I wanna say the answer is B
in the nucleolus of the cell
The primary function of the respiratory system is to supply blood with oxygen
An increase in genetic variation
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.
