PCC Virus, Viroids, & Prions Study Guide

Name: 

Multiple Choice
Identify the choice that best completes the statement or answers the question.

The outer protein coat of a virus is called a

a.	DNA core.	c.	bacteriophage.
b.	capsid.	d.	tail sheath.

All viruses are made of proteins and

a.	nucleic acids.	c.	bacteriophages.
b.	prophages.	d.	endospores.

A viral capsid functions to

a.	bind the virus to the surface of a host cell.
b.	transcribe viral genes.
c.	force a host cell to make copies of the virus.
d.	destroy a host cell.

The instructions for making new copies of a virus are

a.	a part of a virus’s capsid.
b.	coded in surface proteins attached to the protein coat.
c.	coded in either RNA or DNA.
d.	found only in bacteriophages.

What is the basic structure of a virus?

a.	DNA or RNA surrounded by a protein coat
b.	a capsid surrounded by a protein coat
c.	a tail sheath surrounded by tail fibers
d.	a tiny cell surrounded by a cell wall

Viruses

a.	are all about the same size.
b.	vary greatly in size and structure.
c.	rarely contain DNA or RNA.
d.	can be seen with a basic compound light microscope.

Which of the following characteristics of living things is NOT true about viruses?

a.	contain genetic material	c.	obtain and use energy
b.	evolve over time	d.	able to reproduce

A lytic infection concludes with the

a.	embedding of viral DNA into the host cell’s DNA.
b.	production of a prophage.
c.	bursting of the host cell.
d.	production of messenger RNA.

A prophage is made of

a.	bacteriophages.	c.	capsid proteins.
b.	carbohydrates.	d.	viral DNA.

Bacteriophages infect

a.	other viruses.	c.	any available host cell.
b.	bacteria only.	d.	cells undergoing the lytic cycle.

Unlike lytic viruses, lysogenic viruses do NOT

a.	inject their genetic material into the host cell.
b.	enter the lytic cycle.
c.	lyse the host cell right away.
d.	infect host cells.

During a lytic infection, the host cell is

a.	destroyed.	c.	copied many times over.
b.	prepared for the lysogenic cycle.	d.	all of the above

Which of the following is NOT a viral disease?

a.	botulism	c.	measles
b.	AIDS	d.	polio

Viral diseases can be

a.	treated with antibiotics and prevented with vaccines.
b.	treated with vaccines and prevented with antibiotics.
c.	prevented with antibiotics but not treated with vaccines.
d.	prevented with vaccines but not treated with antibiotics.

Plant viruses have a difficult time entering the cells they infect partly because

a.	plant viruses are weaker than animal viruses.
b.	plant cells have tough cell walls.
c.	many plant viruses are spread by insects.
d.	plant viruses do not have a protein coat.

Viruses cause disease by

a.	producing toxins that harm the body.
b.	reproducing independently inside the body.
c.	forming endospores in the body.
d.	disrupting the body’s normal equilibrium.

Prions differ from viruses because

a.	prions do not cause disease.	c.	prions only infect plant cells.
b.	prions contain no DNA or RNA.	d.	prions do not contain any protein.

We know viruses are not alive because they

a.	are made of cells.	c.	they are autotrophic.
b.	make prions rather than proteins.	d.	they are not made of cells.

The study of viruses is a part of biology because viruses

a.	belong to the domain Archaea.	c.	are living organisms.
b.	are about to become extinct.	d.	are active inside living cells.

A typical virus consists of a

a.	protein coat and a cytoplasm core.
b.	carbohydrate coat and a nucleic acid core.
c.	protein coat and a nucleic acid core.
d.	polysaccharide coat and a nucleic acid core.

Biologists now know that viruses

a.	are the smallest organisms.
b.	consist of a protein surrounded by a nucleic acid coat.
c.	contain RNA or DNA in a protein coat.
d.	all form the same crystalline shape.

Refer to the illustration above. Which structure represents protein?

a.	structure B	c.	structure D
b.	structure A	d.	structure E

The function of a bacteriophage’s tail and tail fibers is to inject

a.	viral protein into the host cell.	c.	glycoproteins into the host cell.
b.	viral enzymes into the host cell.	d.	viral DNA into the host cell.

The capsid of a virus is the

a.	protective outer coat.	c.	nucleus.
b.	cell membrane.	d.	cell wall and membrane complex.

A provirus is part of a virus’s

a.	lytic cycle.	c.	infection cycle.
b.	conjugation cycle.	d.	lysogenic cycle.

How is a lytic cycle different from a lysogenic cycle?

a.	The host cell is destroyed in a lysogenic cycle.
b.	The host cell is destroyed in a lytic cycle.
c.	A provirus is formed during a lytic cycle.
d.	A lytic cycle releases temperate viruses.

A virulent virus is one that

a.	has only DNA.
b.	has only RNA.
c.	reproduces only with a lysogenic cycle.
d.	reproduces only with a lytic cycle.

In a lytic cycle, viral genetic material

a.	remains separate from the host cell’s DNA.
b.	becomes part of the host cell’s DNA.
c.	becomes a provirus.
d.	remains in the host cell permanently.

The cycle of viral infection, replication, and cell destruction is called the virus’s

a.	lysogenic cycle.	c.	lytic cycle.
b.	metabolic cycle.	d.	provirus cycle.

Viroids are

a.	much smaller than viruses.	c.	misshapen proteins.
b.	much larger than viruses.	d.	found in the brain.

Prions

a.	always have a capsid.	c.	change the shape of normal proteins.
b.	cause abnormal growth in plants.	d.	are made of RNA.