Why would a meteorologist compare a new weather map with one that is 24 hours old?

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.

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."

there’s no image attached but i can if you want: )