Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Polyadenylation wikipedia , lookup
Nucleic acid tertiary structure wikipedia , lookup
RNA silencing wikipedia , lookup
Non-coding RNA wikipedia , lookup
History of RNA biology wikipedia , lookup
DNA vaccination wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
MCDB 1030 Spring 2005 Homework Set 3 Viruses and The Immune System 1. What kinds of nucleic acids may be found in viruses? 2. What is the difference between a + strand and a – strand of RNA? 3. Describe the principle events that occur in the life cycle of a + strand RNA virus. 4. What do the following enzymes do? In each case, indicate the type of organism in which the enzyme is required. (For viruses, specify the type of virus.) a) RNA-dependent DNA polymerase b) RNA-dependent RNA polymerase c) DNA-dependent DNA polymerase d) DNA-dependent RNA polymerase 5. Summarize the first, second, and third lines of defense against invading pathogens. 6. What is phagocytosis? Why is it important? 7. The complement system contributes to destruction of bacteria in three important ways. What are they? 8. What is inflammation? Is it beneficial or harmful? 9. Define the following terms: a) antigen b) humoral immunity c) cell-mediated immunity d) interferon e) lymph 10. Diagram an antibody molecule and label the heavy and light chains, and the constant and variable regions. Draw a cartoon of two antibodies that are specific for molecules of different shapes, and show why they would not cross-react. 11. What are the roles of each of the following in the immune response? a) helper T cells b) cytotoxic T cells ( a.k.a. killer T cells) c) B cells d) Cytokines e) MHC proteins f) Antigen-presenting cells g) CD4 receptor h) CD8 receptor 12. Why are both humoral immunity and cell-mediated immunity important for fighting a viral infection?