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Bio question
- Thread starter DDSCaroline
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Isn't this just that some RNA viruses have single stranded RNA and some have double-stranded? Beyond that seems like more complex than would be on the DAT; where are you seeing this btw?
Upon reading through Campbell's chapter on Viruses, I see nothing about (+/-), not sure what you mean by that. It basically says ssRNA can be used directly as mRNA. There are some other minor things about different types and classes, but I find it hard to believe the DAT would ask you to identify the class and type of RNA a specific virus has. Maybe I'm not understanding your question too well.
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In terms of virology, this is known as the Baltimore classification system.
By convention, the mRNA transcribed from the RNA or DNA viral genome is given the (+) orientation. When the viral genome's RNA or DNA has the same sense as the mRNA (RNA-5'GGAU...3' vs mRNA-5'GGAU...3'), then the virus is said to be +RNA or +DNA.
If the genome is anti-sense to the mRNA (RNA-5'CCUA...3' vs mRNA-5'GGAU...3'), then the virus is -RNA.
The dsRNA virus is +/-dsRNA because one strand of the RNA has the same sense as the mRNA, while the complementary RNA strand is anti-sense.
By convention, the mRNA transcribed from the RNA or DNA viral genome is given the (+) orientation. When the viral genome's RNA or DNA has the same sense as the mRNA (RNA-5'GGAU...3' vs mRNA-5'GGAU...3'), then the virus is said to be +RNA or +DNA.
If the genome is anti-sense to the mRNA (RNA-5'CCUA...3' vs mRNA-5'GGAU...3'), then the virus is -RNA.
The dsRNA virus is +/-dsRNA because one strand of the RNA has the same sense as the mRNA, while the complementary RNA strand is anti-sense.
