Prokaryotes were the first organisms to evolve on Earth, so, the first prokaryotic cells appeared 3.8 billion years ago. After them, Eukaryotic unicellular organisms developed, when one cell engulfed the other cell (endosymbiotic theory). Those unicellular eukaryotes form multicellular aggregates and that represents an evolutionary transition from single cells to multicellular organisms. Multicellular organisms evolved from unicellular eukaryotes at least 1.7 billion years ago.
<span>About
2 billion years passed between the appearance of the first prokaryotic cells and the emergence of multicellular organisms.</span>
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Cellular respiration<span> is a set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. ... </span>Respiration<span> is one of the key ways a</span>cell<span> releases chemical energy to fuel </span>cellular<span> activity.</span>
The full statement is this: In 1859, Charles Darwin wrote, 'The ........................... ...... At the based of the evolutionary tree of all life is AN ORGANISM THAT IS A COMMON ANCESTOR TO ALL LIVING ORGANISMS.
In biology, evolution has to do with gradual but constant changes in the overall form of living organism. Scientists believe that all life forms came from a common ancestor; it is through the process of evolution and natural selection that primitive life forms developed into higher forms of living organisms. In short, what the statement given in the question is trying to say is that ALL LIVING ORGANISMS ARE RELATED BECAUSE THEY HAVE A COMMON ROOT (A COMMON ANCESTOR).