A normal heart rate ranges between 60-100 beats per minute. The higher the heart rate is, the faster the blood is pumping through the heart. When exercising a persons heart will be higher because the brain and the muscles in the body are in need of oxygen so the heart needs to pump faster in order to sustain optimal performance.<span />
According to a source the answer is <span><u>Cyanobacteria were the first organisms to produce oxygen in water, which then escaped into the atmosphere.</u>
These cyanobacteria species were the first ones to "produce" oxygen as a by-product of the photosynthetic mechanisms which enables organisms to make their own food. </span>
I think either neutral ph or more enzyme
Sperm will have 23 chromosomes while the egg has 23 chromosomes
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