Genetic Exchange

Question 1

Transformation

Answer 1

DNA binding
Penetration
Integration

Question 2

DNA binding - ds DNA is nicked and cleaved by

Answer 2

Membrane bound endonuclease

Question 3

During uptake one strand is hydrolyzed by

Answer 3

Envelope associated exonuclease

Question 4

Penetration through

Answer 4

Membrane spanning DNA translocase channel

Question 5

Transformed DNA is integrated if

Answer 5

Nucleotide sequence homology b/w donating and recipient chromosome

Question 6

Gram positive

Answer 6

Neisseria gonorrhoeae

Question 7

Protein -a
Pilin complex -b
DNA binding protein - c
Nuclease -d
Membrane channel protein -e

Answer 7

A- pilinQ.
B- pilE. ComGC
C- comE comEA
d- N. N
e- comA. comEC

Question 8

Hfr conjugation

Answer 8

The f plasmid is integrated in bacterial chromosome
The tra operon is still functional and can form sex pilus , carry out rolling circle replication , and transfer the f plasmid
However the f plasmid instead of transferring itself it directs the transfer of whole chromosome ( f+ bacterial chromosome)
Ecoli 100 min
Recipient cell remains f- but since the bacterial chromosome is also transferred there is high frequency of recombination

Question 9

Conjugation

Answer 9

Tra operon
Sex pilus formation
Type IV secretion apparatus
Rolling circle replication
Transfer of plasmid

Question 10

F’

Answer 10

F plasmid is an episome this it can restore it’s autonomous form from its integrated state .
Error in excision = f plasmid plus a part of bacterial chromosome = f ‘
The f’ strain bacterial cell retains all its bacterial genes except few of them are now in in f’ plasmid
Bacterial genes from its chromosome are not transferred but the ones in f ‘ plasmid a re transferred this the recipient cell becomes partially diploid merozygote