The direction of genetic information transfer in a retrovirus (such as HIV) is

Question

A.  DNA to mRNA to protein.
B.  RNA to DNA to mRNA to protein.
C.  DNA to protein.
D.  RNA to mRNA to protein.
E.  RNA to protein.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
 
Gather Content
· What do you already know about the HIV infection cycle?

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

  Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

B.  RNA to DNA to mRNA to protein.


Clarify Question
· What is the key concept addressed by the question?
        o This question addresses the HIV infection cycle.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
 
Gather Content
· What do you already know about the HIV infection cycle?
        o HIV is a retrovirus, so the RNA genome is copied into DNA, then back into RNA again.
        o Inside the host cell, the HIV particle sheds its protective coat.  Reverse transcriptase synthesizes a double strand of DNA complementary to the virus RNA, often making mistakes and introducing new mutations.
        o This double-stranded DNA then enters the nucleus  and is incorporated into the host cell’s DNA. After a period of dormancy the HIV provirus directs the host cell’s machinery to produce many copies of the virus.

  Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o HIV is a retrovirus. The particles carry RNA, which is reverse transcribed into DNA, then later transcribed into mRNA and translated into protein.

  Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that retroviruses carry RNA in their particles, which are reverse transcribed into DNA, then later transcribed and translated?