MicroBio Q's TF CH 5

Question 1

Ch 5

The genetic material found in a virion is usually what?

Answer 1

Either DNA or RNA

Question 2

Ch 5

Viral particles are composed of what?

Answer 2

DNA or RNA, a coat of protein, and layers of carbohydrates, lipids and additional proteins

Question 3

Ch 5

What is the best microscopic methods for studying viruses?

Answer 3

Electron microscopy

Question 4

Ch 5

What is the function of the viral capsid?

Answer 4

To the protect the viral genome

Question 5

Ch 5

The Tobacco mosaic virus exhibits which type of capsid symmetry?

Answer 5

Helical

Question 6

Ch 5

An example of a virus that exhibits binal symmetry is known as what?

Answer 6

Bacteriophages

Question 7

Ch 5

Viral spikes or peplomers are involved in what?

Answer 7

Attachment

Question 8

Ch 5

Which structures are associated with the influenza virus?

Answer 8

Neuraminidase enzyme, hemagglutinin protein, and glycoproteins

Question 9

Ch 5

The most common viral nucleic acid types are what?

Answer 9

dsDNA and ssRNA

Question 10

Ch 5

What is the first step in the generalized viral life cycle?

Answer 10

Attachment of virus to host cell

Question 11

Ch 5

What is viral host specificity most likely attributed to?

Answer 11

Interaction between receptors on the surface of the host cell and ligands on the surface of virions

Question 12

Ch 5

Which mechanisms do eukaryotic viruses enter host cells through?

Answer 12

Through fusion of the viral envelope with the host cell membrane, entry by endocytosis, and injection of nucleic acid

Question 13

Ch 5

Which types of viruses must carry their own replication enzymes in their nucleocapsid?

Answer 13

RNA viruses only

Question 14

Ch 5

Where does the energy that is required for bacteriophage assembly come from?

Answer 14

Host metabolic activity

Question 15

Ch 5

What is a common virion release method observed in enveloped viruses?

Answer 15

Budding

Question 16

Ch 5

What is the name of the relationship with the host cell in which the virus remains within the host without destroying it called?

Answer 16

Lysogeny

Question 17

Ch 5

What does an advantage of lysogeny to the host include?

Answer 17

Resistance to superinfection

Question 18

Ch 5

When more phage are present in the environment than there are host cells, which type of host relationship is most desirable?

Answer 18

Lysogenic preferred

Question 19

Ch 5

What are microscopic and/or macroscopic damages to host cells caused by eukaryotic viruses called?

Answer 19

Cytopathic effects

Question 20

Ch 5

What is the name for a type of viral infection in which there is a low release of virions without cell death?

Answer 20

Chronic infection

Question 21

Ch 5

What cellular genes required for normal growth, but when mutated or overexposed, cause carcinogenesis?

Answer 21

Proto-oncogenes

Question 22

Ch 5

Which of the following viruses is NOT definitely linked to causing cancer in humans?

Answer 22

Rabies virus

Question 23

Ch 5

Which methods can be used to cultivate plant viruses?

Answer 23

Grow in cultures of plant cells lacking cell walls, mechanically break leaves to expose cells to infection, or graft diseased part onto a healthy plant

Question 24

Ch 5

What can be used to determine direct counts of viral particles?

Answer 24

Epifluorescence microscopy

Question 25

# Ch 5 What is an indirect method of counting animal viruses?

Answer 25

Hemagglutination assay

Question 26

# Ch 5 The number of plaque-forming units (PFUs) is calculated from a viral plaque assay by.....?

Answer 26

Multiplying the number of plaques per volume by the dilution

Question 27

# Ch 5 What is teh dilution taht contains the number of viral cells large enough to destroy 50% of the host cells or organisms called?

