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
21.
The passage most strongly supports █████ ███ ██ ███ ██████████
a
Some peptides that ████ ██ ███████ ████████ ████ ████ ██ ██████ ██████████
Unsupported. We know that Belcher and Hu are working on peptides that bind to two different semiconductor crystals at once. But we don’t know whether those are one gallium arsenide crystal and one indium phosphide crystal. Maybe they’re two gallium arsenide crystals.
b
Researchers besides Belcher ███ ██ ███ █████ ██████████ ████ ███████ ███ ███████████ ██ █████ ████████ ██ ███ ████████ ██ █████████████
Unsupported. We know that some researchers are looking at using DNA to assembly nanocircuits. But the only peptide researchers we know about are Belcher and Hu.
c
Neither Belcher nor ██ ███ ████ █████ ██████████ ████████ ██ ███████ █████████ █████ ████ █████████
Unsupported. The author’s only interested in their peptide research. He simply doesn’t address whether they’ve done any non-peptide research.
d
Silicon, gallium arsenide, ███ ██████ █████████ ███ ███ ███ ████ █████████████ █████████ ██ █████ ████████ ████ ████ █████ ██ █████
e
Peptides have been ████ ██ ██████████ ████████████ ████ ███ ███ ███████ ██ ███████████████
Unsupported. The author’s only interested in the use of peptides for semiconductors. He simply doesn’t address whether they’ve been used in other applications.