A flu shot consists of a vaccine against several strains of influenza virus. This year, you get the shot and "the flu." What happened? (There are at least three explanations.)

Going for a check up and taking the appropriate medication.

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."