virus genome

[yui_96]

"After infection of a cell, a viral particle must transport itself to the nucleus in order to produce viral proteins. What is the likely genomic content of the virus?"
A. Double-stranded DNA
B. Double-stranded RNA
C. Positive-sense RNA
D. Negative-sense RNA

The answer given is A because only A requires the use of nuclear RNA polymerase to create mRNA that can be translated to protein. This makes sense. However, can someone explain how RNA virus doesn't need nuclear RNA polymerase? Is it because RNA virus contains RNA polymerase itself?

---

Members don't see this ad.

 

[JustinM88]

"After infection of a cell, a viral particle must transport itself to the nucleus in order to produce viral proteins. What is the likely genomic content of the virus?"
A. Double-stranded DNA
B. Double-stranded RNA
C. Positive-sense RNA
D. Negative-sense RNA

The answer given is A because only A requires the use of nuclear RNA polymerase to create mRNA that can be translated to protein. This makes sense. However, can someone explain how RNA virus doesn't need nuclear RNA polymerase? Is it because RNA virus contains RNA polymerase itself?

How RNA virus doesn't need nuclear RNA polymerase:
RNA in general doesn't need RNA Polymerase anymore...it's already been transcribed from DNA into RNA. Now, RNA DOES need a ribosome (to be translated into a protein)
Keep this order in mind:
DNA (nucleus) ---RNA Polymerase (nucleus)---> RNA (nucleus then moves to cytoplasm) ---ribosome (cytosplasm)---> Protein (cytoplasm)
^In sentence form: DNA basically always stays in the nucleus. RNA Polymerase transcribes DNA into RNA. This RNA get modified so it can leave the nucleus and enter the cytoplasm. In the cytoplasm, this RNA gets translated at a Ribosome into a Protein.

So, for that question you posted, only a DNA virus would NEED to move into the host's nucleus. RNA virus can simply stay in the cytoplasm to get translated at a ribosome.

 

[yui_96]

How RNA virus doesn't need nuclear RNA polymerase:
RNA in general doesn't need RNA Polymerase anymore...it's already been transcribed from DNA into RNA. Now, RNA DOES need a ribosome (to be translated into a protein)
Keep this order in mind:
DNA (nucleus) ---RNA Polymerase (nucleus)---> RNA (nucleus then moves to cytoplasm) ---ribosome (cytosplasm)---> Protein (cytoplasm)
^In sentence form: DNA basically always stays in the nucleus. RNA Polymerase transcribes DNA into RNA. This RNA get modified so it can leave the nucleus and enter the cytoplasm. In the cytoplasm, this RNA gets translated at a Ribosome into a Protein.

So, for that question you posted, only a DNA virus would NEED to move into the host's nucleus. RNA virus can simply stay in the cytoplasm to get translated at a ribosome.

Wow I didn't realize it's this simple. Thanks for your patience for my silly question.

 

[JustinM88]

Wow I didn't realize it's this simple. Thanks for your patience for my silly question.

Wasn't a silly question! This test is no joke so noone should feel bad for asking about any of the questions