Question 1

The primary reason for the incredible success of viruses in their incredible diversity. The primary sources of this diversity are

Question 2

Briefly describe why viruses are said to exist as populations of sequences and not single sequences. What is the technical term for this concept.

Question 3
The primary reason Human infections by Ebola virus are largely localized to parts of Africa is which of the following (select one)?
Answer

A. Africans have a gentic polymorphism that enhances their resistance to malaria, but makes them more susceptible to Ebola (and other filovirus) infections.

B. Ebola is used as a bio-weopon by government militias fighting political instability in central Africa.

C. The primary animal reservoir for the Ebola virus is geographically restricted to Africa

D. The warm dry climate in Africa enables the virus to remain active outside the host for extended periods.

Question 4
The higher the mutation rate of an RNA virus, the more likely the virus will be able to succeed.

AnswerTrueFalse

Question 5
Although the polio virus has been around for centuries, it only became a significant health problem in the developing world in the 20th century due to (select one)?

Answer
Polio was transmitted to humans by a zoonosis in the 1930’s
Vaccination programs for polio began
Loss of natural vaccination due to improved sanitation.
Virus evolved to more pathogenic form
Humans were better able to travel and migrate which enhanced dissemination of the virus

Question 6
The graph below shows the relationship between viral genome size and mutation rate. Explain the observed relationship between genome size and mutation rate (3-5 sentences max).

Note: The mutation rate is expressed as the number of substitutions per nucleotide per generation,. For viruses a generation is defined as a cell infection in viruses (?s/n/c).

Question 7
Coronaviruses are a class of ssRNA viruses that are responsible for a number of respiratory diseases including SARS and the recently identified Middle Eastern Respiratory Syndrome (MERS). Coronaviruses are the largest known RNA viruses with genomes ranging from 26-32 kb. Coronaviruses are able to achieve such large genomes because they possess a gene not found in other RNA viruses. Using what you have learned this semester, speculate in 3-4 sentences the likely function of this gene that enables coronaviruses to possess such large genomes. Justify your answer.

Question 8
RNA viruses tend to occupy broad ecological niches with multiple host species, while DNA viruses tend to coevolve with host with fewer host species.

AnswerTrueFalse

Question 9

List three factors that explain why there appears to be an increase in the number Emerging Viral Diseases globally. Justify each factor in 1-2 sentences.

Question 10

Match the following Emerging viruses with the disease or symptoms they cause.

Polio Virus
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West Nile Virus
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Sin Nombre
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Severe Acute Respiratory Syndrome Virus
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Variloa
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Answer
A. Transmission of virus to humans is highly dependent on climate/weather because it influences populations of rodent vector
B. Emerged due to improved sanitation that broke natural vaccination cycle
C. Virus was brought to Americas by earlier explorers. Beliveved to have wiped out native populations because they did not have immunity to virus.
D. First major viral epidemic documented to be spread by air travel
E. Brought to United States by insect vector

Question 11
Explain why a virus that is well adapted to one species and causes no apparent disease can upon a switch to a new host range cause severe disease (Max 3-5 sentences)?

Question 12

What is the last name of the scientsist who accredited with the following quote:

“In the battle by attrition, humans have a real problem competing with microorganisms. Here we are, here are the bugs, they’re looking for food, we’re their meal in one sense or another, how do we compete?”