Molecular clocks because the m<span>easure changes in DNA or proteins to indicate degrees of relationship among species.Molecular clocks, together with evidence from the fossil record, allows scientists to estimate how long ago various groups of organisms diverged evolutionarily from one another</span>
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
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<span>Photosynthesis</span>- the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
Just as a dozen is 12 of something, a mole is about 6.02 * 10^23 of something .