निम्नलिखित में से कौन सा एंजाइम 90°C के ऊपर के तापमान पर स्थिर और सक्रिय रहता है?

Which of the following statements are correct with respect to DNA separation, isolation and visualization? A. The cutting of DNA is done by molecular scissors. B. The DNA fragments separate according to their size in an agarose gel, upon electrophoresis. C. The separated DNA fragments can be seen without staining when exposed to UV light. D. The separated DNA fragments, when stained with ethidium bromide, can be seen in visible light. Choose the correct answer from the options given below:

Identify the correct sequence of steps in each cycle of Polymerase Chain Reaction (PCR):