What led to the increase in oxygen levels in the atmosphere on primitive Earth?
a. the first photosynthetic reactions
b. photosynthetic cells that used water and not H2S as a source of electrons
c. the development of cellular respiration pathways in cells
d. the use of glycolysis in cells
e. photosynthetic pathways that stripped oxygen off of carbon dioxide and retained only the carbon in subsequent
steps
ANSWER: b
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Basic dyes
A. have negative charges. B. have positive charges. C. are electrically neutral. D. contain both positively and negatively charged particles.
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What will be an ideal response?