7.1+Questions+-+Rachel

7.1 (p.122-124) and Avian Flu p. 125 //1. Why are viruses not exactly living or nonliving?// When a virus is not in a host it is just a chemical, but when inside a host cell the virus can replicate and in turn be considered living.

//2. Give some examples of diseases caused by viruses.// Colds, flu, measles, chicken pox, polio, rabies, AIDS, and genital warts/herpes.

//3. What is the basic structure of a virus? (The two parts and their function)// All viruses are made up of two parts: 1) an outer capsid composed of protein subunits and 2) a nucleic acid core composed of either DNA or RNA. Once inside a host cell the nucleic acid codes for the protein units in the capsid.

//4. Why are viruses like microscopic pirates?// Because once inside a cell, it commands the metabolic machinery of its host cell.

//5. Why are viruses considered parasites?// Because viruses are acellular, that is not composed of cells and cannot live independently.

//6. Why are viruses considered OBLIGATE parasites?// Because in order for them to function (live) they must have a host cell.

//7. Why do viruses ALWAYS cause disease?// A virus (noncellular particle) cannot function unless inside a host cell. So if a virus is causing something that means it is within a host cell and reproducing, they only have one purpose that is to create a certain disease that the immune system will hopefully not recognize.

//8. How do viruses "emerge" and "spread" each year? Give examples.// Viruses emerge from the inability of the immune system to recognize it or changes in preexisting viruses, causing disease. Viruses can spread by being transported to a place that has not been before, such as the outbreak of SARS in Canada came from Southeast Asia. Another way a virus can spread is through a vector, usually a bug which carries the disease from an infected person to a healthy one. An example of a vector transmitted viral disease would be West Nile Virus which is carried by birds and mosquitoes.

//9. What is a virus vector? Give examples,// Transmits viral diseases by carry disease from an infected individual to a healthy one. Vectors are usually insects, such as mosquitoes.

//10. What is the relationship of bird flu to birds?// Birds contract the avian flu through saliva, feces, or mucus of an infected bird. Many strains have little to no effect on the bird, but in other very contagious strains the disease is fatal.

//11. How does bird flu infect humans?// Humans acquire the virus when in close contact with infected birds, almost 1/3rd of infected humans have died from the disease.

//12. What is a pandemic?// An increase in the occurrence of a disease within a large and geographically widespread population; a worldwide pandemic occurs globally.

//13. Why is there fear that bird flu could cause a pandemic?// Yes, if the a new hybrid virus were to form and infect humans it is very likely it would rapidly travel between countries, causing a global pandemic.

//14. What action can we take to prevent a bird flu pandemic?// First and foremost it is critical that the avian flu virus does not jump from a bird to a person, this increases the risk of a hybrid forming (a strain that could be transmitted person to person). Secondly, we must support scientists efforts in trying to find a vaccination for the constantly evolving virus. Where the bird flu virus has already hit, removal of all infected and potentially infected birds has shown to decrease the potential of spreading but has not eliminated the problem. We must also make sure to prevent the virus from infecting waterfowl, which migrate globally.