The correct answer is protobiont.
Protobiont refers to the accumulation of the organic molecules, enveloped by a membrane, which abiotically unites into the resemblances of living matter, and are considered to be the precursors of prokaryotic cells.
The scientists consider that protobionts are the evolutionary precursors of the prokaryotic cells. They would have generated as an arrangement of microspheres of different inorganic and organic compounds surrounded by lipidic membranes. According to the scientists, RNA was the nucleic acid of the primitive protobionts.
Nitrogen,<span>The atmosphere is composed of ~78% nitrogen and ~21% oxygen, with small amounts of other gases. The bulk composition of the earth by weight is mostly, iron, oxygen, silicon and magnesium, in that order, with all the other elements making up only about 5% of the earth's weight.</span>
Tides and Water currents.
Elements [or radicals] with valency one are monovalent, those with valency two are divalent, and those with valency three are trivalent.
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What is the Valency of an Element / Radical?
Valency Divalent [2]
Element / Radical Oxide [Oxygen]
Symbol O
Ion O2-
