chapter 6 smartbook

assembly/maturation

During the ... step in the viral multiplication cycle, the genetic material is packaged into capsids to make virions

lysis

During the lytic cycle of bacteriophages, the ultimate destiny of a phage-infected bacterial cell is which of the following?

transduction

Genes for toxin production and drug resistance can be transferred by bacteriophages between bacteria during which process?

- Engulfment/phagocytosis of the virus - Fusion of the viral envelope and the cell membrane

Identify all the methods that a virus can use to gain entry into an animal cell

- ssDNA - dsDNA - ssRNA

Identify all the types of nucleic acid genomes which have been discovered carried by various bacteriophages.

- Bacterial cells - Animal cells - Human cells

Identify the different environments in which some viruses can replicate

No, because the virus relies on host enzymes and machinery.

If a virus were to infect a host cell but the cell's enzymes had been denatured, could the virus still replicate?

helical

Influenza, measles, and rabies are viruses that have a(n) ... shaped capsid

toxins

It is possible for a lysogenized bacteria to produce which of the following that are harmful to people?

Integration of the viral genome into the host chromosome

Lysogeny is best described as which of the following?

Envelope

Many animal viruses will acquire which of the following from the host cell's membrane?

DNA

Most ... viruses will assemble their virions within the host cell's nucleus

Animal viruses

Most enveloped viruses are which of the following?

Lysis

Naked viruses are released from animal cells by which of the following methods?

transduction

Phages can serve as transporters of bacterial genes from one bacterium to another in a a process called ...

icosahedron

Poliovirus and adenovirus have a capsid arranged in a symmetrical polygon structure called a(n) ...

Latency

Some animal viruses can insert their genomes into a host cell's DNA. This process is called which of the following?

host

The ... range defines the limitations of the type of cell that a virus can invade

CPE

The acronym for cytopathic effects is ...

nerve

The herpes zoster virus goes into latency in ... cells

spikes

The peplomers or ... of a virus are protruding glycoproteins, responsible for binding to a host cell

uncoating

The process of ... occurs when viruses lose their envelope during penetration into a host cell or when the envelope/capsid is are dissolved within a vacuole

DNA only

The smallpox virus contains which of the following nucleic acid(s)?

genome

The total nucleic acid content of a virus can be referred to as the viral ...

complex

The word ... is used to describe viruses which have a non-icosahedral or non-helical arrangement of capsomer proteins

nucleocaspid

Together the viral capsid and nucleic core is referred to as the ...

liver; salivary

Tropisms are tissue specificities of animal viruses for certain body cells, e.g., the hepatitis B virus targets the ... and the mumps virus targets ... glands

true: Temperate phages do not all immediately go into the lytic cycle

True or false: It is possible for a bacterial cell infected with a temperate phage to replicate before induction occurs

true

True or false: The number of viruses released by an infected host cell can vary in the thousands.

budding; lysis

Two ways in which newly assembled viruses are released from host cells are through ... or exocytosis by enveloped viruses, and through ... (rupture) by naked viruses

Be converted into a positive-strand of RNA

Viruses with negative-strand RNA molecules must first be converted to which of the following in the process of replication.

positive

Viruses with single-stranded RNA genomes that can be directly translated into proteins are called ...-strand RNA viruses.

negative

Viruses with single-stranded RNA genomes that have to be converted to the the "other strand of RNA" before it can be translated into proteins are called ...--strand RNA viruses

Active

What are viruses called when they are infectious?

Viruses must have a host cell

What does "obligate" mean in regard to viruses?

- Protection - Attachment

What functions do capsid proteins perform for naked viruses?

They are preformed viral proteins.

What is common to replicase and reverse transcriptase?

induction

What term is used to define the process of a prophage being activated and entering into the lytic cycle?

Icosahedral

What term is used to describe the capsid of a virus which has 20 equally spaced panels of capsomers forming a symmetrical structure?

spikes

What term is used to describe the viral proteins which protrude from the envelope and aid in attachment to host receptors?

Bacteriophages

What term is used to describe viruses which infect bacteria?

Adsorption

What term is used to describe when a virus initially "sticks" to the host cell?

Lysogenic conversion

When a bacterium acquires a new trait from a temperate phage, which of the following has occurred?

