PrepTest 102

Incorrect. This answer suggests a similarity between the two types of primroses, so it can't explain the discrepancy in rarity.

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
Self-pollinating vs. Non-self-pollinating primroses:
(1) The former have higher average seed production
(2) Otherwise, they're indistinguishable
(3) The former are rare

Answer Anticipation:
As with all Paradox questions, we should start by defining the paradox. And, as with many Paradox questions, this one deals in comparisons, so we should approach it through that lens.

Here, the paradox is that self-pollinating primroses have a higher average seed production. That may lead you to believe that they would be more common than non-self-pollinating primroses. However, not only are they less common, but they're actively rare among primroses.

So, to relate this back to the comparisons, we have a difference that suggests one outcome (higher average seed production → more common), but then a difference that runs counter to that expectation (much less common/rare).

To explain a difference such as this, we generally need to find another difference. And here, since the two types of primroses are "indistinguishable" outside of their seeds, the correct answer will need to establish something different about the seeds of the two types of primroses that suggests the non-self-pollinating primroses would be common compared to the self-pollinating ones.

Answer Explanation:
This answer highlights a difference between the seeds of the two types of primroses relevant to the paradox. If the non-self-pollinating primroses have seeds that are more likely to germinate, then that explains why they would be more common than the self-pollinating ones. In establishing a relevant difference between the seeds of the two types of primroses that explains why one is more common than the other, this answer resolves the paradox and is correct.

Key Takeaway:
Paradox questions that rely on comparisons will frequently have comparative answers. Here, the paradox involved an unexpected difference between two things, and the correct answer brought up a relevant difference to explain it.

Incorrect. First, this answer establishes a similarity. Second, that similarity is between self-pollinating primroses in different areas, not between self- and non-self-pollinating primroses.

Incorrect. This is true of both self- and non-self-pollinating primroses, so it doesn't do anything to resolve the paradox.

Incorrect. First, if anything, this answer brings up a similarity between the two types of primroses, as insects help both with pollination. That said, if anything, this answer raises ways that self-pollinating primroses would see more pollination at a time when non-self-pollinating primroses would, as well, making the paradox of the relative rarity worse.