Viral Evolution and the RNA to DNA Transition Quiz

Play an AI-generated podcast conversation about this lesson

Which step comes after attachment in the virus entry process?

Penetration

Transport

Uncoating

Entry (correct)

How do enveloped viruses primarily enter the host cell?

Formation of syncytia

Fusion and fusion of the envelope with the plasma membrane (correct)

Passage of viral genome through a channel in the membrane

Receptor-mediated endocytosis followed by fusion/fission with an endosome

What is the primary entry mechanism for non-enveloped viruses?

Receptor mediated endocytosis followed by rupture of endosomal membrane (correct)

Fusion with the plasma membrane

Formation of syncytia

Passage of viral genome through a channel in the membrane

What is the purpose of virological synapses in cell-to-cell transmission?

Allow passage of enveloped viruses from one cell to another Signup and view all the answers

What is the first step for virus entry into the host cell?

Attachment Signup and view all the answers

What do attachment factors/adhesion receptors do?

Involved in binding of virion to cell but not uptake Signup and view all the answers

What triggers macropinocytosis in virus entry?

Exploiting cell signaling Signup and view all the answers

What is the purpose of low pH in virus entry?

Triggers passage from endosomes to the cytosol Signup and view all the answers

What is the role of entry receptors in virus entry?

Play an active role in conformational changes, cell signaling, endocytosis, etc. Signup and view all the answers

What is the primary mechanism for enveloped viruses to enter the host cell?

Fusion of envelope with cell membrane Signup and view all the answers

What is the purpose of syncytia formation in virus transmission?

Results from fusion of infected and uninfected cells Signup and view all the answers

What is the purpose of receptor-mediated endocytosis in virus entry?

Viruses enter the cell Signup and view all the answers

What is a key characteristic of viroids and RNA viruses?

They may have originated in the RNA world Signup and view all the answers

What is the main function of the mission of viruses?

To transport the viral genome from an infected cell to uninfected cell Signup and view all the answers

What is the potential origin of small and medium-sized DNA viruses?

Independently replicating genetic elements in cells Signup and view all the answers

What is the role of reverse transcriptase in the transition to the DNA-based world?

To make DNA copies of RNA Signup and view all the answers

What is the likely fate of genes that overlap with cellular genes in large DNA viruses?

They were lost due to similar functions Signup and view all the answers

What is the main requirement for viruses to replicate?

They need host cells Signup and view all the answers

What is the key difference between DNA and RNA in the context of stability?

DNA is much more stable than RNA Signup and view all the answers

What is the primary function of viral proteins in large DNA viruses?

Stimulate DNA replication enzymes in the host Signup and view all the answers

What is the significance of the production of deoxyribonucleotides from ribonucleotides in the transition to the DNA-based world?

It allowed for the creation of DNA copies of RNA Signup and view all the answers

What is the primary role of viruses in evading host defenses?

To 'evade' host cell defense barriers Signup and view all the answers

What is the likely origin of large DNA viruses?

They could have evolved from cellular forms Signup and view all the answers