Exam 4: Ch 22

Question 1

productive infections

Answer 1

Outcome of a viral infection in which new infectious viral particles are produced

Question 2

abortive infections

Answer 2

Outcome of a viral infection in which few if any new infectious viral particles are produced

Question 3

acute infections with example

Answer 3

Infection of short duration. most common type
Ex: a typical rhinovirus infection

Question 4

episome

Answer 4

Circular piece of viral DNA separate from the host chromosome(s) within the nucleus of a host cell

Question 5

latency-associated transcript (LAT)

Answer 5

Herpesvirus transcript made during latency

Question 6

persistent infection

Answer 6

Viral infection during which new viral particles are continuously produced; also called a “chronic infection”

Question 7

endogenous retrovirus

Answer 7

Viral infection during which new viral particles are continuously produced; also called a “chronic infection”

Question 8

inclusion body

Answer 8

Microscopically visible granule within the cell; composed of aggregated cellular or viral materials

Question 9

autoimmunity

Answer 9

Immune reactions directed inappropriately against the body’s own cells

Question 10

molecular mimicry

Answer 10

Process in which immune cells react against host antigens that resemble antigens of a pathogen

Question 11

transformation

Answer 11

A type of horizontal gene transfer in which a piece of free DNA is taken up by a cell; change within a cell that causes it to become cancer-like

Question 12

tumorignenesis

Answer 12

Formation of a tumor

Question 13

oncogene

Answer 13

Altered form of a proto-oncogene that can lead to uncontrolled cell growth and the development of tumors

Question 14

quiescent cell

Answer 14

Cell that is not actively dividing

Question 15

tumor suppressor

Answer 15

Cellular protein that inhibits cellular replication

Question 16

immunoprecipitation (IP)

Answer 16

Technique in which an antibody is used to precipitate an antigen

Question 17

cis-acting retrovirus

Answer 17

Retrovirus that activates a cellular proto-oncogene after integrating into a host chromosome

Question 18

proto-oncogene

Answer 18

Gene involved in normal cell growth

Question 19

transducing retrovirus

Answer 19

Retrovirus that has acquired a cellular gene and can transfer it to a new cell

Question 20

antigenic drift

Answer 20

Gradual change in viral antigens caused by random mutation

Question 21

reassortment

Answer 21

Packaging of gene segments from two or more parental virus strains into one virus

Question 22

antigenic shift

Answer 22

Dramatic change in viral antigens caused by reassortment

Question 23

latent infection with example

Answer 23

These viruses typically undergo a period of acute replication immediately after infecting a host. Subsequently, the production of new viral particles stops. Some event then may cause the production of new viral particles to resume, a process referred to as reactivation.
Ex: herpesvirus

Question 24

Be familiar with processes that contribute to virus evolution

Answer 24

mutations, recombinations, reassortment

Question 25

Persistent infection and example

Answer 25

For most classic persistent infections in humans, the production of viral particles continues for years after the initial infection
Ex: mammalian reoviruses

Question 26

RNA viruses pick up mutations frequently. Why

Answer 26

they lack a proofreading ability therefore making more alterations in genetic code when transcripting and replicating

Question 27

Apoptosis and its importance during viral infections

Answer 27

it “safely” kills virally infected cells to save cells around it