• Use the resources on the world wide web to investigate questions about Viruses, Monera, Protists and Fungi.

• I have selected three topics on which I am curious top find out more. For each topic I will review briefly what was covered in the text, then I will pose a question that extends beyond the information presented in the text. I will offer you some www URLs where you can investigate additional information on each topic. You can use CUT and PASTE to bring information, including graphics, back to this web page to include in your answers in addition to the writing that you do. You do not have to do the questions in order. As is common on the web, there is always more that you can find to investigate beyond the suggestions I am providing for you.

Dr. Paul Tabor

OK, here are the questions:

1. In chapter 28 in the section "Retroviruses Have RNA Genes", an unusual enzyme, reverse transcriptase, is introduced. Reverse transcriptase uses RNA as a template to synthesize DNA in the reproduction cycle of the retrovirus. The text goes on to say that retroviruses are of great interest because this group contains the HIV virus that causes AIDS in humans. Since retroviruses require reverse transcriptase to complete the process of infection of human cells, would it be possible to inhibit the enzyme reverse transcriptase and prevent or eliminate the HIV infection that leads to AIDS? Dr. Joel Gallant has provided some interesting information on recent research and clinical trials that have been done to explore the efficacy of the use of reverse transcriptase inhibitors. At Dr. Gallant's web site you can also find a question-and-answer forum where questions regarding AIDS treatments can be submitted to Dr. Gallant and he posts answers for all of us to read.  As you will see in reading the questions, many are from individuals who are HIV positive.

2. In chapter 28 in the section "Imperfect Fungi Reproduce Asexually Only" the important fungus genus Penicillium is described as an imperfect fungi. Well, Penicillium has been reclassified. How is it classiifed now? There are some resources that can shed light on this question. At the Oklahoma State there is a fungi library and one of the major sections is the Penicillium Library. In the Penicillium library, you should check under Penicillium and see the abstracts of articles by Verweij (1995) and Yamamoto (1995). You now should have an idea as to which genus of fungi Penicillium is closely related.  But which phylum of the kindom Fungi are we talking about? A phylogenic tree may help you see the relationships of different fungi. Species of Penicillium produce the antibiotic penicillin. The section of the text "Killing Microorganisms" declares that the growing resistance of bacterial strains to treatment with penicillin is the major concern in antibiotic therapy.  How does penicillin affect bacteria? How do bacteria fight back against this antibiotic that a fungus produces? Dr. Jack Brown in the Microbiology Department at the University of Kansas has written an interesting discussion on penicillin.  The answer to the question on how bacteria become resistant is in the section on penicllinase.

3. In the section "Sporozoa Form Spores", Pneumocystis carinii is discussed as a pathogen that causes pneumonia in AIDS patients. Although P. carinii had not been studied much in the past because it was not a major health problem, during the last 10 years this organism has received a great deal of attention.  Studies of the basic biology of the organism have revealed that it is not a protozoa at all.  In fact it is now recognized to belong in an entirely different kingdom!  What kind of organism is Pneumocystis carinii? You have done some investigating of Penicillium systematics in the question above. I am not going to give specific URLs to help you answer this question; however, if you were reading carefully about the phylogeny of Penicillium, you should recall the mention of Pneumocystis also.