Which of the following are examples of the effects of living things on the atmosphere and climate?

outgassing of volcanoes
the buildup of oxygen in the atmosphere
mass extinctions
changes in levels of carbon dioxide

The build up of oxygen in the atmosphere and changes in the levels of carbon dioxide. Brainest please.

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."

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.