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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Aerobic and anaerobic respiration each have advantages under specific conditions. Aerobic respiration produces far more ATP, but risks exposure to oxygen toxicity. Anaerobic respiration is less energy-efficient, but allows survival in habitats which lack oxygen.
Within the human body, both aerobic and anaerobic respiration are important.
Answer:
Humans—and other complex multicellular organisms—have systems of organs that work together, carrying out processes that keep us alive. ... Cells make up tissues, tissues make up organs, and organs make up organ systems. The function of an organ system depends on the integrated activity of its organs.
