試題詳解

2. Which of the following statements is   correct   about a pair of lac operons with the following merodiploid genotype in E. coli strain? : a mutation in the operator that makes it defective in binding repressor)
(A) The mutation is cis-dominant.
(B) Both operons are uninducible.
(C) This merodiploid is a complete diploid bacterium.
(D) lac products cannot be produced in the absence of lactose.
(E) The repressor binds irreversibly to both operators.