Describe one observation that supports the theory that mitochondria and chloroplasts originated as independent prokaryotic organisms

How does a gymnosperm prevent itself from pollinating the same tree

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?

Which ocean is on the eastern coast of north and south america? arctic ocean indian ocean pacific ocean atlantic ocean