DNA and RNA Virus Replication Quiz

Study Notes

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.

Description

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.