basic concept part 2

Question 1

steps in viral replication

Answer 1

1. Attachment
2. Penetration
3. Uncoating
4. replication
5. assembly
6. release

Question 2

involves the interaction of viral
attachment proteins (VAPs) and specific host
-cell
receptor sites

Answer 2

attachment

Question 3

can occur by a cellular mechanism
called receptor
-mediated endocytosis, which is
referred to as viropexis when viruses are involved

Answer 3

penetration

Question 4

refers to the separation of the capsid from
the viral genome. It results in the loss of virion
infectivity

Answer 4

uncoating

Question 5

process by which enveloped
viruses obtain their envelope and confers
infectivity to enveloped viruses

Answer 5

budding

Question 6

(lysis of naked viruses or budding of
enveloped viruses

Answer 6

release of virus

Question 7

It is preceded by
the insertion of virus
-specific glycoproteins into the
membranes of the host cell. It occurs most
frequently at the plasma membrane, but also
occurs at other membranes

Answer 7

budding

Question 8

the
inside of the membrane becomes coated with
a virion structural protein called

Answer 8

matrix or M protein

Question 9

occurs in the host-cell nucleus (except
for poxviruses) and is regulated by host cell DNAdependent RNA polymerases (`

Answer 9

transcription

Question 10

occurs on cytoplasmic polysomes and is
followed by transport of newly synthesized proteins to
the nucleus

Answer 10

Translation

Question 11

occurs after the synthesis of the
early proteins.

Answer 11

. Genome replication

Question 12

a group of ribosomes bound
to an mRNA molecule like “beads” on a
“thread

Answer 12

polyribosome

Question 13

occurs on cytoplasmic polysomes.

It may result in the synthesis of a large
polyprotein that is subsequently cleaved into
individual viral polypeptides

Answer 13

translation

Question 14

Involves a viral-specified RNA dependent RNA polymerase for all viruses, except
retroviruses, which use a host-cell, DNA-dependent
RNA polymerase.

Answer 14

transcription

Question 15

It results when surface antigens
from two related viruses enclose the genome of one
of the viruses.

Answer 15

phenotypic typing

Question 16

occurs when
pairs or related viruses infect the same cell.

Answer 16

2. Phenotypic masking

Question 17

occur when two mutants of
the same virus or, less frequently, two mutants of
different large DNA viruses, infect the same cell

Answer 17

Complementation

Question 18

occur when two strains of
a segmented RNA virus infect a cell.

Answer 18

. Genetic reassortment

Question 19

can be constructed with recombinant
DNA technology and allow gene transfer into cells

Answer 19

viral vectors

Question 20

. Phenotypic masking also known as

Answer 20

transcapsidation

Question 21

ability of a given virus to productively
infect a particular cell

Answer 21

viral tropism

Question 22

the virus and host cell enter into a
peaceful coexistence, both replicating independently
without any cellular injury, a condition known as

Answer 22

‘steady
state infection.’

Question 23

presence of appropriate receptors on
the surface of the cell determines whether virus can
adsorb to it and the virus gets into the cell

Answer 23

Cellular factors

Question 24

viruses kill the cells in which they
replicate, sometimes with characteristic appearances or
cytopathic effect

Answer 24

Cytopathic effect

Question 25

types of inclusion bodies

Answer 25

Intracytoplasmic inclusion bodies
Intranuclear inclusion bodies

Question 26

Viruses have
evolved mechanisms to continue to survive in the face
of a strong host immune response

Answer 26

Latent and persistent infections