Why is earthquake prediction a challenge for scientists

Reliable predictions require precursors – some kind of signal in the earth that indicates a big quake is on the way. The signal has to happen only before large earthquakes and it has to occur before all big quakes.

Explanation:

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."