Which of the following accounts for the negative control of operons?
a. promoters
b. repressors
c. structural genes
d. operators
e. deactivators
ANSWER: b
You might also like to view...
When killifish were present, what was the main selection factor affecting the average number of spots on male guppies?
a. reduction in spot number to avoid predation b. increase in spot number to attract females c. both selective forces were in effect when killifish were present
Vascular tissue that transports organic nutrients and sugars from the leaves to the roots is
A. phloem. B. cambium. C. xylem. D. periderm. E. sclerenchyma.
Which of the following statements is/are true of long noncoding RNAs?
A) They are involved in X chromosome inactivation. B) They can silence genes by promoting the formation of euchromatin. C) They can regulate the translation and stability of mRNAs. D) They can trigger the activity of histone acetyltransferases.
Which of the following statements about collagen isfalse?
(a) Collagen synthase organizes the mature collagen molecules into ordered collagen fibrils. (b) Collagen is synthesized as procollagen and secreted to the outside of the cell in a secretory vesicle. (c) The terminal procollagen domains are cleaved by a protease in the extracellular space. (d) Cells can break down a collagen matrix using matrix proteases.