Jenney Exam 1

Question 1

Describe the lytic cycle.

Answer 1

Phage attaches to host cell
Phage DNA circularizes and enters cycle
Phage DNA and proteins synth and assembled into new phages in cell
Cell explodes and releases new phages

Question 2

Describe the lysogenic cycle.

Answer 2

Phage attaches to host
Phage DNA circularizes and enters cycle
Phage DNA integrate with chromosome
Prophage is formed 
Cell reproduces normally and copies prophage DNA

Question 3

What occurs when the phage DNA combines with the host chromosome?

Answer 3

Recombination

Question 4

What does the lysogenic cycle enter when it wants to excise from the chromosome?

Answer 4

Lytic cycle

Question 5

What are transpsons?

Answer 5

Sequences of DNA encoding an ezyme bound on either end of inverted repeats
Carries other genes when cleaved from starting location

Question 6

If a transposon is inserted into a gene what might occur?

Answer 6

Insertion within genes results in protein function loss or gene regulation loss

Question 7

What cleaves transposons from DNA to insert in random new locations?

Answer 7

Transposase

Question 8

What are pathogenicity islands?

Answer 8

Multiple genes surrounded by transposon-like elements that encode virulence properties
Encode for one of more virulence factors

Question 9

What is an insertion sequence?

Answer 9

Small base-pair sequences capable of self-insertion at multiple sites in the chromosome through transposase
Cleaved and moved

Question 10

Can an insertion sequence carry other genes with them?

Answer 10

No