The trp operon encodes the genes required to synthesize tryptophan. This operon is regulated by a feedback loop in which tryptophan binds to a transcriptional regulator leading to a change in gene expression from the operon. This is most likely an example of. a. inducible gene expression b. repressible gene expression c. constitutive gene expression d. post-translational regulation of gene expression

The correct answer is option b. "repressible gene expression".

Explanation:

The trp operon is a classic example of a repressible gene expression. The trp operon controls the biosynthesis of tryptophan from an initial precursor by encoding five genes that translate to three enzymes. These enzymes act as regulators and tryptophan itself acts as the final regulator. Tryptophan inhibits its own production when it binds to the transcription regulator, therefore it is an example of a repressible gene expression.