<span>Carbon dioxide is a colorless and odorless gas that is vital to life on Earth. This naturally occurring chemical compound is made up of a carbon atom covalently double bonded to two oxygen atoms. Carbon dioxide exists in Earth's atmosphere as a trace gas at a concentration of about 0.04 percent by volume. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, in ice caps and glaciers and also in seawater. It is present in deposits of petroleum and natural gas.</span>
Answer:
Prokaryotes are smaller and less developed compared to eukaryotes. Some of them inhabit very primitive environments that resemble earth’s early stages. Endosymbiotic theory states that eukaryotes arose by the endosymbiosis of prokaryotes.
Explanation
By endosymbiont theory, eukaryotic cells arise from prokaryotic cells. Here, the theory shows that eukaryotic ancestors lived in close association with prokaryotes, wherein in some cases, prokaryotes have been engulfed and might have lived inside eukaryotes.
Upon being engulfed by a host cell as undigested prey, these prokaryotes could have been internal parasites of the eukaryotes. But, later on, their relationship becomes mutualistic and these prokaryotes become incorporated as organelles, such as in the case of chloroplasts and mitochondria, which were previously separate prokaryotes
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