Answer 27

The lethal dose

Question 28

# Ch 5 What are infectious RNAs that primarily infect plants called?

Answer 28

Viroids

Question 29

# Ch 5 What are infectious proteins responsible for bovine spongiform encephalopathy called?

Answer 29

Prions

Question 30

# Ch 5 Viruses are considered to be living organisms

Answer 30

FALSE

Question 31

# Ch 5 Scientists classify viruses based on genome structure, life cycles, morphology, and genetic relatedness

Answer 31

TRUE

Question 32

# Ch 5 Most viruses are approximately the same size as bacteria (0.2 to 2 micrometers)

Answer 32

FALSE

Question 33

# Ch 5 Hos-independent growth has never been observed in either the bacterial or archaeal viruses

Answer 33

FALSE

Question 34

# Ch 5 The size of a helical capsid is influenced by both its protomores and the nucleic acids enclosed within the capsid

Answer 34

TRUE

Question 35

# Ch 5 The icosohedral capsid maximizes efficiency and requires few genes for its coding

Answer 35

TRUE

Question 36

# Ch 5 An envelope is present in all viruses

Answer 36

FALSE

Question 37

# Ch 5 Spikes can be used to identify many types of viruses

Answer 37

TRUE

Question 38

# Ch 5 All virions lack enzymes

Answer 38

FALSE

Question 39

# Ch 5 Most DNA viruses use dsDNA as their genetic material

Answer 39

TRUE

Question 40

# Ch 5 Many RNA viruses have segmented genomes with each segment coding for a protein

Answer 40

TRUE

Question 41

# Ch 5 Viral attachment to the host cell is a random process

Answer 41

FALSE

Question 42

# Ch 5 Variation in receptors used by a virus for attachment is partly responsible for host specificity

Answer 42

TRUE

Question 43

# Ch 5 All viruses inject their nucleic acid into the cytoplasm of their host, leaving the capsid outside and attached to the cell wall

Answer 43

FALSE

Question 44

# Ch 5 Human immunodeficiency virus (HIV) enters the host cell by fusing directly with the host cell plasma membrane

Answer 44

TRUE

Question 45

# Ch 5 DNA and RNA viruses replicate using the same processes

Answer 45

FALSE

Question 46

# Ch 5 Bacteriophages are assembled in the host cytoplasm

Answer 46

TRUE

Question 47

# Ch 5 All animal viruses are assembled in the cytoplasm

Answer 47

FALSE

Question 48

# Ch 5 Many nonenveloped viruses lyse their host cells at the end of the intracellular phase

Answer 48

TRUE

Question 49

# Ch 5 When viral cells are released via budding, the host cell may survive and continue releasing virions for some time

Answer 49

TRUE

Question 50

# Ch 5 Actin filaments in the cytoskeleton can aid in the release of eukaryotic viruses

Answer 50

TRUE

Question 51

# Ch 5 Temperate phages must release from the host cell via lysis

Answer 51

FALSE

Question 52

# Ch 5 Temperate phages can integrate their genome with the host genome

Answer 52

TRUE

Question 53

# Ch 5 Host cells that are infected with a temperate virus cannot be infected by other virions of the same type

Answer 53

TRUE

Question 54

# Ch 5 temperate phages can alternate between lysogenic and lytic stages

Answer 54

TRUE

Question 55

# Ch 5 Lysogeny enables survival of host cells in an environment with low multiplicity of infection (MOI)

Answer 55

FALSE

Question 56

# Ch 5 A chronic infection is a situation in which a virus slowly releases virions without killing the cell

Answer 56

TRUE

Question 57

# Ch 5 Most human viruses associated with cancer have dsDNA genomes

Answer 57

TRUE

Question 58

# Ch 5 Some strains of human papillomavirus (HPV) can cause cervical caner

Answer 58

TRUE

Question 59

# Ch 5 Tumor activator proteins promote formation of tumors in human dsDNA viruses

Answer 59

FALSE

Question 60

# Ch 5 Viruses are easily cultivate in agars and broths, much like bacteria

Answer 60

FALSE

Question 61

# Ch 5 Plaque assays determine viral numbers based on infectivity of the virus

Answer 61

TRUE

Question 62

# Ch 5 The number of plaque-forming units (PFUs) is equal to the number of viruses because all virions are infective

Answer 62

FALSE

Question 63

# Ch 5 The infectious dose (ID60) of a virus is the dose that, when given to a number of hosts, causes and infection of 50% of the hosts under particular conditions

Answer 63

TRUE

Question 64

# Ch 5 Viroids, or infectious RNAs, cause many important plant diseases

Answer 64

TRUE