Multiple Choice
The lac repressor has been mutated so that its binding site for the operator has been altered to the extent that it is unable to bind to the operator.What is the likely effect of this mutation on the lac operon?
A) The repressor will be unable to bind to the operator; the operon will bind RNA polymerase and it will thus be turned on.
B) The repressor will bind to the operator despite the mutation, and will suppress transcription of the operon in the presence and absence of lactose.
C) The lac operon will be protected by the altered repressor.
D) The repressor will be unable to bind to the operator; therefore, the ability of RNA polymerase to bind there will be severely hampered.
Correct Answer:

Verified
Correct Answer:
Verified
Q68: The sequence of nucleotides in an mRNA
Q69: A tRNA molecule produced in a laboratory
Q70: A codon can specify up to three
Q71: If a strand of DNA has the
Q72: The base sequence of mRNA specifies the
Q74: The stop codon is the sequence of
Q75: The position of the start codon is
Q76: A gene affects an organism's phenotype by
Q77: Proteins are produced directly from DNA,with no
Q78: The sugar molecule present in RNA is<br>A)