Exams › NEET › Biology

Jacob and Monod described the lac operon in E. coli, which includes a promoter, an operator, and three structural genes labeled z, y, and a. These genes encode β-galactosidase, permease, and transacetylase, respectively. The i gene, which is the regulatory gene, produces a repressor protein. When the inducer is absent, the repressor attaches to the operator, blocking RNA polymerase from binding to the promoter and halting transcription of the structural genes.

1. Correct
2. Incorrect
3. Partially correct
4. Not applicable

Correct answer: Correct

Solution

The statement is correct. In the absence of the inducer (like lactose), the repressor protein coded by the i gene binds to the operator region, blocking RNA polymerase from transcribing the structural genes of the lac operon.

Related NEET Biology questions

• Which of the following is a transcription factor produced by a regulatory gene?
• Which of the following combination is false?
• Which scientist experimentally proved that DNA is the sole genetic material in bacteriophage?
• If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6 × 10⁹ bp, then the length of the DNA is approximately
• Which of the following RNAs should be most abundant in animal cell?
• The final proof for DNA as the genetic material came from the experiments of:

⚔️ Practice NEET Biology free + battle 1v1 →