Microbio Ch.6 quiz

Please order the following choices to show the proper sequence for bacteriophage multiplication from the first step to the last step.

1. Adsorption 2. Penetration 3. Synthesis 4. Assembly 5. Release

Please match the statement to the term that it most accurately describes to test your understanding of the detection of viral infections.

1. Polymerase chain reaction: amplification of viral nucleic acid from a patient sample 2. Cell culture, embryo, animals: takes a long time to get diagnosis 3. Rapid tests: detect virus or cytopathic effects in cells or tissue 4. Screening: detection via antibodies in the patients blood.

Rank the following viruses from smallest to largest.

1. Yellow Fever 2. Phage T2 3. Influenza 4. Herpes 5. Poxvirus 6. Megavirus

The use of antibiotics is an effective treatment for viral infections.

False

Viral replication follows essentially the same steps as replication of a prokaryotic cell.

False

Viruses are routinely cultured in order to diagnose an infection.

False

Clear, defined patches in a monolayer of cells infected with a virus are called __________, which are essentially a cytopathic effect.

Plaques

__________ are the only active biological agents lacking any nucleic acid (DNA or RNA).

Prions

The hepadnavirus family is so named because viruses within the family infect the liver and possess DNA as their genetic material.

True

Which of the following does NOT represent an event in bacteriophage multiplication?

Uncoating of the nucleic acid in cytoplasm

Fully formed viral particles capable of establishing infection in a new host are called __________.

Virion

The capsid of a viral particle is composed of identical proteins called __________. Rod-shaped capsids are called __________, while polygon-shaped capsids are called __________.

capsomers; helical; icosahedral

Together, the capsid and the nucleic acid are referred to as the __________.

nucleocapsid

Please match the type of capsid to the statement that most accurately describes it.

1. Helical: capsid with rod-shaped capsomers that bind together to resemble a bracelet 2. Icosahedral: three dimensional, 20-sided capsid with twelve evenly-spaced corners

__________ viruses can infect host cells and later lead to cancer.

oncogenic

Please match the viral culture method with the statement that most accurately describes it to test your understanding of the various methods for growing viruses.

1. Cell culture: available for viruses with specific host ranges 2. Bird embryos: self-contained until unit with its own sterile environment and nourishment 3. Live animals: allows for viral effects on the whole organism to be observed

Please match the statement to the term that it most accurately describes to test your understanding of lysogeny, prophage, and lysogenic induction and conversion.

1. Lysogeny: condition in which the host chromosome carries bacteriophage DNA 2. Prophage: stage in which the viral DNA is incorporated into the bacterial DNA 3. Lysogenic induction: activation of prophage in lysogenic cell to begin viral replication 4. Lysogenic conversion: occurs when a bacterium acquires genes and characteristics from its temperate phage

Regarding replication of an enveloped animal virus, match the stage of replication with its definition.

1. release: viruses bud off from the host cell membrane 2. penetration: virus is engulfed in a vesicle or endosome and transported internally 3. adsorption: virus attaches to its host cell by binding cell surface receptors 4.assembly: viral nucleic acid encased in capsid, viral proteins inserted in host cell membrane 5.uncoating: vesicle membrane and viral envelope fuse, releasing capsid into the host cytoplasm 6.synthesis:under control of viral genes, the host cell synthesizes all the components needed to assemble new viral particles

The viral-host relationship is extremely important for pathogenicity, mode of transmission, the immune response, and the human measures used to control viral infections.

True

Virus are classified into species based on whether they can reproduce to produce fertile offspring, much like plants and animals.

True

Virus-induced damage to host cells, called __________, can include changes in cell size and shape.

cytopathic effects

What data or achievement was instrumental to the initial characterization of viruses?

the discovery that infectious fluid remained infectious even when passed through a filter designed to trap bacteria

Feline leukemia virus may be lethal to cats but does not infect humans. This is a reflection of

the host range of feline leukemia virus.

The special affinity that a virus has for a particular type of tissue is called a __________.

tropisms

Which step is present in bacteriophage multiplication but not in multiplication of an animal virus?

Viral genetic material is injected into the host cell.