The polymerase chain reaction (PCR)technique could be developed only after the discovery of bacterial enzymes that were able to withstand high temperatures. Why was it necessary to use such enzymes?
A)Only bacterial DNA can be copied using the PCR method, so bacterial enzymes were necessary.
B)Bacterial enzymes can move through the gel only during PCR electrophoresis.
C)DNA can be cut into fragments only at high temperatures.
D)The temperature required to separate DNA strands during PCR degrades most normal enzymes.

Question

Quizplus · Accepted Answer

The temperature required to separate DNA strands during PCR is approximately 95°C, which degrades most normal enzymes. Bacterial enzymes, however, have evolved to withstand high temperatures in their natural environment (e.g., high-temperature hot springs), making them ideal for use in the PCR technique. Choice A is incorrect because the PCR method can be used to amplify DNA from any organism, not just bacteria. Choice B is not true because bacterial enzymes do not affect the movement of DNA fragments through electrophoresis gels. Choice C is incorrect because DNA can be cut into fragments using a variety of methods, not just high temperatures.

The Polymerase Chain Reaction (PCR)technique Could Be Developed Only After