Which of the following statements about regulation of the lac operon is true?
A. When glucose is present, gene expression is activated by lactose.
B. The amount of glucose in the growth medium does not affect the level of gene expression activated by lactose.
C. The binding of the Lac repressor to the operator is not affected by the presence of glucose.
D. Gene expression is high when the Lac repressor is not bound to the operator and glucose is available.
C
You might also like to view...
Organs are made up of ________ type(s) of tissue.
A. Two or more B. Two C. One D. At least five
What is the primary function of the transverse tubules?
A. They conduct action potentials from the surface of the muscle fiber to internal regions near myofibrils. B. They act as a channel for Ca2+ ions during excitation-contraction coupling. C. They form cross-bridges between actin and myosin during muscle contraction. D. They attach troponin to tropomyosin. E. They attach muscle fibers to skeletal elements to exert force.
Which of the following represents the correct order of vertebrate gastrointestinal tract layers, going from outside the tract to inside the tract?
A. the serosa, submucosa, and the lumen B. the submucosa, the mucosa, the lumen, the plexuses, and the serosa C. the serosa, the mucosa, and the submucosa D. the serosa, submucosa, and the mucosa E. the mucosa, the plexuses, and the serosa
The letter "C" in the figure above represents
a. root apical meristem. b. dermal tissue. c. vascular tissue. d. ground tissues. e. ground, dermal, and vascular tissues