microbiology Quiz 5 viruses

The envelope of enveloped viruses

is obtained by viral budding or exocytosis

Viral nucleic acid types include:

dsDNA ssDNA dsRNA ssRNA

Host range is limited by

type of host cell receptors on cell membrane

The process of dissolving the envelope and capsid to release the viral nucleic acid

uncoating

Reverse transcriptase synthesizes

viral DNA from RNA

Viruses that infect bacteria are called

bacteriophages

The correct sequence of events in viral multiplication is:

adsorption, penetration, uncoating, synthesis, assembly, release

Which of the following occurs during assembly?

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

In general, most DNA viruses multiply in the host cell's _____, while most RNA viruses multiply in the host cell's _____.

nucleus and cytoplasm

A prophage

is phage DNA that is integrated into bacterial DNA.

Which of the following is not a typical capsid shape?

tetrahedral (Typical capsids are: complex, helical, icosahedron, viroid)

Classification of viruses into families involves determining all the following characteristics except 1) type of nucleic acid. 2) type of capsid. 3) presence of an envelope. 4) biochemical reactions. 5) number of strands in the nucleic acid.

Biochemical reactions

Helical and icosohedral are terms used to describe the shape of a viral

Capsid

What will support viral cultivation?

Love lab animals Embryonated bird eggs Primary cell cultures Continuous cell cultures

Viruses exhibit all of the following except

Metabolism

A naked virus only has a(n) A. Capsid B. Capsomere C. Nucleocapsid D. Envelope E. Antigenic surface

Nucleocapsid

Which of the following is not associated with every virus?

envelope

Which of the following is not a characteristic of a transformed cell? 1) viral nucleic acid integrated into host DNA 2) decreased growth rate 3) alterations in chromosomes 4) changes in cell surface molecules 5) capacity to divide indefinitely

2) decreased growth rate

Diagnosis of viral infections sometimes involves analyzing the patient's blood for specific _____ that the immune system produced against the virus. A. Glycoproteins B. Antibodies C. Complement proteins D. Antigens E. None of the choices are correct

Antibodies

The bacterium that causes botulism disease is harmless until it

Contains a certain prophage DNA

Which of the following is incorrect about prophages? 1) present when the virus is in lysogeny 2) formed when viral DNA enters the bacterial chromosome 3) replicated with host DNA and passed on to progeny 4) cause lysis of host cells 5) occur when temperate phages enter host cells

4) cause lysis of host cell

One of the principal capsid shapes is a 20-sided figure with 12 evenly spaced corners referred to as a(n) _____ capsid. A. Spiked B. Complex C. Icosahedral D. Helical E. Buckeyball

Icosohedral

Viruses acquire envelopes around their nucleocapsids during

Release

Viruses

A. Cannot be seen in a light microscope They are prokaryotic, contain 70s ribosomes, and undergo binary fission

Viruses attach to their hosts via A. Host glycoproteins B. Host phospholipids C. Viral phospholipids D. Viral flagella E. All of the choices are correct

A. Host glycoproteins

Viruses:

Cannot independently perform metabolic activities

Viral capsid are made from subunits called

Capsomeres

Host cells of viruses include A. Human and other animals B. Plants and fungi C. Bacteria D. Protozoa and algae E. All of the choices are correct

E. All of the choices are correct.

Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called A. Lysogeny B. Budding C. Plaques D. Cytopathic effects E. Pocks

Plaques

Viruses with _____-sense RNA contain the correct message for translation, while viruses with _____-sense RNA must first be converted into a correct message. 1) positive; negative 2) negative; positive 3) primary; secondary 4) secondary; primary 5) intermediate; primary

Positive; negative

Viruses that cause infection resulting in alternating periods of activity with symptoms and inactivity without symptoms are called A. Latent B. Oncogenic C. Prions D. Viroids E. Delta agents

latent