What is the primary characteristic on which the first division of organisms is made ?

How does a gymnosperm prevent itself from pollinating the same tree

Mineral rich water heated by newly found oceanic crust escapes through cracks in the ocean floor called

What causes eclipses? check all that apply. earth's rotation on its axis moon's shadow covering the sun earth's shadow covering the moon earth's orbit and moon's orbit occasionally aligning the moon and sun's gravity pulling in the same direction