Name: Understanding Viruses. HIV, Herpes, Influenza, small pox, chicken pox, measles, mumps, bird flu, swine flu.

Transcription

1 Name: Understanding Viruses Section 1 1. List as many viruses as you can. HIV, Herpes, Influenza, small pox, chicken pox, measles, mumps, bird flu, swine flu. 2. How do viruses reproduce? (aside from the video explanation, see pgs in the text). They inject their DNA into living cells and use the cell s machinery to manufacture more virus. Viruses can exist in two different ways: the lytic cycle and the lysogenic cycle. (see the shared folder for a diagram comparing the two or pg ). Some viruses go through just the lytic cycle, just the lysogenic cycle and some go through both. 3. Explain how World War I contributed to the flu pandemic of 1918? For the first time in history, large numbers of people from different parts of the world came in direct contact with each other. More people died from infectious disease during the war than soldiers killed in action

2 4. Who was immune to small pox? Why were they immune? Milkmaids were immune to small pox because of their exposure to cow pox; a condition similar enough to small pox that allowed them to develop antibodies. 5. Explain the work of Edward Jenner. He extracted the fluids from the blisters of cow pox victims and injected his son with it. He then exposed his son to a live small pox virus, and though he suffered a mild sickness, lived. This was the first vaccination 6. How are flu vaccines made? Flu viruses are grown in chicken embryos. After a while, they become adapted to living in chicken cells rather than human cells. When a human is injected, the virus initiates a response from the immune system. 7. Explain the work of Jonas Salk? Jonas Salk created the polio vaccine. His approach was different than Edward Jenner in that he did not use a live form of the disease. This would become the modern way to produce vaccines for many other diseases

3 Section 2 1. What are some ways to fight against viruses? Immunizations at birth and then booster shots throughout your life. Sanitation is also important. Finally, education is crucial, so you know how to avoid the virus in the first place. The number one reason there are millions of AIDS cases in Africa is lack of education. 2. What disease went extinct? When did this happen? Small pox became extinct in 1978 after the last patient was immunized for it. There are two labs that house smallpox virus; one in the U.S. and the other is in Russia. There has been pressure from many organizations to destroy these last remnants. (Smallpox virus) 3. What are viral emergents? Viral emergents are old viruses looking for new hosts. As people push into new habitats, one real concern is the release of new viruses to our bodies that have no protection against them.

4 4. Why is it so important for virologists to study life forms in tropical rainforests? Many species are unknown and may be hosts to new, unidentified viruses that could affect us. By studying these life forms and the viruses that live in them, we will be better prepared to deal with them. 5. What is HIV? Where did it originate and how did it spread? Human Immunodeficiency Virus destroys your immune system. It began in monkeys and spread from local villages to larger populations. Coupled with world travel and specific behaviors, this led to the AIDS epidemic of the 1980 s. (HIV 100 billionths of a meter!) 6. How might viruses help cure genetic disease? Provide a specific example. Viruses can be used in genetic engineering. Specifically, they can act as delivery systems for genes we want placed in a cell. People with cystic fibrosis (a disease of the lungs) are responding well to a treatment whereby the common cold virus has been engineered to deliver working copies of the mutant gene. Tobacco plants are also being used to make antibodies to treat Ebola infections (ZMAPP)

5 Things you may want to check out on your own.