24. since the relative concentration of water in the
pond in which a paramecium (a single-celled
organism) lives is greater than the concentra-
tion of water in its cytoplasm, water molecules
constantly move from the pond into the
paramecium. the best long-term solution to
the problem of maintaining a stable internal
environment is for the paramecium to
(1) change the water into carbon dioxide and
excrete it
(2) store water molecules
(3) incorporate water molecules into its
structure
(4) actively transport water molecules out of
its cell
which is the answer?

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.  

d. organisms have cells with different shapes and functions.