Print this Web Links Activity Log to record your findings. In order to view and print these activities, it is necessary to have Adobe Acrobat Reader. If you do not have this, get the free download now.   Click the Techie Toolbox for tips and help to make the most of your time on the Web. Chapter 21: Viruses and Bacteria Life's Extremists Archaebacteria live in environments that usually are considered inhospitable to other forms of life. Read this introduction to the Archae to learn more about this unique kingdom. The Mycobacteria Access this site for information about mycobacteria. Why can they be nicknamed the "ducks of the microbial world"? Of the more than 70 species of mycobacteria, what are the two major pathogens? What diseases do they cause? Creatures of Thermal Vents This site discusses the organisms found near hydrothermal vents. Click on giant tube worms to learn more about these fascinating creatures.