Biology Forums - Study Force

In bacterial mismatch repair the repair enzyme complex recognizes the parental strand since
A.  the parental strand has histones attached.
B.  the daughter strand is always in fragments.
C.  the parental strand contains more thymines.
D.  the parental DNA is methylated.
E.  the repair complex cannot tell the difference.


Which one of the following is defined as a sequence of bases in DNA which contains the information for one functional polypeptide?
A.  a codon
B.  a cistron
C.  a polysome
D.  a polycistronic message
E.  an operon


Adenylate cyclase is the enzyme which converts ATP to 5'-cAMP. What is the expected effect on the in vivo expression of the lactose operon of a nonsense mutation in the adenylate cyclase structural gene (which totally inactivates the enzyme)?
A.  No effect under any environmental conditions.
B.  The operon is transcribed at a high rate when cells are grown in a mixture of glucose plus lactose.
C.  The operon is transcribed at a high rate when cells are grown in a mixture of glucose plus lactose.
D.  The operon is transcribed at a high rate in the presence of lactose but a low rate in the presence of glucose and lactose.
E.  The operon is not efficiently transcribed in the presence of lactose.