1.
he structural genes in an operon are all co-transcribed as a single mRNA when the operator is
bound by the regulator. are transcribed individually as separate mRNAs when an operator is
bound by the regulator. are transcribed individually when the regulator molecule is bound at the
operator for each gene. are all cotranscribed as a single mRNA when the operator is not bound
by the regulator. O are transcribed individually as separate mRNAs when an operator is not
bound by the regulator.
Solution
The structural genes in an operon are all cotranscribed as a single mRNA when the operator is
not bound by the regulator because when the operator binds tightly to the operator preventing
transcription by RNA polymerase. However, when operator not bind DNA then It floats off the
operator, clearing the way for RNA polymerase to cotranscribe the operon as a single mRNA .So
Option 4 is correct.