Virology Lecture 2: Virus Classification and Replication

Virus attachment is the binding of the virus to the host ______.

Rhinovirus binds a protein known as ______ 1 (ICAM-1).

Influenza A virus strains bind to the ______ acid sugars found at the ends of cellular carbohydrate chains.

HIV initially binds to a protein known as ______ on the surface of T lymphocytes with one of two coreceptor proteins.

The Baltimore classification system categorizes viruses based on the type of ______ acid genome and replication strategy of the virus.

Poliovirus binds to the ______ receptor (PVR) CD155.

Measles virus binds to ______, CD150.

Positive-strand RNA is able to be immediately translated into ______.

Dengue virus binds to ______.

Viruses are only classified using ______, family, genus, and species.

The ______ of a virus is generally the “common name” of the virus.

Most types of viruses use ______-mediated endocytosis to enter the cell.

The suffix -virales is used in the ______ of viruses.

Negative-strand RNA is not translatable into ______; it first has to be transcribed into positive-strand RNA.

The genus of a virus ends in the suffix -______.

The family of a virus ends in the suffix -______.

The virus's genome acts as the instructions for the synthesis of virus ______.

The replication strategy of a virus is generally dependent upon the type of ______ acid genome it contains.

Viruses with ______ genomes have similar nucleic acid to living organisms and often use the enzymes and proteins that the cell normally uses.

The Baltimore classification system categorizes the viruses into seven classes based upon their type of ______.

The ______ polymerases are used by viruses with dsDNA genomes.

The ______ viruses are classified into Class I according to the Baltimore classification system.

The ______ viruses are classified into Class IV according to the Baltimore classification system.

The ______ virus is an example of a virus that reverse transcribes.

So all dsDNA viruses that infect humans enter the nucleus of the cell, while ______ genomes do not.

During replication, the ssDNA genome enters the nucleus of the host cell, where the ssDNA is converted to dsDNA by ______ polymerase.

DsRNA viruses contain an ______ that is carried into the cell within the virion.

The genomes of +ssRNA viruses are infectious, since positive-sense RNA is able to be directly translated by ______.

−ssRNA viruses are not infectious and must be transcribed into ______ before translation can occur.

Retroviruses are viruses that reverse transcribe an RNA genome into ______.

RNA polymerase II transcribes an RNA pregenome that is reverse transcribed, after being packaged into the capsid, into the rcDNA genome in the ______ of the cell.

New strains of virus can occur when two different strains infect one ______.

Recombination occurs when the genome of an RNA virus is being replicated and the RdRp jumps from the template of one strain to the template of the other strain, creating a hybrid ______.

Reassortment occurs when the genome segments of ______ viruses are mixed while being packaged into new capsids.

Viruses components must be collected at a particular site of the cell and undergo assembly to form an immature ______ particle.

Most nonenveloped DNA viruses assemble their nucleocapsid in the ______, since that is the site of genome replication.

Viruses with envelopes derived from the plasma membrane usually assemble at the ______.

Maturation refers to the final changes within an immature ______.

The HA1 portion binds the cell surface ______, the HA2 portion is what fuses the viral envelope to the endosomal membrane to release the virus into the cytoplasm.

Nonenveloped viruses can also exit the cell via ______.