PT157 S3 Q15 ExplanationAnts sometimes live in hollow places

Answer choices, explained

1. A

   No Impact4% picked this

   Microscopic organisms that are present in the orchids’ roots break down the organic matter stored

   Microscopic organisms breaking down the organic matter addresses the mechanism of the provided explanation, not an alternative one. We need a different causal story, not more detail about the existing one.

   4%
2. B

   No Impact9% picked this

   The nutrients present in the organic matter stored by the ants are the same as those present in the soil in

   If the ant-deposited nutrients are the same as those in the surrounding soil, this weakens the provided explanation but does not offer an alternative. We need a different reason for the health correlation, not a reason to doubt the current one.

   9%
3. C

   Correct87% picked this

   The ants that live in hollow places in the roots of orchids prey on an insect species whose

   Why this is right

   This provides a completely different causal explanation. The ants prey on insects that eat orchid roots. If the ants protect the orchids from root-eating insects, orchids with ants would be healthier — not because of extra nutrients, but because their roots are not being eaten. This is a different mechanism connecting ants to orchid health: pest control rather than nutrient supplementation.

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   87%
4. D

   No Impact1% picked this

   The ants that live in hollow places in the roots of orchids do not play a role in pollinating

   The ants not playing a role in pollination has no causal power. We need an explanation where ants do something beneficial. Saying the ants do not do something provides no alternative explanation for the health correlation.

   1%
5. E

   Opposite, if anything1% picked this

   Most plant species whose roots, stems, or leaves harbor insects are more prone to disease and rot

   If most insect-harboring plants are more prone to disease, this suggests ants should make orchids less healthy, not more. This deepens the puzzle rather than explaining it, and potentially weakens any explanation involving ants benefiting orchids.

   1%