PrepTest 123, Section 3, Question 11
By Brandon Beaver | Published October 29, 2024
Type: Necessary Assumption
Difficulty:
Explanations
Well, hold on. This bird was stuffed and preserved? Does that perfectly preserve mercury levels? Also, the passage says that the mercury accumulates “as the feathers grow.” Were these 1880s seabirds younger than the modern birds they were compared to? Furthermore, the mercury “is derived from fish eaten by the bird.” Is it possible that 1880s seabirds didn’t like fish as much or that those 1880s fish had less mercury in them?
A
No, the opposite! The passage assumes that the proportion was as high or higher, on average, in the 1880s as today.
B
Pollution isn’t mentioned. Didn’t read? Don’t pick!
C
The usefulness of mercury is not the topic.
D
No, the passage almost assumes the opposite (it technically isn’t an assumption, because the modern birds could have also been not fully grown).
E
Now we’re talking. It’s possible that the birds did have the same amount of mercury. However, when they were “stuffed and preserved,” they lost a substantial amount of mercury because of the preservation process.
Passage
Feathers recently taken from seabirds stuffed and preserved in the 1880s have been found to contain only half as much mercury as feathers recently taken from living birds of the same species. Since mercury that accumulates in a seabird's feathers as the feathers grow is derived from fish eaten by the bird, these results indicate that mercury levels in saltwater fish are higher now than they were 100 years ago.
Question 11
The argument depends on assuming that
the proportion of a seabird's diet consisting of fish was not as high, on average, in the 1880s as it is today
the amount of mercury in a saltwater fish depends on the amount of pollution in the ocean habitat of the fish
mercury derived from fish is essential for the normal growth of a seabird's feathers
the stuffed seabirds whose feathers were tested for mercury were not fully grown
the process used to preserve birds in the 1880s did not substantially decrease the amount of mercury in the birds' feathers