The University of Arizona Biology Project: "Viruses Tutorial"
Read this page, and then click on the "Next" button on the bottom of the page. On the next page choose "What is alive?" This is a multiple-choice assessment. Choosing an option will bring you to a page that indicates whether you answered correctly or incorrectly and provides a short explanation. If you answer incorrectly, click on "try again" to repeat the question. If you answer correctly, click on the link to the next problem.