Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BISC 260 > Chapter 6 > Flashcards

Chapter 6 Flashcards

1
Q

(T/F) Viruses typical cellular structure like other living organisms?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

(T/F) Viruses in the extracellular state possess few, if any, active enzymes.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which is not true of viruses…

A

a.They can exist in an intracellular or extracellular phase.

B.They infect animal and plantcells only.

c.They can be observed with an electron microscope.
d.They are acellular.

e.They replicate only inside host cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following is true of viruses in the extracellular phase…

A

a.They possess many different enzymes.

d.They can reproduce independently of living cells but only at a slow rate.

C.They behave as a macromolecular complex and are no more alive than are ribosomes.

d.They possess many different enzymes and they can reproduce independently of living cells but only at a slow rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A complete virus particle is called a …

A

a.capsid.

b.nucleocapsid.

C.virion.

d.cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The nucleic acids carried by viruses usually consist of …

A

a.DNA.

b.RNA.

C.either DNA or RNA.

d.both DNA and RNA simultaneously.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following is not true of viruses…

A

a.Viruses are acellular.
b.Viruses consist of one or more molecules of DNA or RNA enclosed in a coat of protein and sometimes in other more complex layers.

c.Viruses can exist in two phases: intracellular and extracellular.

D.Viruses replicate by binary fission.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

(T/F) Viruses infecting protists, including algae, have never been detected?

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

(T/F) One way in which small viruses package more information into small genome is to use overlapping genes so that the same base sequence is read in more than one reading frame.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

(T/F) Almost all known plant viruses are RNA viruses.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Virus morphology does not include which of the following characteristics…

A

a.size

b.shape

c.presence or absence of an envelope

D.host range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

__________ are glycoprotein spikes protruding from the outer surface of the viral envelope.

A

Peplomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Icosahedral viruses are constructed from ring- or knob-shaped units called __________.

A

Capsomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Viruses that are polyhedrons with 20 sides are said to have __________ symmetry.

A

Icosahedral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

(T/F) The largest of the viruses are similar in size to some small bacteria and are large enough to be seen with a light microscope.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

(T/F) The presence or absence of an envelope is not useful in classifying viruses because any given virus may at one time have an envelope and at another time not have an envelope.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

(T/F) Viruses such as MS2 and Qß pack additional information into their genomes through the use of overlapping genes.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The simplest viruses consist of…

A

a.RNA only.

b.Protein only.

C.RNA or DNA in a protein coat.

d.RNA or DNA in a protein coat covered with lipid envelope.

e.RNA, DNA and enzymes in a protein coat with a lipid envelope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Viral capsid proteins subunits are called….

A

a.auxomers.

b.elastomers.

C.protomers.

d.viromers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In an enveloped virus, the part of the virus including the nucleic acid genome and the surrounding protein coat but not the envelope is called the…

A

a.capsid.

B.nucleocapsid.

c.matrix.

d.virion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Some complex viruses have icosahedral symmetry in the head region and helical symmetry in the tail. Overall, these viruses are said to have __________ symmetry….

A

a.bilateral

B.binal

c.complex

d.none of these

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Glycoprotein spikes protruding from the outer surface of viral envelopes function as…

A

a.toxins.

B.factors that bind to host cells.

c.cell lysis factors.

d.factors needed for site specific recombination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

A __________ genome exists as several separate, nonidentical molecules that may be packaged together or separately.
….

A

a.diploid

B.segmented

c.polyploid

d.fractionated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Many of the enzymes found in virus particles are….

A

a.required for viral attachment to host cells.

b.involved in viral entry into host cells.

C.involved in the replication of viral nucleic acid.

d.all of the choices

25
Q

Which of the following is/are not true about viral envelopes?….

A

a.The envelope proteins are virus specific.

b.The envelope lipids and carbohydrates are derived from the host.

C.They are typical lipid monolayers with embedded viralproteins.

d.The envelope proteins are virus specific and the envelope lipids and carbohydrates are derived from the host

26
Q

Viral envelopes are composed of….

A

a.proteins.

b.lipids.

c.carbohydrates.

D.all of the choices

27
Q

Two major types of symmetry found in viruses include….

A

a. icosahedral and radial.
B.icosahedral and helical.
c.helical and radial.

d. radial and bilateral.

28
Q

The function of the viral protein coat is to….

A

a.protect the viral genetic material.

b.aid in the transfer of the viral genetic material between host cells.

c.elicit the production of protective antibodies.
D.protect the viral genetic material and aid in the transfer of the viral genetic material between host cells.

29
Q

The protein coat surrounding the viral genome is called the
….

A

a.capsule.

B.capsid.

c.matrix.

d.envelope.

30
Q

Which of the following is most true of a viral DNA genome?….

A

a.It uses the same four nitrogenous bases found in prokaryotic and eukaryotic DNA.

B.It may have the normal bases found in prokaryotic and eukaryotic DNA, or it may have one or more unusual bases.

c.It is usually composed of unusual bases unique to viruses.

d.Viruses do not use DNA for their genome.

31
Q

Virion size ranges from….

A

a.1–40 nm.

