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
18.
Which one of the following ██████████ █████ ███ ████████ ████ ███████ ███ ██ ██████ ██ ████████ ██ ██████████████ ███ ██ ████ ██████████ ████████ ████ ███ ████████
a
At least some ██ ████ ███ ███ ██████████ █████ ██ ███████
Strongly supported. When Belcher and Hu started testing,
b
At least one ██ ████ ███ █████ ██ ████ ██ █████ █████████ █████████████ ██████████
Unsupported. The peptides we’re talking about were tested to see whether they could bind to silicon or gallium arsenide or indium phosphide. Some peptides were found that could bind
c
At least some ██ ████ ████ ██████ ██ ████████ ██ ███████ ███ ███ ██ ████████ ██ ███████ █████████
Unsupported. The peptides we’re talking about were tested to see whether they could bind to silicon, gallium arsenide, or indium phosphide. It’s not clear, though, whether every peptide was tested with all three compounds, or whether some were tested with one compound and not another.
d
At least one ██ ████ ███ ██ ███ ██ ███ ████████ ████ ████████ █████ ██ ███████ ███ ████ █████████
Unsupported. We know that when Belcher and Hu started testing,
e
Other researchers had ██████████ ██████ ██ █████ ████ ██ ████ ███ ████████ █████████ ████ █████████████ █████████ █████ ████ ████████ ███████ █████████ ███ ██████ ██████████
Unsupported. We know Belcher and Hu tested for reactions with these three semiconductor materials. If other researchers were investigating other materials, the passage is silent about it.