Which of the following occurs as a result of an abundance of tryptophan in E. coli?
A.The leader sequence is not transcribed.
B.The 5 trp genes (TrpA ? TrpE) are not transcribed.
C.Stalling of the ribosome at trp codons in the leader sequence
D. The 5 trp genes (TrpA ? TrpE) are transcribed, but not translated.

Which of the following features of the trp operon is likely least essential to the process of attenuation?
A.The order of the structural genes, E, D, C, B, A
B. Trp codons near the beginning of the leader sequence
C. The ability of sequences within the leader mRNA to pair with one another
D. Transcription and translation of the leader sequence occur simultaneously.