I believe it’s A. -ist. I hope this helps I’m sorry if it doesn’t :)
Since the particles of gas all try to separate and move into equilibrium when exposed to space, all of the particles have been moved out to a certain ratio of particle per air, if that makes sense. When moved to a bigger space, the concentration of the particles aren't as condensed. So therefore, the particles will move out and put more space in between each particle. They will all be spaced out, and there will be less total particles of gas per square inch of air.
Explanation:
Methemoglobin (metHb) is an oxidized derivative of hemoglobin in which heme iron is in the ferric (Fe3+) or oxidized state rather than the ferrous (Fe2+) or reduced state. Small amounts of methemoglobin normally are formed daily, associated with the release of oxygen from hemoglobin (auto-oxidation).
Methemoglobin cannot bind oxygen, which means it cannot carry oxygen to tissues. It is bluish chocolate-brown in color. In human blood a trace amount of methemoglobin is normally produced spontaneously, but when present in excess the blood becomes abnormally dark bluish brown. The NADH-dependent enzyme methemoglobin reductase (a type of diaphorase) is responsible for converting methemoglobin back to hemoglobin.
Normally one to two percent of a person's hemoglobin is methemoglobin; a higher percentage than this can be genetic or caused by exposure to various chemicals and depending on the level can cause health problems known as methemoglobinemia. A higher level of methemoglobin will tend to cause a pulse oximeter to read closer to 85% regardless of the true level of oxygen saturation. An abnormal increase of methemoglobin will increase the oxygen binding affinity of normal hemoglobin, resulting in a decreased unloading of oxygen to the tissues.
Here's the excerpt.
Guppies are small, tropical freshwater fish that display wide variation in coloration. Some have bright splotches of blue, red, and orange, while others are quite drab and dull. Research has shown that females prefer to mate with brightly colored males; however, this trait makes them more likely to be seen. Guppies, like all species, must be able to both sur<span>vive and reproduce in order to avoid extinction
One process that is responsible for the variations in coloration observed in guppies is that how females mate with male guppies. They prefer to mate with brightly colored males.</span>
