Yes, you can die from a low oxygen level, this is called anoxia.
fish will die
The air pressure would be very high, and we might die because of it. There might be low in oxygen because the atmosphere is very thin.
not unless you smoke it out in a room with low oxygen (death by suffocation) or unless your stuff is laced
No energy, hard to think, fever, terrible, terrible headache. Source: My experience, I went into the hospital with a hemoglobin level of 4.5. Doctors couldn't believe I was still conscious and walking around.
Deoxygenated blood is low in oxygen and high in carbon dioxide.
Depends how low. I have low oxygenation, and I am doing --- argh. Just kidding about the "argh". If the oxygen level gets low, you go to sleep (before you die). OH, by the way, I dumped my treatment when I found out the "system" was incrediably stupid. It wouldn't give me drugs to go out of state, and I was going. I didn't die out of state, and I now ignore the treatment. OK, I'm lucky. Figure out if you are lucky before you dump your drugs. I hope you are correct.
An area of the ocean with very low oxygen levels is called a "dead zone." Dead zones are often caused by excessive nutrient runoff from land, which leads to algal blooms. When these algae die and decompose, they consume oxygen in the water, creating hypoxic conditions that can be harmful to marine life.
The pulmonary veins are high in oxygen and low in carbon dioxide. All other veins are high in carbon dioxide and low in oxygen.
hypoxemia
The natural phenomenon is gravity. It allows the heavier oxygen to stay low.
To keep oxygen in the water for the bacteria that "eat" wastes in the water to help purify it. If the oxygen level gets to low, the bacteria die, and the water in the basin doesn't get cleaned.
Oxygen's ionization energy is relatively low compared to some other elements. It takes 1314 kJ/mol to remove an electron from a neutral oxygen atom to form an oxygen cation.