B.10–400 nm.

c.600– 1,000 nm.

d.1,000–10,000 nm.

32
Q

Viral capsids are generally constructed without any outside aid once the subunits have been synthesized. This process is called….

A

a.facilitated assembly.


B.self-assembly.
c.spontaneous maturation.
d.self-maturation.

33
Q

In which of the following stages of the viral infectious cycle do enveloped viruses usually acquire their envelopes?…


A

a.penetration

b.component biosynthesis
c.assembly

D.release

34
Q

Most enveloped viruses use the host __________ membrane as their envelope source….

A

A.plasma

b.nuclear

c.mitochondrial

d.none of these

35
Q

Poliovirus receptors are found…

A

a.in cells of all tissues.

b.in spinal cord anterior horn cells only.

C.in nasopharynx, gut, and spinal cord anterior horn cells.
d.in gut cells only.

36
Q

Nonenveloped viruses most often gain access to eukaryotic host cells by…

A

a. fusion with the host cell plasma membrane followed by entrance of the nucleocapsid into the cytoplasm.
B.endocytosis.

c. pinocytosis.

d. nucleic acid injection through the plasma membrane.

37
Q

Which of the following represent(s) the way(s) in which enveloped viruses acquire their envelopes?
….

A

a.Budding through the plasma membrane.

b.Budding through internal cellular membranes.

c.Viral enzymes are responsible for production of the envelope.

D.For some viruses, a is correct; for other viruses, b is correct.

38
Q

(T/F) Virus receptors are often not distributed uniformly over the surface of host cells, but are instead concentrated in lipid rafts.

A

True

39
Q

(T/F) Enveloped viruses may enter their host cells by fusion of their envelope with the cytoplasmic membrane, thereby depositing their nucleocapsid within the cell.

A

True

40
Q

(T/F) Enveloped viruses may enter their host cells by engulfment within coated vesicles (endocytosis).


A

True

41
Q

Some viruses cause abnormal growth of cells rather than destruction. This is called __________.


A

Transformation

42
Q

Human cancer causing viruses most often have a ___________ genome…..

A

a.ssDNA

B.dsDNA

c.ssRNA

d.dsRNA

43
Q

Adult T-cell leukemia is thought to be caused by….

A

a.herpesviruses.

B.retroviruses.

c.parvoviruses.
d.picornaviruses.

44
Q

Genes whose expression (or abnormal expression) causes cancer are called….

A

a.cancer genes.

b.progenies.

C.oncogenes.

d.carcinogens.

45
Q

Which of the following has been associated with a form of liver cancer?….

A

a. Human papilloma virus.
B.Hepatitis B virus.

c. Human T-cell lymphotropic virus.

d. Hepatitis A virus.

46
Q

Microscopic or macroscopic degenerative changes or abnormalities in infected host cells and tissues are called __________ __________.

A

cytopathic effects

47
Q

(T/F) In a plaque assay, the number of infectious virions is usually identical tothe number of virus particles present.


A

False

48
Q

Animal viruses have been cultivated in
….

A

a.suitable host animals.
b.embryonated eggs.

c.tissue cultures (monolayers of animal cells).

D.all of the choices

49
Q

Which of the following can be used to cultivate plant viruses?…

A

a.Cultures of separated plant cells.

b.Whole plants.

c.Plant protoplast cultures.
D.All of these can be used to cultivate plant viruses.

50
Q

Hemagglutination is
….

A

A.the clumping together of red blood cells in the presence of a viral suspension.


b. the binding of iron in the process of a viral suspension.
c.the clumping together of infected cells in the presence of a viral suspension.
d. none of the choices

51
Q

(T/F) Like bacteria and eukaryotic microorganisms, most viruses can be cultured using artificial media.

A

False

52
Q

(T/F) Bacterial viruses are so named because they have prokaryotic cell structures similar to their bacterial hosts.


A

False

53
Q

Localized areas of destruction occurring on plants that have been infected by a virus are referred to as __________ lesions.


A

necrotic

54
Q

Which of the following is not a mechanism by which viruses cause cancer?….

A

a.They carry a cancer-causing gene into the cell.

b.They encode proteins that bind to and inactivate host cell proteins known as tumor suppressor proteins.

C.They produce defective interfering particles.

d.An expression of viral proteins results in abnormal expression of genes that regulate cell growth and reproduction.

55
Q

Which of the following is not true regarding the human hepatitis D virusoid?….

A

a.Its genome is a circular, single-stranded RNA molecule.

b.It needs a helper virus to infect host cells.

c.It produces one protein called the delta antigen.

D.All of the statements are true.

56
Q

Viroids are of economic significance because they cause disease in…

A

A.plants.


b. animals.

c. humans.

d. all of the choices

57
Q

Viroids are:….

A

a.proteins that may infect man and other animals causing spongiform encephalopathy.

b.a class of so-called slow viruses.

c.a new class of small single stranded DNA viruses that infect some animals.

D.short infectious single stranded RNAs that can infect some plants.

58
Q

(T/F) Prions consist of proteins and have no apparent nucleic acid genome.

A

True

BISC 260 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions