Self-study
P1
Every culture that has adopted the cultivation of maize—also known as corn—has been radically changed by it. ███
intro topic ·
Influence of maize
explain significance ·
of maize
Contributed to development of agrarian and urban societies, and European population growth
hypothesis ·
Maize's influence is due to its productivity
phenomenon ·
Productivity of maize
Intro to hypothesis ·
Biochemistry provides the answer
P2
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Context ·
Explanation of photosynthesis
Water splits into hydrogen and oxygen, hydrogen produces energy. Meanwhile, carbon dioxide builds sugars with help from enzyme (rubisco).
Problem ·
Too much oxygen interferes with photosynthesis
Enzyme supposed to work with carbon dioxide, but oxygen binds to enzyme instead, meaning less enzyme available to work with carbon dioxide
P3
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Solution (hypothesis) ·
Different method of photosynthesis
Enzyme (rubisco) is kept separate from atmospheric gases (e.g., oxygen and carbon dioxide)
Complication with hypothesis ·
Carbon dioxide cannot reach enzyme as gas
Solution: Carbon dioxide becomes nongas molecule (C-4) in order to reach enzyme and drive photosynthesis
Strengthen hypothesis ·
Other highly productive crops use this method of photosynthesis
Passage Style
Phenomenon-hypothesis (RC)
Single position
22.
Which one of the following ████ ██████████ █████████ ███ ████████████ ██ ███ ████████ █████████ ██ ███ ██████ ███ █████ ██████████ ██ ███ ████████
a
The author suggests ████ ███ ██████████ ███████████ ██ █ ██████████ ████ ██ ███ ██ ███ ████ ██████ ████████ ███ ████ █████ ██ ██████████ ███ ██████ ██ █ ██████████ ██████ ██ ████ █████ ███ ████ ████████ ███ ███████ ███ ███ █████████ ██ ████ ███████
Inaccurate. This describes P1 (maize’s widespread cultivation is due to its high yield) and, to some extent, P3 (its high yield is a result of how the enzyme rubisco is kept away from oxygen). It then describes information not contained in the passage at all (the author doesn’t discuss any reasons for the evolution of rubisco).
b
The author explains ████ ███████ ██ █ ███████████ ████████ █████████ █ █████████ █████████ █████████ ██ ████ ████████ ███ ████ █████████ ██ ████████████ ████████ ██ ████ █████████ ██ █████ ██ ███████ ███ ████████████ ██ █ ██████████ █████
This is a good low-res summary of P2 and P3. P2 explains the biochemical process of photosynthesis and describes a hindrance to photosynthesis (oxygen interferes with rubisco). P3 then describes a solution that C-4 crops have evolved to solve that problem (they separate oxygen from rubisco). This solution is what explains the productivity of maize.
c
The author describes █ ███████ ████████ ██ ███████ ███████████ ██████████ ██████████████ ████████ ███ ████ ██ █████ █████████ █████ ████ ████████ ███ ████ ████████ ███ ████████████ █████ ███ ███ ██ █████ ██████████
Inaccurate. The author does describe a problem inherent in photosynthesis (oxygen interferes with rubisco), but only explains one way in which organisms solve it (the C-4 process). She also doesn’t explain any evolutionary “basis” for the C-4 process.
d
The author describes █ ██████████ ████████ ██████████ █████████ ███████ ████ ██ █ ████ ██ ██████ ████████ ███ ███████████ █████ ██ ███ ███████████ ███ ████ ██████ ███ ████ ███████ █████ ██████ ███ ██ ████ ███ ███████ █████████
Inaccurate. Cultural considerations are only discussed in P1.
e
The author introduces █ ███████ ████████ █████████ ███ ███████████ ████████ ████ ██ ██████ ████ ██ ██ ███ █████████ ██████████ ███ ████████ ███ ████ ██████ ███ ██ █████████ ████████████ ███████████ ██ ████ ████████
Inaccurate. The author does introduce a natural process (photosynthesis) and describes the underlying mechanism in P2. But she doesn’t argue for any “alternate evolutionary explanation” of photosynthesis. Rather, she ends P2 by explaining a particular problem with photosynthesis, and then spends P3 explaining how C-4 plants overcome that problem.