Which of the following would be examples of abiotic factors in a mountain river ecosystem? fish, algae, and sand

sand, water, and fish

sand, water, and minerals

water, fish, and algae

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 are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: