Which of the following occurs when substances undergo chemical changes?

bonds between atoms are broken and new bonds are formed.

atoms change from one element into another element.

old atoms are destroyed and new atoms are created.

atoms change in size and shape to form new substances.

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."

is in the form atp or adenosine triphosphate