Self-study
This passage was adapted from an article published in 2000.
P1
Problem ·
Computer chips will hit a point where they can't be made any smaller
With current methods, transistors (devices that make up computer chips) cannot be made smaller than 25 nanometers.
Potential solution ·
Natural chemical processes might produce smaller molecules that act like transistors
Belcher and Hu ·
B and H are investigating peptides
Others are researching DNA to try to create small transistor-like molecules. B and H are researching something else -- peptides.
P2
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Background leading to research ·
Arose from research that found peptides could cause calcium carbonate to form structure found in abalone shell
B and H thought peptides might create crystalline structures associated with transistors.
B and H's research ·
Grew a billion different peptides, found that some can bind to semiconductor materials
P3
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Future research ·
Identifying additional organic compounds that can bind to additional semiconductor mateirals
Passage Style
Problem-analysis
Single position
16.
Which one of the following ████ ██████████ █████████ ███ ████ █████ ██ ███ ████████
a
Although preliminary results ███████ ████ ███████ ███ ████ ████████ ██ ████████ ███ ██████████████ █████ ██████ ██ █ ████████████ ██ ███ ███████████████ ██ ████████ ██████ ██████ █████████ ██████ ██ ████ ████ ██ ███████ █████████
“Unlikely” is wrong. Obstacles remain, but the author doesn’t suggest that the odds of success are low.
b
Advances in computer ████ █████ ███ ██████████ ██████ ███ ████ ████ ███ ██████ ██ ███ ███████ ██ ███████ ███████ ████████ █████████ █████████ ████ █████████ ██ ███████ ███ ███ █████ █████ ██ █████ ████████ ██ ████ █████████ ████████ █████████
This description of Belcher and Hu’s research is too narrow. Their research focus isn’t limited to using peptides to bind different crystals together; that’s just a part of their
c
Belcher and Hu's ████████ ██ ███ █████████ ██ ████ ████████ ██ ████ ██ █████████████ █████████ █████████ ████ ████████ █████ ██████████ ██ ███████ ██ ███ ██████████ ██ ████████ █████ ████ ███████████ ███████ ████ ███ █████ █████ ███ ██ ███████ ████████
This is a good summary of the problem (how to create transistors smaller than the current lower limit) and the progress toward a solution (Belcher and Hu’s research).
d
Belcher and Hu's █████████ ██ ████████ ████ █████ ███ ███████████ ██ █ ██████████ ███████████ █████████ ██ █ ███████ ██████████ ███████ ████████ ████ █████████████ █████████ █████ ████ ██ ██████████ ██████████
Descriptively inaccurate. Their discovery didn’t suggest that semiconductors might bind to biological compounds. It suggested that peptides might help create certain semiconductors and might bind one semiconductor crystal to another. Also, (D) is incomplete as the main point. Belcher and Hu went on to demonstrate that this use of peptides is in fact possible.
e
The application of █████████ ████ ██ ███████ ██ ███ █████ ██ ██████████████ █████ ████ ████ ██████████ ████████ ███ ████ ██████████ █████████ ██████████████
Was Belcher’s work “pure scientific research” and were the results “unexpected”? The author doesn’t say. Perhaps Belcher was always looking for way to build smaller transistors, in which case her research was applied (not “pure”) and the results weren’t unexpected.