Inactive

When viruses are exposed to compounds or UV-light which make them non-infectious what are they called?

nucleus

Where are most DNA viruses replicated and assembled within the host?

Cytoplasm

Where are most RNA viruses replicated and assembled within the host?

Spiral

Which best describes the shape of a helical virus?

All have undergone lysogenic convergence

Which describes the bacterial causative agents of cholera, botulism, and diphtheria?

Cell disease

Which is a simple translation of cytopathic?

Mitochondrion

Which is not a host component from which viruses bud?

- React to environmental factors - Replicate independently - Metabolize food - Maintain homeostasis

Which of the following activities are not characteristics of viruses?

- Acellular - Obligate intracellular parasites - infects very specific cell types

Which of the following characteristics are correct for viruses?

- Flexible tail - Polyhedral capsid head - Complex

Which of the following describes bacteriophages?

assembly

Which of the following describes the process of various viral "parts" coming together to produce complete virions?

Smaller than 0.2 micrometers

Which of the following describes the size of most viruses?

Either single or double-stranded

Which of the following describes viral DNA genomes?

Either single-stranded or double-stranded

Which of the following describes viral RNA genomes?

Non-living, infectious agent

Which of the following describes viruses?

virion

Which of the following is a fully formed virus that is able to establish an infection in a host cell?

Poxviruses

Which of the following is a group of complex viruses that lack a typical capsid and are covered by a dense layer of lipoproteins and fibrils?

Syncytium

Which of the following is a multinucleated mass of cells due to the cytopathic effect of viral infection?

Polymerase

Which of the following is a preformed viral protein that synthesizes DNA and RNA?

host range

Which of the following is a term used to describe the different host cells which a virus can infect?

Capsomer

Which of the following is the monomeric unit for a viral capsid?

Prophage

Which of the following is used to describe the phage DNA that is latently incorporated into the bacterial host genome?

- Nucleic acid - Capsid - Acellular

Which of the following relate to all viruses?

persistent

Which of the following terms describes viruses in the carrier state within the host cells?

Reverse transcriptase

Which preformed enzyme is involved in the synthesis of DNA from RNA in retroviruses, such as HIV?

Capsid

Which structure immediately encloses viral nucleic acid?

Ultramicroscopic

Which term best describes viruses?

Transformation

Which term describes the integration of an oncogenic virus into mammalian DNA, changing the characteristics of the host cell?

Uncoating

Which term describes the process of a virus losing its capsid and exposing viral nucleic acids to the immediate environment?

tropisms

Which term describes the tissue specificities of animal viruses for certain body cells?

Envelope

Which term is used to describe the phospholipid bilayer found surrounding the capsid of some viruses?

Lysis

Which term refers to the physical rupture of a cell?

complex

Which type of capsids are composed of multiple protein types and nonsymmetrical shapes?

Viruses

Which type of microbe is considered the most abundant on earth?

Electron

Which type of microscope is usually used to examine viruses?

adsorption

Which viral stage occurs first?

inclusion

a mass of viruses or damaged organelles

oncovirus

a virus that leads to cancer

spikes

most viral .... in the capsid or envelope are composed of glycoproteins and are used to attach to cells

prophage

the persistence of bacteriophage DNA within a host chromosome

adsorption, penetration, synthesis, assembly, release

viral stages in order

Persistent infection

A cell harboring a virus that is not causing cytopathic effects is characteristic of which type of infection?

several days to weeks to years

A persistent infection could last how long in a host?

- DNA only - RNA only

A single virion could contain a genome of which of the following?

cytopathic

A syncytium is an example of a(n) ... effect of viruses

10

By one estimate, viruses outnumber bacteria by which factor?

Proteins

Capsomers are composed of which macromolecule?

Human, bacterial, or plant cells

Different viruses can infect which of the following?

temperate

A(n) ... phage is a bacteriophage that incorporates itself into the host genome as a lysogenic prophage.

naked

A(n) ... virus does not have an envelope surrounding its capsid

20-1000 nm

Animal viruses are typically what size?

bacteriophage

Any virus that specifically infects bacteria is called a(n) ...

Capsid and nucleic acid

At minimum, viruses are composed of which of the following?

lysis

Bacterial host cells undergo ... due to the splitting open and release of bacteriophages