Answer:
Transcribing the lacl sequence
Explanation:
lacZ, lacY, and lacA sequences are the structural genes, which needs to be expressed in order to produce their proteinous enzymes required for the breaking down of lactose sugar. The transcription of these three genes must occur with the aid of RNA polymerase binding to them.
However, a gene sequence called lacI encodes information for an repressor, which when expressed can inhibit the expression of the genes lacZ, lacY, and lacA. Hence, the TRANSCRIPTION OF THE LACL SEQUENCE cause the cell to not express the lacZ, lacY, and lacA sequences.
