How is lac operon transcription regulated by the presence or absence of lactose?
a. When lactose is not available, the repressor will bind to the promoter and block RNA
polymerase from transcribing the genes of the lac operon.
b. When lactose is available, the repressor will bind to the lactose instead of blocking RNA
polymerase.
c. When lactose is not available, the repressor will bind to allolactose.
d. When lactose if available, allolactose is produced and binds to the operator, blocking RNA
polymerase.
e. In the absence of lactose, transcription occurs at a low level resulting in the production of
allolactose which in turn stimulates the cell to take up lactose.
B
You might also like to view...
One square meter of open ocean areas supports more phytoplankton growth than a comparable coastal water area
Indicate whether the statement is true or false
Which of the following attributes is not common to the life and transmission cycles of Opisthorchis sinensis, Clonorchis sinensis, and Fasciola hepatica?
A. Eggs are released in the feces. B. Infection causes obstruction of the bile duct. C. Fresh water snails are an intermediate host. D. They are transmitted by consuming inadequately cooked fish.
Which of the following is NOT one of the types of variation that occurs within individuals?
A) genetic variation B) environmental variation C) normalizing variation D) genotype-by-environment variation
A research scientist is trying to design a new antibiotic that would break down the gelatinous capsule that surrounds each bacterial cell
What action would this antibiotic prevent in bacteria that would make it effective in preventing human illness? A) passing genes to each other B) swimming away from cells of the immune system C) attaching to body cells in order to cause infection D) reproducing using binary fission