Ans. 'false.'
Lac operon or lactose operon in bacteria represents a set of genes, responsible for the transport and metabolism of lactose by bacterial cells.
The 'i⁺' represents a wild-type regulatory gene, which expresses regulatory protein and transcription is regulated, while 'i⁻' represents a mutant regulatory gene that cannot make regulatory protein.
The 'o⁺' represents a wild-type operator sequence that can be repressed by a functional regulatory protein, while 'oc' represents a defective operator, by which the repressor protein cannot bind and thus, transcription is always on (constitutive expression).
The z⁺ represents wild-type structural gene that gets expressed, when transcription is on, while z- represents mutant and defective structural gene, thus, no lactose metabolism will occur.
Hence, in given bacterial cell, the repressor protein cannot not bind to both operator as operator of 'i+ocz⁻' haplotype represents a constitutive operator, by which repressor protein cannot bind and operon is always on.
Thus, the given statement is 'false.'
