CH 19

Question 1

Virus

Answer 1

-an 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

Viral envelopes

Answer 3

-surround the capsids of influenza viruses and many other viruses found in animals
-derived from membranes of host cells

Question 4

Bacteriophages/phages

Answer 4

-are viruses that infect bacteria
-have an elongated capsid head

Question 5

Host Range

Answer 5

-a limited number of host cells that it can infect

Question 6

Lytic Cycle

Answer 6

-a phage replicative cycle that culminates in the death of the host cell

Question 7

virulent phage

Answer 7

-A phage that reproduces only by the lytic cycle

Question 8

lysogenic cycle

Answer 8

-replicates the phage genome without destroying the host

Question 9

temperate phages

Answer 9

-Phages that use both the lytic and lysogenic cycles

Question 10

prophage

Answer 10

-integrated viral DNA

Question 11

restriction enzymes

Answer 11

-cellular enzymes that identify and cut up foreign DNA

Question 12

Retroviruses

Answer 12

-RNA animal viruses with the most complicated replicative cycles

Question 13

reverse transcriptase

Answer 13

-used to copy their RNA genome into DNA

Question 14

HIV (human immunodeficiency virus)

Answer 14

-is the retrovirus that causes AIDS (acquired immunodeficiency syndrome)

Question 15

provirus

Answer 15

-viral DNA that is integrated into the host genome

Question 16

vaccine

Answer 16

-harmless derivatives of pathogenic microbes that stimulate the immune system to mount defenses against the harmful pathogen

Question 17

epidemic

Answer 17

-general outbreak
-In 2009, a epidemic of a flu-like illness appeared in Mexico and the United States, caused by an influenza virus named H1N1

Question 18

pandemic

Answer 18

-global outbreak

Question 19

Prions

Answer 19

-infectious proteins that appear to cause degenerative brain diseases in animals