PrepTest 84, Section 3, Question 17
Since mosquito larvae are aquatic, outbreaks of mosquito-borne diseases typically increase after extended periods of wet weather. An exception to this generalization, however, occurs in areas where mosquitoes breed primarily in wetland habitats. In these areas, outbreaks of mosquito-borne diseases are worse after periods of drought.
Since mosquito larvae are aquatic, outbreaks of mosquito-borne diseases typically increase after extended periods of wet weather. An exception to this generalization, however, occurs in areas where mosquitoes breed primarily in wetland habitats. In these areas, outbreaks of mosquito-borne diseases are worse after periods of drought.
Since mosquito larvae are aquatic, outbreaks of mosquito-borne diseases typically increase after extended periods of wet weather. An exception to this generalization, however, occurs in areas where mosquitoes breed primarily in wetland habitats. In these areas, outbreaks of mosquito-borne diseases are worse after periods of drought.
Since mosquito larvae are aquatic, outbreaks of mosquito-borne diseases typically increase after extended periods of wet weather. An exception to this generalization, however, occurs in areas where mosquitoes breed primarily in wetland habitats. In these areas, outbreaks of mosquito-borne diseases are worse after periods of drought.
Which one of the following, if true, most helps to resolve the apparent discrepancy described above?
The use of insecticides is typically prohibited in wetland habitats.
Human populations tend to be sparse in areas near wetland habitats.
Wetland habitats contain numerous aquatic insects that prey on mosquito larvae.
Wetland habitats host a wider variety of mosquito species than do other areas where mosquitoes breed.
Periods of drought in wetland habitats create conditions conducive to the emergence of new plant growth.
Explanations
For starters, this isn't an argument, just some fun facts about mosquito-based illness patterns.
We're provided some incompatible circumstances.
(1) Mosquito larvae are aquatic. I.e., they breed in wet places. (2) Mosquito-borne disease generally increases following heavy wet weather. (3) Except in one case: wetlands, wherein mosquito-borne disease increases following a drought.
It's a Paradox question, so we need to reconcile these seemingly incompatible facts. That is, why might mosquito-borne disease increase during wetland droughts?
I suspect it will have to do with something about the wetlands environment—that, even during drought, there's sufficient water for the mosquito to continue breeding. Perhaps they breed more when there's less water to overcompensate?
Let's see.
Nah. This would explain why there'd be more mosquitoes in wetlands generally speaking, but it doesn't help us understand why disease rates increase during droughts.
Nope. I'm sure this is true, but it doesn't explain why disease rates would increase in wetland areas during droughts.
Bingo. Not exactly what I predicted, but correct nonetheless. If this is true, then during droughts—when there may well be enough water still for mosquitoes to breed—the mosquitoes' natural predators might die off or hide to conserve water, resulting in larger mosquito populations.
Nah. If anything, this makes matters worse than in the passage. Even if there are more mosquitoes in wetlands, why would their disease rates increase during droughts?
No. This focuses on an entirely tangential issue. If droughts lead to new plant growth in wetlands during droughts, that's all well and fine, but it tells me nothing about mosquitoes.
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