Which is biotic?
soil
leaf
water
snow

Explanation:

A biotic components from the given options of soil, leaf, water, snow is leaf

A leaf is a part of a plant and all plants are living thing. They possess all the characteristics of living things

Biotic components of an ecosystem are all the living organisms present in the system.

Learn more about biotic components:

link

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."