Lactic acid is a byproduct of short-term cellular respiration do to exercise, but if you mean lactose, then it's just the enzymes, that your stomach produces
<span>The atomic mass is the number of protons plus the number of neutrons in an atom.</span>
An abiotic factor is a non living thing
4. nucleoid region
Bacterial cell's do not have a nucleus; their DNA is found in this region.