The following questions refer to the following paragraph.
HIV's genome of RNA includes the code for reverse transcriptase (RT), an enzyme that acts early in infection to synthesize a DNA genome off of an RNA template. The HIV genome also codes for protease (PR), an enzyme that acts later in infection by cutting long viral polyproteins into smaller, functional proteins. Both RT and PR represent potential targets for antiretroviral drugs. Drugs called nucleoside analogs (NA) act against RT, whereas drugs called protease inhibitors (PI) act against PR.
-Within the body of an HIV-infected individual who is being treated with a single NA, and whose HIV particles are currently vulnerable to this NA, which of these situations can increase the virus' relative fitness?
1)mutations resulting in RTs with decreased rates of nucleotide mismatch
2)mutations resulting in RTs with increased rates of nucleotide mismatch
3)mutations resulting in RTs that have proofreading capability
A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 2 and 3

Question

Quizplus · Accepted Answer

If the RT mutations result in an increased rate of nucleotide mismatch, then the virus may develop resistance to the NA, increasing its relative fitness. Mutations resulting in RTs with decreased rates of nucleotide mismatch or with proofreading capability would actually decrease the virus' ability to mutate and develop resistance, lowering its relative fitness.

The Following Questions Refer to the Following Paragraph