1. The correct answer is no. Atenuation is not the product of an allosteric effect.
Atenuation is a regulatory mechanism of some bacteria which results in premature termination of transcription ( prevents completion of transcription). Atenuation is usually based on mRNA folding into alternative secondary structures.
2. The correct answer is: It does not involve conformational changes in protein structure.
Allosteric effect is the result of allosteric regulation which includes binding of an effector molecule to the allosteric site or regulatory site. Those sites allow effectors to bind to the protein and often result in a conformational change.
3. Attenuation is the result of both transcriptional and translational activities.
This is because in bacteria (where attenuation occurs), transcription and translation proceed simultaneously (are coupled). The mechanism of attenuation involves a stop signal called attenuator, which is located in the DNA segment. That DNA segment corresponds to the leader sequence of mRNA, so during attenuation, the ribosome becomes delayed in the attenuator region (mRNA).
