Which of the following is not a regulatory mechanism used to control the tryptophan operon in Escherichia coli?
A. Attenuation
B. Repression
C. Catabolite repression
D. All of the choices are correct.
Answer: C
You might also like to view...
Unequal crossing over often results in the formation of duplicate copies of existing genes. At what phase of meiosis can unequal crossing over occur, and why does this happen?
What will be an ideal response?
What is the likely consequence of a mutation that alters the branch point within an intron?
A. failure of snRNAs to combine with protein and form snRNPs B. no exon shuffling C. no effect, since introns are not expressed D. failure to form a lariat E. failure of snRNPs to recognize the 5' end of intron
Simple goiter can be prevented by
A. administration of insulin. B. administration of ACTH. C. surgery to remove the thyroid gland. D. increasing intake of iodine in the diet. E. removal of the pituitary.
Azolla filiculoides is a small aquatic fern that is typically 1-2 cm tall. How would a botanist distinguish it from a bryophyte?
A. It has xylem tissue. B. It produces seeds. C. It has chloroplasts. D. It has a gametophyte.