1. Biological Processes
2. Geological Processes
3. Chemical and Physical Processes
<span>4. Human Activity ( hope this helps )</span>
It may be determination (not sure though)
That would be the chloroplasts. They are small cells in a leaf that store chlorophyll.
Convection occurs over a very very long time in the earth's mantle. Rock slowly gets melted down from the core, then shoots back up from volcanoes. The new rocks get buried by sand and sediments, and the process resets.
