chapter 5 and 11

Question 1

What type of parasites are viruses?

Answer 1

viruses are obligate intracellular parasites.

Question 2

What is a key structural feature that all viruses contain?

Answer 2

Viruses contain a protein coat.

Question 3

What do viruses lack that is essential for energy production?

Answer 3

Viruses lack an ATP-generating mechanism.

Question 4

What determines the host range of a virus?

Answer 4

Host range is determined by specific host attachment sites and cellular factors.

Question 5

What molecules do viruses contain instead of ribosomes?

Answer 5

Viruses contain DNA or RNA, but not ribosomes.

Question 6

What are viral spikes used for?

Answer 6

spikes are used for attachment to host cells.

Question 7

Do all viruses have an envelope?

Answer 7

No, only some viruses are enclosed by an envelope.

Question 8

What structure do all viruses have

Answer 8

All viruses have a nucleocapsid.

Question 9

What type of genetic material do viruses contain?

Answer 9

Viruses contain either DNA or RNA, but not both at the same time.

Question 10

What is the shape of most viral nucleic acids?

Answer 10

Most viral nucleic acids are linear, although some are circular.

Question 11

What makes up the protein coat of a virus?

Answer 11

The protein coat, called the capsid, is made of building blocks known as capsomeres.

Question 12

What is the envelope of some viruses made of?

Answer 12

The envelope is made of a lipid bilayer.

Question 13

What are spikes in viruses?

Answer 13

Spikes are embedded proteins on the virus surface.

Question 14

What is the function of lysozyme in viruses?

Answer 14

Lysozyme helps bacteriophages make holes in the cell wall and lyse the bacterial cell upon exit.

Question 15

What is the role of nucleic acid polymerases in viruses?

Answer 15

Nucleic acid polymerases are enzymes that assist in replicating the virus’s genetic material.

Question 16

What is the function of neuraminidases in viruses?

Answer 16

Neuraminidases cleave glycosidic bonds and help release viruses from host cells.

Question 17

how big is capsid of virus of t-even bacteriaphage

Answer 17

65 nm

Question 18

What are the two main types of symmetrical virion morphology?

Answer 18

Icosahedral-Polyhedral and Filamentous-Helical.

Question 19

What is the shape of a symmetrical icosahedral virus?

Answer 19

It is polyhedral, having 20 faces.

Question 20

What is a filamentous-helical virion?

Answer 20

A virus with a long, thread-like structure that is coiled into a helical shape.

Question 21

What is the morphology of an asymmetrical virion?

Answer 21

An asymmetrical virus has a complex structure.

Question 22

What are the criteria used by the ICTV to classify viruses?

Answer 22

Genome composition, capsid symmetry, envelope, size of the virion, and host range.

Question 23

What types of hosts are considered in virus classification by the ICTV?

Answer 23

Bacteria, Archaea, Animals, and Plants.

Question 24

Which virus characteristic is used to classify viruses based on the shape of the protein coat?

Answer 24

Capsid symmetry.

Question 25

What classification factor involves whether a virus has a lipid bilayer surrounding it?

Answer 25

Envelope.

Question 26

What are the primary distinctions used in the Baltimore Classification of viruses?

Answer 26

Genome composition (RNA or DNA) and the viral replication strategy.

Question 27

What does the Baltimore Classification system focus on regarding viral mRNA?

Answer 27

The route used to express messenger RNA (mRNA).

Question 28

Who proposed the Baltimore Classification system?

Answer 28

David Baltimore in 1971.

Question 29

What type of genome does Group I of the Baltimore Classification contain?

Answer 29

Double-stranded DNA.

Question 30

What type of genome does Group II of the Baltimore Classification contain?

Answer 30

single-stranded DNA.

Question 31

What type of genome does Group III of the Baltimore Classification contain

Answer 31

Double-stranded RNA.

Question 32

What type of genome does Group IV of the Baltimore Classification contain?

Answer 32

(+) Single-stranded RNA.

Question 33

What type of genome does Group V of the Baltimore Classification contain?

Answer 33

(–) Single-stranded RNA.

Question 34

What type of genome does Group VI of the Baltimore Classification contain?

Answer 34

RNA retroviruses.

Question 35

What type of genome does Group VII of the Baltimore Classification contain?

Answer 35

DNA pararetroviruses.

Question 36

What do family names of viruses end in?

Answer 36

viridae.

Question 37

What do genus names of viruses end in?

Answer 37

virus.

Question 38

What defines a viral species?

Answer 38

A group of viruses sharing the same genetic information and ecological niche (host).

Question 39

How are viral subspecies designated?

Answer 39

By a number.

Question 40

What family does the Herpesvirus belong to?

