Assuming that the genes required for Isoleucine (an amino acid) biosynthesis are contained within an operon. If the cell is grown in the presence of high amounts of isoleucine you would expect to find:
The repressor protein to bind to the operator, allowing transcription.
The repressor protein released from the operator, allowing transcription.
The repressor protein to bind to the operator, preventing transcription.
The repressor protein released from the operator, preventing transcription.

Question

Assuming that the genes required for Isoleucine (an amino acid) biosynthesis are contained within an operon. If the cell is grown in the presence of high amounts of isoleucine you would expect to find:
 The repressor protein to bind to the operator, allowing transcription.
 The repressor protein released from the operator, allowing transcription.
 The repressor protein to bind to the operator, preventing transcription.
 The repressor protein released from the operator, preventing transcription.

luigi0210 · Answer

If a cell is grown in an environment abundant with Isoleucine while it synthesis the amino acid, it is going to stop building it. 

If the cell can absorb what it needs from it's surroundings, it is going to stop producing that material. Otherwise it is just going to waste energy. So it is going to bind and stop transcription.