Chapter 6 : Viruses and other acellular infectious agents

Question 1

The study of viruses is called

Answer 1

Virology

Question 2

These agents are infectious and unique but simple and are acellular.

Answer 2

Viruses

Question 3

Which type of viruses only become active when in a living cell and cannot reproduce outside the living host?

Answer 3

Extracellular virus

Question 4

Which type of viruses command the host cell and hijack transcription/translation to synthesize viral components?

Answer 4

intracellular viruses

Question 5

Viruses that infect bacteria are called?

Answer 5

bacteriophages

Question 6

Most viruses effect eukaryotic cell like plants, animals, protists and fungi T o F?

Answer 6

True

Question 7

What is the nucleocapsid?

Answer 7

Composed of nucleic acid and protein capsid

Question 8

what does it mean by a enveloped virus?

Answer 8

the virus nucleocapsid is enveloped by lipid membrane

Question 9

How are the capsids synthesized in viruses?

Answer 9

by the host

Question 10

function of capsids in viruses?

Answer 10

to protect genetic material and aid in the transfer material

Question 11

What are the large macromolecules structures that serve as protein coat to viruses?

Answer 11

capsids

Question 12

What the different types of capsids?

Answer 12

Helical, polyhedral , spherical, and complex

Question 13

what are the protein subunits that makeup capsids?

Answer 13

protomers

Question 14

Capsids that are shaped like hallow tubes are called?

Answer 14

helical capsids

Question 15

Some viruses do not fit into the category of having helical or polyhedral capsids, these are called ?

Answer 15

Complex capsids

Question 16

What do the large bacteriophages capsids look like?

Answer 16

binal symmetry but icosahedral head but tail is helical

Question 17

Viral-enveloped viruses contain these structures that extend out for viral attachment are called?

Answer 17

Spike protiens

Question 18

Viruses can only have single-stranded DNA T o F?

Answer 18

False they can have single and double-stranded DNA or RNA

Question 19

What are the five steps to viral multiplication

Answer 19

attachment
entry to host
synthesis
assembly
virion release

Question 20

what is the main idea of tropism in regard to viruses?

Answer 20

Viruses will bind to only specific tissue receptors

Question 21

How do viruses attach to host cell ?

Answer 21

ligand on virus attached to a receptor on host

Question 22

What are the three methods used from a virus to enter host cell?

Answer 22

endocytosis
release NA
fusion of viral envelope with host Plasma membrane

Question 23

What can occur when virus attaches to host cell?

Answer 23

genome or entire capsid may enter the cytoplasm
genome may enter after leaving a capsid attached outside the cell
genome is enclosed

Question 24

What is the process of entry for viruses via fusion with plasma membrane?

Answer 24

1. Spike proteins bind to receptors
2. lipid bilayer fuses with envelope of virus
3. nucleocapsid is released

Question 25

What is the process for enveloped virus entering via endocytosis?

Answer 25

1. spike proteins bind to the host cell 2. triggers endocytosis 3. increase in acidity 4. nucleocapsid leave to cytoplasm

Question 26

What is the process for a virus entering via endocytosis that in nonenveloped?

Answer 26

1. capsid proteins attach to receptors of the host 2. trigger endocytosis 3. NA is taken out from endosome into cytosol

Question 27

For Ds DNA what is the typical synthesis ?

Answer 27

transcription and translation by host

Question 28

For RNA viruses synthesis typically occurs by?

Answer 28

carrying in or synthesizing the protein to complete synthesis

Question 29

Early proteins are involved in assembly and late proteins are involved with catalyzing expression and duplication T o F?

Answer 29

early - catalyze and duplication late - assembly

Question 30

what are the two virion release mechanisms?

Answer 30

host cell lysis ( non-enveloped) or release by budding ( enveloped)

Question 31

How many reproductive choices do virulent phages have?

Answer 31

one- multiply and released lytically

Question 32

How many reproductive choices do temperate phages have ?

Answer 32

two produce lytically or remain in host cell with no destruction

Question 33

what is it called when there is a relationship between a phage and a host?

Answer 33

lysogeny

Question 34

Form of the virus that remains within the host is called?

Answer 34

prophage

Question 35

Lysogenic bacteria are ?

Answer 35

infected bacteria

Question 36

what are cytopathic effects in regards to eukaryotic cells?

Answer 36

degenerative changes or abnormalities in host cell

Question 37

in plaque essay how are we able to know the presence of virus ?

Answer 37

the virus is diluted and they create plaques and the number correlate to number of viruses