Exam 2-chp 5&6-micro

The primary function of viral cultivation is

All choices are correct

The primary purpose of viral cultivation is ________.

All of the choices are correct

Host cells of viruses include ________.

All of the choices are correct.

Which of the following is a type of cytopathic effect?

All of the choices are correct.

Which of the following will not support viral cultivation

All of the choices will support viral cultivation

Choose the primary reason why it is more difficult to design antiviral drugs than antibacterial drugs.

Antiviral drugs often must target host cell functions which results in side effects in the host.

Reverse trascriptase synthesizes

DNA from RNA

Choose the term that describes a virus that has a membranous outer covering over its capsid, partially derived from a host cell.

Enveloped virus

Choose the statement that indicates how cytopathic effects are detected.

Examine infected cells with a microscope

Choose the number that best estimates the annual number of human viral infections worldwide

It is nearly impossible to measure this number accurately

Choose the number that best estimates the annual number of human viral infections worldwide.

It is nearly impossible to measure this number accurately.

Choose the statement that best describes the role of viral surface proteins or spikes.

Provide means of attachment to host cell surface

Choose the statement that best describes the role of viral surface proteins or spikes

Provide means of attachment to host cells surface

What is the rationale for providing intravenous fluids and oxygen support for this patient?

These measures are supportive therapies while the disease runs its course

Which of the following is not true regarding the structure and function of viral spikes

They are coded for by the host genome

Which of the following is not true regarding the structure and function of viral spikes?

They are coded for by the host genome

Choose the statement that correctly explains why viruses are described as "filterable."

Viruses are able to pass through a filter because of their small size.

All of the following pertain to virus envelopes except ________.

are located between the capsid and nucleic acid

Viruses that infect bacteria are specifically called

bacteriophages

Viruses

cannot be seen in a light microscope

A(n) _______ is the protein shell around the nucleic acid core of a virus.

capsid

Helical and icosahedral are terms used to describe the shapes of a virus ______.

capsid

Virus capsids are made from subunits called

capsomeres

Virus capsids are made from subunits called ______.

capsomeres

Persistent viruses that can reactivate periodically are _____.

chronic latent viruses

Viral genetic studies, vaccine development and clinical identification would not be possible without the ability to

culture viruses in vivo and in vitro

Viral genetic studies, vaccine development and clinical identification would not be possible without the ability to ________.

culture viruses in vivo and in vitro

A patient undergoing chemotherapy for cancer develops an infection with cytomegalovirus, conclusively diagnosed by the presence of "owl's eye" viral nuclear inclusions in a liver biopsy. This is an example of a(n) ________.

cytopathic effect by cytomegalovirus

Which of the following is not a characteristic of a transformed cell

decreased growth rate

An ideal antiviral drug would be one that ________.

disrupted an integral viral process while causing little damage to the host cell

The core of every virus particle always contains

either DNA or RNA

The core of every virus particle always contains _____.

either DNA or RNA

Which of the following is not associated with every virus?

envelope

During lysogeny, an inactive prophage state occurs when the viral DNA is inserted into the

host DNA

Viruses attach to their host via

host glycoproteins

Viruses attach to their hosts via ________.

host glycoproteins

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n) _______ capsid.

icosahedral

The polio vaccine currently used in the United States, the Salk vaccine, consists of polioviruses that have been treated with chemicals so that they can no longer reproduce within host cells and thus cannot establish an infection. They are referred to as _______, rather than dead, viruses.

inactive

The event that occurs in bacteriophage multiplication that does not occur in animal virus replication is ________.

injection of only the viral nucleic acid into the host cell

The envelope of enveloped viruses ________.

is obtained by viral budding or exocytosis

Respiratory syncytial virus (RSV) is a common respiratory virus causes mild cold-like symptoms in most individuals, but can be more serious in infants and the elderly, RSV is so-named because

it causes the fusion of damaged host cells forming a large, multinucleated cell

Respiratory syncytial virus (RSV) is a common respiratory virus that causes mild cold-like symptoms in most individuals, but can be more serious in infants and the elderly. RSV is so-named because ________.

it causes the fusion of damaged host cells, forming a large, multinucleated cell

Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called _____.

latent

New, nonenveloped virus release occurs by

lysis

New, nonenveloped virus release occurs by _____.

lysis

Viruses have all the following except ________.

metabolism

A naked virus has only a(n) _____.

nucleocapsid

HPV can cause cellular changes that lead to the development of cervical cancer. The virus is said to cause transformation as it changes the growth rate and properties of the host cells. Because of this, HPV can be referred to as a(n) ________ virus.

oncogenic

Mammalian viruses capable of starting tumors are _____.

oncoviruses

When growing in cell cultures, viral infection may be indicated by a clear well-defined patch where host cells have been lysed. This patch of destroyed cells is known as a _________.

plaque

Viruses with _______ -sense RNA contain the correct message for translation, while viruses with _______ -sense RNA must first be converted into a correct message.

positive; negative

Infectious protein particles are called _______.

prions

Two noncellular agents, smaller than viruses, are the infectious proteins called _______ and the infectious RNA strands called ________.

prions; viroids

Viral spikes

protrude from the envelope

Viruses acquire envelopes around their nucleocapsids during _____.

release

What structures are used by bacteriophages to attach to host cell receptors?

tail fibers

What type of phage enters an inactive prophage stage

tempature

You are running an experiment in calf serum, which cannot be autoclaved because proteins essential to your protocol will be denatured. You decide to filter sterlize the serum since the 0.22um filter is small enough to block any bacteria that may contaminate your tissue culture. The success of this procedure hinges on the fact that

the presence of viruses in your serum is inconsequential to your experiment

Viral tissue specificities are called _____.

tropisms

Lysogeny refers to

viral genome inserting into bacterial host chromosome

Infectious naked strands of RNA that affect plants are called _____.

viroids

The development of antiviral drug therapy is difficult because ________.

viruses are obligate intracellular parasites so the host cell can be harmed by the drug

Rather than to argue that a virus is "alive," it is preferred to say a virus is _______.

active

Which of the following occurs during assembly of an enveloped virus

A nucleocapsid is formed and viral spikes insert in host cell membrane

Which of the following occurs during assembly of an enveloped virus?

A nucleocapsid is formed and viral spikes insert in host cell membrane.

Creutzfeldt-Jacob disease is

a spongiform encephalopathy of humans