Viral Structure and Basics
This term refers to an intact, complete virus particle consisting of a nucleic acid genome surrounded by a protein coat.
What is a virion?
A host cell that expresses the specific surface receptor required for virus entry is termed "susceptible," while a cell that allows all subsequent steps of viral replication is termed this.
What is permissive?
In 1796, Edward Jenner successfully vaccinated an 8-year-old boy against smallpox using fluid from cowpox lesions making this vaccine.
What is vaccinia?
The Baltimore Classification system categorizes viruses into 7 classes based on their genome type and mechanism to produce this essential molecule.
What is messenger RNA (mRNA)?
These viruses infect bacteria, releasing organic matter back into the aquatic food web via a process known as the "viral shunt".
What are bacteriophages?
These are the three primary types of capsid symmetry.
What is helical, complex, icosahedral?
Because host cells lack an enzyme capable of copying RNA from an RNA template, RNA viruses must encode or carry this specific enzyme.
What is RNA-dependent RNA polymerase (RdRp)?
These four classical criteria, established by a German physician using Bacillus anthracis, link a specific microorganism to a specific disease.
What are Koch's Postulates?
Under the Baltimore classification system, Retroviruses belong to Class VI because they use this enzyme to replicate through a DNA intermediate.
What is reverse transcriptase?
High-risk strains 16 and 18 of this sexually transmitted virus are responsible for approximately 99% of cervical cancers.
What is Human Papillomavirus (HPV)?
Viruses are measured in this unit.
What is nanometers?
Unlike eukaryotic host mRNAs, which are monocistronic and require a $5'$ cap, some viral RNAs bypass cap-dependent translation using this RNA structure.
What is an Internal Ribosome Entry Site (IRES)?
In 1892 and 1898, Dimitri Ivanovsky and Martinus Beijerinck demonstrated that the causative agent of this plant disease passed through bacteria-retaining filters.
What is Tobacco Mosaic Disease (or Tobacco Mosaic Virus / TMV)?
This ending of a virus indicates the Family of the virus discovered.
What is -viridae?
Humans act as "dead-end hosts" for this arbovirus, which is primarily cycled between mosquitoes and wild birds.
What is West Nile Virus?
Viruses that lack a surrounding lipoprotein membrane are referred to by this terms.
What is naked (or non-enveloped)?
While most DNA viruses replicate their genomes inside the host nucleus, this family of large complex DNA viruses is a notable exception that replicates in the cytoplasm.
What are Poxviruses (or Poxviridae)?
The 1952 Hershey-Chase "blender experiment" used radiolabeled phosphorus 32^P and sulfur 35^S in bacteriophages to prove this molecule is the genetic material.
What is DNA?
Human DNA is estimated to be roughly this percentage endogenous retroviral sequences.
What is 8%?
In 1981, clusters of this rare vascular tumor in young men in San Francisco and New York served as an early indicator of the emerging HIV/AIDS epidemic.
What is Kaposi's sarcoma?
Enveloped viruses acquire their lipid membrane during egress through a process where viral envelope proteins insert into host membranes and pinch off.
What is budding?
During the replication cycle of all RNA viruses, the production of this key intermediate triggers a host cellular "infection alarm".
What is double-stranded RNA (dsRNA)?
In 1955, Heinz Fraenkel-Conrat and Robley Williams demonstrated for the first time that an infectious virus could spontaneously do this in a test tube using only purified RNA and protein.
What is assemble in vitro (or self-assemble)?
These are the 4 main characteristics that factor into viruses being grouped together.
What are Nature of the nucleic acid (DNA or RNA), Symmetry of the protein shell (capsid),Presence or absence of lipid membrane (envelope), Dimensions of the virion and capsid?
This giant virus family, discovered in 2013, possesses genomes over 1 million base pairs in size, blurring the boundary between viral and parasitic cellular life.
What are Pandoraviruses (or Pandoraviridae)?