Seeing that our species is constantly evolving, maybe it is starting to get more uncomfortable to walk on all fours.
Answer: Water can hold an unlimited amount of oxygen.
Explanation:
Water cannot hold an unlimited amount of oxygen because it would get to a point where it is saturated as it needs to hold Hydrogen as well. Air on the other hand, has significantly more space for oxygen as it contains only 21% and can keep taking more.
Underwater organisms need oxygen for respiration and a small decrease in the oxygen available in water affects aquatic life because they rely on it to survive.
Eukaryotes have a nucleus (like animal cells) but prokaryotes do not have a nucleus (they are plant cells)
I think it would be (from smallest to biggest) this info is from various sources and scientific PDFs
1Glucose=1nanometer
2Protein=10nanometer
3Disaccharides= 200+nanometer
4Starch=1000+nanometer
