In: Biology
Describe the difference between Positive Strand RNA Viruses, Negative Strand RNA Viruses, RNA Retroviruses, and DNA Viruses.
Positive strand RNA viruses are those biruses which have positive strand of the RNA as their genetic material. This RNA acts as both genetic material as well as mRNA (messenger RNA) This class of viruses are mostly pathogens such as Hepatitis C Virus, SARS, dengue virus etc.
Negative sense RNA virus: as the name suggests, these viruses have negative strand RNA as their genetic material. Unlike in the case of above viruses, these have a complex method of replication and end up supressing immunity response of the host before they replicate. These viruses are largely human pathogens like Measles, Mumps, Rabies, Influenza, Ebola etc.
Retro virus: These viruses have positive strand RNA along with Reverse Transcriptase enzyme. This enzyme helps in replication of virus. Unlike other RNA viruses, these thrive by forming DNA from the RNA using the RT enzyme and integrate into the host system. The host thus starts producing viral proteins and the virus thrives evading the immune system. Examples include HIV, Rous Sarcoma etc.
DNA Viruses are those which have DNA as their genetic material. Based on the number of strands of DNA present, they are durther classifed into ssDNA-single stranded DNA containing positive strand of DNA. Examples include: Pox, Herpes virus etc. If a virus has both the strands of DNA its called dsDNA virus- double stranded DNA virus. Famous dsDNA include HBV, Parvo viruses etc.