Answer:
After several million years, the Earth separated into several layers. Iron, nickel and other heavy metals mostly settled to the core; lighter elements remained in the mantle around the core. The lightest elements, such as oxygen and silicon, floated to the top and cooled, forming a solid crust. Because the Earth was not completely liquid, the layering process was uneven; pockets of heavy elements remained in the crust.
Interphase consists of G1,S and G2.
Cells grow and more importantly replicate(duplicate) their DNA(S phase) during interphase.
Oxygen was initially created in Earth's atmosphere by algaes. It is estimated that marine plants produce between 70 and 80 percent of the oxygen in the atmosphere. Nearly all marine plants are single celled, photosynthetic algae. Hope this answers the question.
<span>Chemical reactions that ____________________ energy will not occur without a source of energy.
RELEASE
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Mutation ( that’s what I put )