How can a new element be made, a by changing the number of neutrons in the atom, b by changing the number of protons in the atom, c by changing the number of electrons in the atom, d new elements cannot be made from existing elements

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."

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.