• The Biology Project - http://www.biology.arizona.edu/
  Covering several subtopics in Biology, this site from the University of Arizona includes tutorials and problem sets. Use the Site Map for ease in navigation.
• Biology Online Tutorials - http://www.biology-online.org/tutorials/home.htm
  Tutorials include cell biology, genetics, adaptation, developmental biology etc.
• Cells Alive - http://www.cellsalive.com/index.htm
  A tutorial on Cell Biology including topics such as mitosis and meiosis. The site includes many animations.
• Kimball's Biology Pages - http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/
  An online introductory Biology textbook written by a retired Harvard professor. Can be browsed or searched.
• NCBI Bookshelf - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Books
  Searchable full text collection of recent biomedical books.
• Net Frog - http://curry.edschool.virginia.edu/go/frog/
  Interactive site describing frog dissection in great detail.
• Online Biology Book - http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
  A well illustrated, well organized online biology book by a community college professor.

Search Engines and Journal Collections

• Entrez: the Life Sciences Search Engine - http://www.ncbi.nlm.nih.gov/query/gquery.fcgi
  This helpful search engine simultaneously searches a large number of bioscience, health science, biotechnology etc. Web sites published by the U.S. Government.
• Biomed Central - http://www.biomedcentral.com/home/
  A searchable online collection of scientific journals. A large number are free; some require subscription. The site allows you to search Biomed Central, PubMed or PubMed Central. Cost-free registration is required.
• PLoS Biology -
  http://biology.plosjournals.org/perlserv/?request=index-html&issn=1545-7885
  A quality online journal published by The Public Library of Science.
• PLoS Medicine -
  http://medicine.plosjournals.org/perlserv/?request=index-html&issn=1549-1676
  A quality online medical journal published by The Public Library of Science.

Lists of Helpful Web Sites

• Biology Browser - http://www.biologybrowser.org
  This source, from BIOSIS, a well known Biology publisher includes free resources, helpful links and article citations. It can be searched.
• Harvard Biopages - http://www.mcb.harvard.edu/BioLinks.html
  An extensive list of Biology Internet sites.
• World Wide Web Virtual Library Biosciences - http://vlib.org/Biosciences
  A lengthy, well organized set of links to high quality Web sites. An excellent resource.
  
  Individual Subjects
  
• Animal Diversity Web - http://animaldiversity.ummz.umich.edu/site/index.html
  "An online database of animal natural history, distribution, classification, and conservation biology."
• Bioethics Web - http://bioethicsweb.ac.uk/
  "A gateway to evaluated, quality Internet resources relating to biomedical ethics."
• Botany: The National Biological Information Infrastructure - http://www.nbii.gov/disciplines/botany/
  Exhaustive coverage of botany from the Federal government.
• DNA Interactive - http://www.dnai.org/index.htm
  An excellent introduction to DNA.
• Ecology WWW Page - http://www.botany.net/Ecology/
  Searchable list of up to date links to ecology Web sites.
• Human Genome Project - http://www.ornl.gov/sci/techresources/Human_Genome/home.shtml
  Describes the project that identifies the 20,000-25,000 genes in human DNA and the implications of the project.
• Integrated Taxonomic Information System - http://www.itis.usda.gov/
  "... authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world."
• Understanding Evolution - http://evolution.berkeley.edu/
  This award winning site explains evolution thoroughly.