GRE Reading Comprehension
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Source: OG2
When marine organisms called phytoplankton photosynthesize, they absorb carbon dioxide dissolved in seawater, potentially causing a reduction in the concentration of atmospheric carbon dioxide, a gas that contributes to global warming. However, phytoplankton flourish only in surface waters where iron levels are sufficiently high. Mar- 5 tin therefore hypothesized that adding iron to iron-poor regions of the ocean could help alleviate global warming. While experiments subsequently confirmed that such a procedure increases phytoplankton growth, field tests have shown that such growth does not significantly lower atmospheric carbon dioxide. When phytoplankton utilize carbon dioxide for photosynthesis, the carbon becomes a building block for organic 10 matter, but the carbon leaks back into the atmosphere when predators consume the phytoplankton and respire carbon dioxide.
Question List: 1 2
It can be inferred from the passage that Martin's hypothesis includes which of the following elements?
- A A correct understanding of how phytoplankton photosynthesis utilizes carbon dioxide
- B A correct prediction about how the addition of iron to iron-poor waters would affect phytoplankton growth
- C An incorrect prediction about how phytoplankton growth would affect the concentration of atmospheric carbon dioxide