Chapter 19

Question 1

Virus

Answer 1

is and infectious particle consisting of genes packaged in a protein coat

Question 2

capsid

Answer 2

the protein shell that encloses the viral genome

Question 3

Capsids are built from protein subunits called

Answer 3

capsomeres

Question 4

A capsid can have a variety of structures; associated viruses may be referred to as

Answer 4

helical or icosahedral viruses

Question 5

Viral envelopes

Answer 5

surround capsids of influenza and others found in animals

Question 6

Bacteriophages (Phages)

Answer 6

Viruses of bacteria

Question 7

Lytic Cycle

Answer 7

-Phage cycle with host cell death
-Produces new phages and lyses (Breaks open) Hosts cell wall, releasing progeny viruses
-Virulent Phage: Phage only using lytic cycle

Question 8

Lysogenic cycle

Answer 8

Phage genome replicates without destroying host

Question 9

Phages that use both the lytic and lysogenic cycles are called

Answer 9

Temperate Phages

Question 10

Retroviruses use

Answer 10

reverse transcriptase to copy their RNA genome into DNA

Question 11

Provirus

Answer 11

Viral DNA integrated into host genome

Question 12

Vaccines

Answer 12

Harmless derivatives of pathogenic microbes that stimulate immune system to mount defenses against harmful pathogens

Question 13

Viroids

Answer 13

Small circular RNA molecules that infect plants and disrupt their growth

Question 14

Prions

Answer 14

Slow-acting, virtually indestructible infectious proteins that cause brain diseases in mammals