A bacterium inherits a mutation that renders its topoisomerase enzyme nonfunctional.What phenotype would you expect to see in this bacterium?
A)The cell would accumulate broken DNA because overwinding cannot be corrected,so the cell will be unable to replicate and will die.
B)The cell would accumulate supercoiled DNA,but otherwise it is perfectly normal.
C)The cell would accumulate relaxed DNA,which would make DNA replication and cell division highly disorganized and lead to cell death.
D)The cell would accumulate relaxed DNA,but otherwise it is perfectly normal.
E)The cell would be unaffected because bacteria have many different topoisomerases that are involved in replication.

Question

Quizplus · Accepted Answer

Topoisomerases are enzymes that relieve tension and untangle DNA during replication, transcription, and other DNA processes. A mutation that renders the topoisomerase enzyme nonfunctional would inhibit the cell's ability to correct overwinding and accumulate broken DNA, preventing the cell from replicating and causing its death. The other options are unlikely because they do not account for the role of topoisomerases in DNA maintenance.

A Bacterium Inherits a Mutation That Renders Its Topoisomerase Enzyme