Question

4. Using the terms you have learned in this class, explain what is meant by the following statement: (8 points)

“All viruses mutate.  However, a mutated virus is not necessarily more dangerous.”

Include answers to the following questions:

What is a mutation?

Are most mutations helpful or harmful to a virus?  Why?

What would make a virus “more dangerous” to humans?

5. Based on all the topics you have discussed Biol002 this quarter, what is one way the Corona virus pandemic will end?  Explain using the science terms you learned in class. (8 points)

Topics to include: what is a virus, vaccination, social distancing, SIR model of how diseases spread, mutation

Answer 1

4) What is a mutation?

A mutation is a change in the DNA sequence in an organism.

It can be caused by mutagens, DNA replication errors, DNA proof reading errors, etc.

This can also be true for RNA since RNA is the genetic code for some viruses (retro viruses).

Now specifically when we are taking about mutations in viruses. Viruses have a high mutation rate. RNA viruses mutate faster than DNA viruses while single stranded viruses mutate faster than double stranded viruses.

How are mutations beneficial.

One example is when a mutation changes the structure of the protein on the surface of the virus, the older surface protein could have been recognised by the immune system but the new protein will not. Thereby slipping under the notice of the immune system.

Now are all mutations beneficial?

No, most mutations are neutral, they do not change the fitness of the virus in that particular environment for example; a single nucleotide change in a non coding region or a substitution mutation that codes for the same or similar type of amino acid.

Some are even harmful for the virus if there is an insertion mutation that causes a missense or a frameshift. Therby changing the codons of the entire protein. Effectively losing an entire protein.

What mutation would make a virus more harmful.

• The surface binding proteins might become more specific to bind to their target cell
• The replication rate might increase, leading to more viral load
• Like mentioned above, mutations might enable the virus to evade the immune system.