Based on the sense or polarity of the genome, single stranded RNA viruses are of two types.
Differences between Positive sense RNA Viruses and Negative sense ss RNA Viruses
1. Positive Sense RNA viruses (+ssRNA virus) or PSV
2. Negative Sense ss RNA viruses (-ssRNA virus) or NSV
Positive sense RNA viruses (PSV)
Negative sense ss RNA viruses (NSV)
Genetic Material is positive sense ssRNA
Genetic Material is Negative sense ssRNA
Virus with +ssRNA genome can be translated directly to make viral proteins  by host ribosome
Virus with -ssRNA genome cannot be translated directly to make viral proteins.
‘translation ready genome’
Not ‘translational ready genome’
Viral genome acts like cellular mRNA. ssRNA has 5’cap and poly A tail for recognition by eukaryotic host ribosme.
Negative ssRNA is  complementary to mRNA

Genetic material is infectious inside the host
Genetic material is not infectious inside the host. It It should be converted to +ss RNA by viral RNA dependent RNA polymerase (RdRP) for viral protein synthesis inside host.
+ve ssRNA viruses belong to Group IV in the Baltimore classification.
-ve  sense ssRNA viruses belong to Group V in the Baltimore classification.
The genome  usually contains relatively few genes, including an RdRP.
Negative-sense single-stranded RNA viruses have complex genomic sequences, cell cycles, and mode of replication
Most common type of plant viruses and more abundant
Less abundant compared to +ve ssRNA viruses and more infectious
Examples: SARS CoV-2, Rhino viruses, Dengue virus, MERS corona virus.
Examples: Influenza virus, Ebola virus, Hanta virus, Rabies virus, Mumps virus

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