.org/sciencesites/