Answer:
2, 1, 4, 3
Explanation:
2
Denaturation by Heat to separate double-stranded DNA into two single strands
1
Annealing Primer to Target Sequence
The primers that anneal (bind) to the complementary sequence marks the DNA target sequence
4
Extension
New double stranded DNA molecules that is identical to the original double stranded target DNA region is formed
3
End of the First PGR Cycle
Fresh DNA polymerase is added