The answer is D, photosynthesis and respiration.
—Evidence—
Oxygen is a byproduct of photosynthesis and, correspondingly, carbon dioxide the byproduct of respiration.
Oxygen gives our cells the ability to break down food in order to get the energy we need to survive. Although other animals may use different organs to breathe with, they all get oxygen into their bodies through respiration.
Answer:
Im waiting on an answer aswell.
Explanation:
<span>The burners must be turned off because, in the case of liquid chromatography, the eluant solvents being used are flammable. Leaving the burners lit could cause the eluant to catch on fire, putting the scientist at risk.</span>
The secondary succession is triggered by a natural event (forest fires for example) that destroys an established ecosystem. The destroyed forest will then undergo a regrowth process. This secondary growth may look bizarrely different from the way how the original forest used to look like. There are several stages involved after the forest os being burned. The first stage involves the colonization of massively burned places by plants and fungi. The following stage starts when minuscule plants such as grasses dwell in the forest. And then, huge plants that require lots of direct sunlight will move in. Lastly, new trees will continuously grow up to a point where they makeup a forest that remains in time except there are major interventions.
The way that you will easily deduce which one it is is that you'll see the mouth first instead of the anus because of the different ways of development.