The mechanism of phase variation in Salmonella typhimurium:

A. uses site-specific recombination to invert the fljA and fljB genes so they now are not contiguous with their promoter. Expression of these genes is now prevented.
B. uses site-specific recombination to invert the fljA and fljB promoter, preventing transcription of the two genes. Without repressor the fljC protein is now expressed.
C. uses site-specific recombination to delete the repressor, fljA. Without repressor the fljC protein is now expressed.
D. uses site-specific recombination to delete the fljB gene so only fljC can be expressed.
E. None of the choices given is true.


B

Biology & Microbiology

You might also like to view...

Campylobacter infections are the MOST common foodborne infections in the United States

Indicate whether the statement is true or false.

Biology & Microbiology

What is the method called that indicates the

age of material by measuring the content of the radioisotope and the daughter elements?

a. radiometric dating b. carbon dating c. catastrophism d. all of these e. none of these

Biology & Microbiology

Ecology and environmentalism are the same scientific discipline

Indicate whether the statement is true or false

Biology & Microbiology

One function of the developing follicle is to:

a. stimulate ovulation. b. secrete progesterone. c. secrete estrogens. d. secrete prolactin. e. secrete glycoproteins, which promote sperm motility.

Biology & Microbiology