Logical Reasoning

PT150 · S3 · Q17 Since mosquito larvae are aquatic

A free, expert breakdown of this official LSAT Logical Reasoning question.

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Since mosquito larvae are aquatic, outbreaks of mosquito- borne diseases typically increase after extended periods of wet weather.

Background

Mosquito larvae are aquatic, so outbreaks of mosquito diseases typically go up after long periods of wet weather.

Surprise / Exception

If the mosquito breeds in a wetland habitat, then the outbreaks of mosquito diseases tends to go up after a drought.

Evaluate / Goal

We need something different about mosquitoes who breed in wetlands that would explain why they seem to proliferate after periods of drought.

17.

Which one of the following, if true, most helps to resolve the apparent discrepancy described above?

  1. The use of insecticides is

    Unrelated to Drought

    If you can't use pesticides in a wetland habitat, then you would potentially end up with more mosquitoes in a wetland habitat. But insecticides have no connection to drought, and we need a way to explain why there's an explosion of mosquitoes after a drought, rather than after wet weather.

    5% picked this

  2. Human populations tend to be

    Unrelated to Drought

    If you don't have humans near a wetland habitat, is that a good thing or a bad thing for mosquito populations? The fact that I'm not sure should warn us that there's no common sense knowledge to use here. Obviously mosquitoes bite humans, but does the presence of human populations make it more or less likely that local mosquitoes would thrive? More importantly, human populations have no connection to drought, and we need a way to explain why there's an explosion of mosquitoes after a drought, rather than after wet weather.

    3% picked this

  3. Correct

    Wetland habitats contain numerous aquatic

    Why this is right

    Since mosquito larvae (babies) are aquatic, they hatch in water. If they live in a wetland habitat, where there are aquatic predators, then the predators eat a lot of the larvae and reduce the overall mosquito population. During a drought, though, water dries up, and so the populations of aquatic insects would go down. If the population of mosquito larvae's predators is lower, than more mosquito babies will grow up, spread their wings, and get out in there in the real world to spread some diseases.

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

    71% picked this

  4. Wetland habitats host a wider

    Unrelated to Drought

    A wider variety of mosquito species has no connection to drought, so it doesn't give us a way to explain how drought makes the mosquito population increase.

    11% picked this

  5. Periods of drought in wetland

    Unclear Impact

    This answer has a direct tie-in to drought. When there's a drought, there will be more plants growing. But do we have a common sense way to get from "more plants growing" to "more mosquitoes / more disease outbreaks"? No. In the correct answer, we had "when there's a drought, it will negatively impact aquatic insects that prey on mosquito larvae". There, we have a common sense way to get from impact of a drought (mosquito predators disappear) to the idea of "more mosquitoes / more disease outbreaks".

    10% picked this

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free