Self-study
Conclusion One theory to explain the sudden extinction of all dinosaurs points to "drug overdoses" as the cause. ████████████ █ ███████ █████ ██ ███████ █████ ████████ ██ ███ ████ ████ █████████ ██████ ████████ █████ ██████ ███████ ████████████████ █████████ ████ ███ ████████████ ███████ ████ ████████████ ███████ █████ █████ ███████████ ██████ ███████ ███████ ████ █████ ███████ █████████ ███████ ████ ██████ ████ ████ ████████ ████ ██████ ████████ █████████ █████ ███████ █████ ███ ██████████ ███ ████████ ███ █████████ ████ ██ ███ █████████ ████ ██████ ████████ ███ █████████ ███████ ████ ███ ████ ████ ██ █████ ███████ ███ ██ ████ ████████ ███████ ███ █████ ██ ███████ ███ █████████ ██████████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that “overdoses” on plants called angiosperms could’ve caused the sudden extinction of all dinosaurs. She bases this on the fact that dinosaurs couldn’t taste the plant’s bitterness or detoxify its poison, and that many dinosaur fossils are found in unusual and contorted positions.
Notable Assumptions
The author assumes that the fossils’ contorted positions are caused by poisoning from angiosperms, without considering other possible explanations for their positions.
The author assumes that, just because dinosaurs couldn’t avoid angiosperms by tasting their bitterness, they couldn’t avoid them at all. She thus assumes that dinosaurs were eating any angiosperms, a point which is never established.
She also assumes that angiosperms, which were “potentially lethal,” were deadly enough to cause the immediate extinction of all dinosaurs.
19.
Which one of the following, ██ █████ █████ ████ █████████ ███ ██████ █████████ ██████
a
Many fossils of █████ ███████ ███ █████ ██ █████████ ██████████
(A) undermines the theory by showing that there must be some other cause for the contorted shapes of large animals’ fossils. Most mammals avoided angiosperms but many still have contorted fossils. So, something other than angiosperms must have caused those fossil positions.
Plausibility
Plausibility
Presenting evidence that corroborates (in Strengthen) or conflicts (in Weaken) with the author's hypothesized explanation or the predictions that follow from that explanation.
b
Angiosperms provide a █████ ████ ██ ██████████
This doesn’t weaken the argument because, even if angiosperms did provide nutrition, they were also poisonous. We also still don’t know that dinosaurs ate angiosperms in the first place.
c
Carnivorous dinosaurs mostly ███ ██████ ███████████ █████████ ████ ███ ██ ████████████
By showing that some dinosaurs ate angiosperms, (C) slightly strengthens the argument. It doesn't challenge the author's theory or her assumptions that angiosperms were toxic enough to cause dinosaurs' extinction or that the contorted fossil positions were due to these plants.
d
Some poisonous plants ██ ███ ███████ ████████████████ ██████████
This doesn’t change the fact that angiosperms do produce amino-acid-based alkaloids. So it does nothing to weaken the theory or to show that the author’s many assumptions are invalid.
e
Mammals sometimes die ██ ████ █████████ ████ ██████ ████████████
We still don’t know that dinosaurs ever ate angiosperms, but (E) shows that angiosperm overdoses can cause death. So, if anything, this slightly strengthens the theory by confirming that angiosperms are poisonous enough to occasionally kill mammals.