1. Viruses Part 2

Question 1

What is prophage?

Answer 1

upon infection, the phage genome is incorporated into the bacterial genome

Question 2

What is lysogen?

Answer 2

host after the phages genome is incorporated into its own genome

Question 3

Why does dormancy occur during the lysogenic cycle of phages?

Answer 3

phage-encoded repressor protein binds to specific DNA elements in phage promoters blocking transcription of phage genes

Question 4

What is excision?

Answer 4

process of removing the phages genome from the host genome to enter the lytic cycle

Question 5

What is transduction?

Answer 5

the process of the phage genome incorporating previously stolen bacterial genome back into the newly infected bacterium

Question 6

What is endocytosis?

Answer 6

infection of animal cells by a virus whereby the host engulfs the virus and internalizes it

Question 7

What does it mean for a virus to be uncoated?

Answer 7

released from its capsid

Question 8

What three cycles can animal viruses enter?

Answer 8

1. lytic cycle
2. productive cycle
3. lysogenic cycle

Question 9

What is the productive cycle?

Answer 9

similar to the lytic cycle but does not destroy the host cell

Question 10

What is a provirus?

Answer 10

dormant form of the viral genome in the lysogenic cycle

Question 11

What four features determines the uniqueness of each virus?

Answer 11

1. type of genome
2. posession or lack of an envelope
3. nature of the cell-surface proteins
4. type of life cycle