Answer 40

Herpesviridae

Question 41

What is the genus of the Herpesvirus?

Answer 41

Herpesvirus

Question 42

What is the term used to refer to human herpesviruses?

Answer 42

Human Herpesvirus (HHV)

Question 43

What are the types of Human Herpesvirus (HHV)?

Answer 43

HHV-1, HHV-2, HHV-3

Question 44

What family does the Lentivirus belong to?

Answer 44

Retroviridae

Question 45

What is the genus of the virus causing HIV?

Answer 45

Lentivirus

Question 46

What viruses are part of the Human Immunodeficiency Virus (HIV)?

Answer 46

HIV-1, HIV-2

Question 47

How must viruses be grown?

Answer 47

Viruses must be grown in living cells.

Question 48

What is the result of growing bacteriophages in a lawn of bacteria?

Answer 48

Bacteriophages form plaques on a lawn of bacteria.

Question 49

What are some methods used to grow animal viruses?

Answer 49

Living animals Embryonated eggs Cell culture Continuous cell lines

Question 50

What method involves growing viruses in fertilized eggs?

Answer 50

Embryonated eggs

Question 51

What type of cell culture is often used for growing viruses?

Answer 51

continuous cell lines

Question 52

What are the methods used for virus identification?

Answer 52

Cytopathic effects Serological tests Nucleic acids

Question 53

What do serological tests detect in a patient?

Answer 53

Serological tests detect antibodies against viruses in a patient.

Question 54

What is one way to identify viruses using antibodies?

Answer 54

Use antibodies to identify viruses in a patient.

Question 55

What are examples of serological tests for virus identification?

Answer 55

Neutralization tests Viral hemagglutination Western blot

Question 56

What does RFLP stand for and how is it used in virus identification?

Answer 56

RFLP stands for Restriction Fragment Length Polymorphisms. It is used to analyze viral DNA for identification.

Question 57

What does PCR stand for, and how is it used in virus identification?

Answer 57

PCR stands for Polymerase Chain Reaction. It is used to amplify viral DNA or RNA for identification

Question 58

What are the two main cycles of bacteriophage multiplication?

Answer 58

lytic cycle Lysogenic cycle

Question 59

What happens in the lytic cycle of a bacteriophage?

Answer 59

The phage causes lysis and death of the host cell.

Question 60

What happens in the lysogenic cycle of a bacteriophage?

Answer 60

The prophage DNA is incorporated into the host's DNA.

Question 61

What is phage conversion?

Answer 61

phage conversion occurs when a bacteriophage changes the characteristics of the host cell, often by integrating new genes.

Question 62

What is specialized transduction?

Answer 62

Specialized transduction is the process where a bacteriophage transfers specific genes from one bacterium to another by integrating into the host genome.

Question 63

The Lytic Cycle: Virulent Mode

Answer 63

Attachment Entry/Penetration Biosynthesis Assembly/Maturation Release

Question 64

Attachment:

Answer 64

phage attaches by tail fibers to

Question 65

Entry/Penetration:

Answer 65

phage lysozyme opens cell wall; tail sheath contracts to force tail core and DNA into cell

Question 66

Biosynthesis:

Answer 66

production of phage DNA and proteins

Question 67

Assembly/Maturation:

Answer 67

assembly of phage particles

Question 68

Release:

Answer 68

phage lysozyme breaks cell wall

Question 69

What does burst size refer to in virus replication?

Answer 69

Burst size refers to the number of virions (new viral particles) released from a host cell after it has completed the replication cycle.

Question 70

What is a permissive cell in the context of viral replication?

Answer 70

A host cell that supports the full replication cycle of a virus.

Question 71

What are the three parts of the T4 genome?

Answer 71

Early and middle proteins Late proteins Phage DNA

Question 72

What do early and middle proteins in T4 do?

Answer 72

They include enzymes for DNA replication and transcription.

Question 73

What do late proteins in T4 do?

Answer 73

They form head/tail proteins and enzymes to release mature phage.

Question 74

What is produced during infection by T4?

Answer 74

T4 nucleases, DNA polymerase, and new sigma factors.

Question 75

What proteins are part of the T4 phage structure?

Answer 75

Phage head, tail, collar, base plate, and tail fiber proteins.

Question 76

What does T4 lysozyme do?

Answer 76

It helps release mature phage particles by breaking down the host cell wall.

Question 77

What types of mRNA are involved in T4 infection?

Answer 77

Early mRNA Middle mRNA Late mRNA

Question 78

What occurs during T4 infection timeline?

Answer 78

Early proteins: Transcription/translation Middle proteins: DNA replication Late proteins: Self-assembly and lysis