Question

What discovery suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme?

a. Kornberg DNA polymerase mutants died.
b. Kornberg DNA polymerase mutants grew much more slowly.
c. Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a normal rate. d. Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a low rate.
e. Kornberg DNA polymerase mutants reproduced much faster than normal bacteria.

Answer 1

The discovery that mutants with less than 1% normal Kornberg DNA polymerase enzyme activity could still multiply normally, suggested the presence of alternative DNA polymerases in bacteria.

Step-by-step explanation:

The discovery that suggested the presence of other DNA polymerases in bacteria besides the Kornberg DNA polymerase enzyme was c. Mutants with <1% of the normal Kornberg DNA polymerase enzyme activity multiplied at a normal rate. This observation indicates that despite the low level of the traditional Kornberg enzyme, also known as DNA pol I, bacteria were still capable of replicating their DNA, implying the existence of additional polymerases facilitating the process.

These alternate DNA polymerases, such as DNA pol II and DNA pol III in prokaryotes, play key roles in DNA replication and repair activities. DNA pol III is primarily responsible for DNA synthesis, whereas DNA pol I functions in DNA repair and removing RNA primers during replication. The ability of DNA replication to continue with markedly reduced levels of DNA pol I suggested the redundancy and specialization of the enzymatic machinery in bacterial cells.