Phage Genetics

Question 1

2 types of viruses:

Answer 1

1. Virulent

2. Temperate

Question 2

genetic elements that can replicate independently of a cell’s chromosomes but not independently of cells themselves

Answer 2

Virus

Question 3

2 states of viruses

Answer 3

Extracellular state & Intracellular state

Question 4

state of virion

Answer 4

Extracellular state ; cannot replciate

Question 5

complete complex of nucleic acid and protein packaged in the virus particle

Answer 5

nucleocapsid

Question 6

2 types of nucleocapsid

Answer 6

enveloped, naked

Question 7

2 types of shapes

Answer 7

rod, spherical

Question 8

2 types of symmetry

Answer 8

helical, icosahedral

Question 9

e.g. of helical symmetry

Answer 9

Tobacco mosaic virus

Question 10

e.g. of icosahedral

Answer 10

Human wart virus

Question 11

Enzymes in virions (4)

Answer 11

a. Nucleic Acid Polymerase
b. Reversetranscriptase
c. Neuraminadases
d. Lysozyme

Question 12

transcribe viral nucleic acid to mRNA

Answer 12

Nucleic Acid Polymerase

Question 13

transcribes the information in the incoming RNA into DNA intermediate

Answer 13

Reversetranscriptase

Question 14

used in liberation of mature phages during the Lytic phase

Answer 14

Neuraminadases

Question 15

action of lysozyme

Answer 15

makes a small hole in bacterial cell wall that allows viral nucleic acid to enter

Question 16

Steps in Virus Multiplication

Answer 16

1. Attachment
2. Penetration
3. Early replication
4. Replication
5. Synthesis of proteins
6. Assembly of structural subunits
7. Release of mature virion

Question 17

2 Protein categories

Answer 17

1. Early proteins – for replication

2. Late proteins – for the protein coat of the virus