DNA and RNA Virus Replication Quiz

Type I: Double Stranded DNA

• Replication cycle: dsDNA replicates to dsDNA.
• mRNA synthesis: dsDNA translated to mRNA.
• Utilizes DNA-dependent DNA polymerase.
• In eukaryotes, replication occurs in the nucleus; in prokaryotes, it takes place in the cytoplasm.
• Example viruses include HPV and herpes.

Type II: Single Stranded DNA

• Replication cycle: ssDNA converts to dsDNA before returning to ssDNA.
• mRNA synthesis: ssDNA to dsDNA, then to mRNA.
• Relies on host DNA polymerase to create complementary DNA.
• In eukaryotes, processes occur in the nucleus; in prokaryotes, they occur in the cytoplasm.
• Example: Parvovirus, which can cause serious illness in dogs.

Type III: Double Stranded RNA

• Replication cycle: dsRNA transforms into ssRNA before reverting to dsRNA.
• mRNA synthesis: dsRNA directly gives rise to mRNA.
• Requires RNA-dependent RNA polymerase for replication.
• In both eukaryotes and prokaryotes, processes unfold in the cytoplasm.
• Example virus: Rotavirus, a leading cause of diarrhea in infants.

Type IV: (+) Sense Single Stranded RNA

• Replication cycle: +RNA converts to -RNA and back to +RNA.
• mRNA synthesis: +RNA functions as mRNA.
• Uses RNA-dependent RNA polymerase for replication in the cytoplasm of both eukaryotes and prokaryotes.
• The RNA genome directly serves as mRNA for protein synthesis.
• Example: Poliovirus.

Type V: (-) Sense Single Stranded RNA

• Replication cycle: -RNA converts to +RNA, then back to -RNA.
• mRNA synthesis: -RNA transcribes into mRNA.
• Requires RNA-dependent RNA polymerase for replication within the cytoplasm of both eukaryotes and prokaryotes.
• The genomic RNA does not act as mRNA directly; it is transcribed into a complementary strand.
• Example viruses include influenza and Ebola.

Type VI: (+) Sense Single Stranded RNA with Retroviruses

• Replication cycle: ssRNA is converted into dsDNA and returns to ssRNA.
• mRNA synthesis: ssRNA transcribes to dsRNA and then to mRNA.
• Utilizes reverse transcriptase (RNA-dependent DNA polymerase) for replication.
• In eukaryotes, procedures happen in the nucleus; in prokaryotes, they occur in the cytoplasm.
• Must package reverse transcriptase with the genome for infection.
• Associated with oncogenic capabilities in some retroviruses, like FeLV.
• Example: HIV.

Type VII: Gapped Double Stranded DNA

• Replication cycle: gapped dsDNA converts to dsDNA, then to +RNA and -DNA before reverting to gapped dsDNA.
• mRNA synthesis: gapped dsDNA transcribes into dsDNA and then to mRNA.
• Relies on multiple polymerases: DNA-dependent DNA polymerase, DNA-dependent RNA polymerase, and RNA-dependent DNA polymerase.
• Employs reverse transcriptase during replication.
• Example: Hepatitis B virus.

Test your knowledge on the replication cycles of various types of viruses, including double-stranded and single-stranded DNA and RNA viruses. This quiz covers key concepts such as replication, mRNA synthesis, and examples of viral illnesses. Perfect for biology students focusing on virology.