Self-study
P1
The survival of nerve cells, as well as their performance of some specialized functions, is regulated by chemicals known as neurotrophic factors, which are produced in the bodies of animals, including humans. ███
Context ·
Nerve cells are regulated by chemicals called neurotrophic factors
Spotlight ·
Levi-Montalcini's discovery of NGF was important development in biochemistry
NGF was the first known neurotrophic factor.
P2
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Levi-Montalcini's hypothesis ·
Many nerve cells are programmed to die
Experimentation ·
Discovered that nerve development could be stimulated in chick embryos by implanting tumors
Additional hypothesis ·
Chemical produced by tumors caused nerve growth
Experimentation ·
Tissue culture method confirmed hypothesis and identified the "nerve growth factor" (NGF)
P3
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Later research ·
NGF directs nerves toward appropriate connections, and is necessary for survival of nerve cells
Passage Style
Single position
Spotlight
15.
Which one of the following ████ ██████████ █████████ ███ ████ █████ ██ ███ ████████
a
Levi-Montalcini's discovery of ████████████ ███████ ██ █ ██████ ██ ████████ ███████ ███ ██ ███ █████ ███ █ █████ ████████████ ██ ███ █████████████ ██ ███ ████ ██ █████████ █████████ ██████████ ██████████ ████ ██ ███ ███████████ ██ █████ ████████
This is too focused on chick embryos. Although Levi-Montalcini did use chick embryos in her tests, the overall impact of the discovery of NGF relates to more than just chick embryos.
b
Levi-Montalcini's discovery of ████ █ ████████████ ██████ ████ ██████████ ███ ███████████ ██ ████ █████ ██ █████ ██████ ███ █████ ████████ ██ ███████ ██ ███████████ █████ █████ █████████ ███████ ██████████ █████ █████ ████ ████████ ███ █ ███████ ███████████ ██ █████████████
This best captures the main point, which is that Levi-Montalcini’s discovery of NGF was a “
c
NGF, which is █████████ ███ ███ ████████ ███ ██████ ███████████ ██ █████ ██████ ███ ██████████ ██ ███████████████ ██ █ ██████ ██ ███████████ █████ ███ █████████ ██ ██████ ████████ █████ ███ ███████ ██ ███ ██████
This doesn’t capture the impact of the discovery of NGF. The author’s main point isn’t just the details of the discovery of NGF; it encompasses the impact of the discovery on biochemistry, too.
d
Partly as a ██████ ██ █████████████████ █████████ ██ ███ ████ █████ ████ ███ ███ █████ ████████████ ███████ ███ ████████ ████ ██ ███████ ██ █████ ██████ ███ ███████ █████████ ███ ████ ███ ████████ ██ █████ ███████ ██ █████████ ███ ███ ██████ ███ ██████ ███████████ ██ ███████ ████████
Not supported, because NGF and similar chemicals are also produced by tissues to which nerves “
e
NGF, a chemical ████ ███ ██████████ ██ ████████████████ ███████ ███ ██████ ██ █████ █████ ██████ ███ █████ ████ █████ ████ ████ ███████ ███ ███████ ███ ████████ ██ █████ █████ █████ ██████████ ███ ████ ██ ███ ████████ ██████ ████ ███ ████████ ████████ ████████ ███████████
This is too narrow to be the main point. The author’s main point should encompass the impact of the discovery on biochemistry. The main point isn’t merely a description of NGF and what it does.