This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!
This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!
This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!
"Surprising" Phenomenon
Why are small rats more likely than normal rats to suffer from heart problems, and large rats are less likely than normal to suffer form heart problems?
Objective
This is an EXCEPT question. The four wrong answers will help differentiate small rats from other rats in a way that makes them more likely to have heart problems, or it will help differentiate large rats from other rats in a way that makes them less likely to have heart problems.
A
Small rats are more likely than large rats to suffer from fatal diseases that tend to strike earlier than do heart problems.
This deepens our confusion. If small rats are more likely than large rats to die before getting heart problems, then we’d expect the overall rate of heart problems among small rats to be lower than for the other rats, who are more likely to survive to the age of getting heart problems.
B
Small rats generally have smaller blood vessels than do large rats, vessels that can more easily be clogged with fatty deposits.
If small rats have smaller blood vessels, which can be more easily clogged with fat, that’s a potential causal mechanism that could explain the smaller rats’ increased risk of heart problems.
C
The larger a rat is, the more successful it will be at defending itself, and therefore the less stressful its existence will be.
The smaller ones have more stress, which might lead to increased heart problems. The larger rats have less stress, which might lead to fewer heart problems. And the average rats are in the middle for stress, which might lead to being in the middle for heart problems.
D
In addition to being the leading cause of weak hearts in adult rats, malnutrition at early stages of development causes rats to be undersized.
This tells us malnutrition causes both a weak heart and smaller body size. This could explain why the smaller rats have more heart problems: those rats were more likely to be the malnourished ones.
E
Although large rats are no more active than rats of average size, they tend to be much more active than small rats, resulting in greater cardiovascular conditioning.
(E) establishes that small rats have less cardiovascular conditioning (meaning conditioning related to the heart) than the average and large rats. This helps explain why small rats have more heart problems than the other groups.
This page shows a recording of a live class. We're working hard to create our standard, concise explanation videos for the questions in this PrepTest. Thank you for your patience!