If newly hatched tobacco hornworms

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

TopicsStrengthen

Keep going in LSAT Lab

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

Free to start

Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Stimulus

If newly hatched tobacco hornworms in nature first feed on plants from the nightshade family, they will not eat leaves from any other plants thereafter. However, tobacco hornworms will feed on other sorts of plants if they feed on plants other than nightshades just after hatching. To explain this behavior, scientists hypothesize found only in nightshades, and after this habituation nothing without indioside D tastes good.

What this question is testing

Strengthen

Your task

Find the choice that makes the argument's conclusion more likely to be true.

Common trap

Answers that are consistent with the argument but add no real support, or that strengthen a claim the argument doesn't make.

Winning move

Locate the gap between evidence and conclusion, then pick the choice that closes it.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question

Which one of the following, if true, adds the most support for

Answer choices

Irrelevant Distinction4% picked this
Tobacco hornworms that first fed on nightshade leaves show no preference for any one variety of nightshade
This choice discusses different varieties of nightshade and their preference, which is irrelevant. The argument is focused on the habituation to a specific chemical in nightshade, not on types of nightshade.
4%
Correct92% picked this
If taste receptors are removed from tobacco hornworms that first fed on nightshade leaves, those hornworms will subsequently
Why this is right
This choice presents a "no cause, no effect" scenario: if hornworms lack taste receptors for the nightshade chemical, they will eat other plants. The author's causal story was 1. eat nightshade 2. insidio D changes taste receptors 3. won't eat any other plants This supports that story by showing that if you don't have #2, you don't get #3.
Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.
92%
No Impact1% picked this
Tobacco hornworm eggs are most commonly laid on
The location where hornworm eggs are laid doesn't address why hornworms develop a taste preference once they start with nightshade, making it irrelevant to the central causal claim.
1%
Weakens (if anything)0% picked this
Indioside D is not the only chemical that occurs only in
This choice introduces other chemicals in nightshade, which means it's opening up the possibility for alternate explanations for the taste receptor habituation. "Ooh, maybe it's not insidio D. Maybe it's some other chemical that gets hornworms hooked on nightshade."
0%
No Impact2% picked this
The taste receptors of the tobacco hornworm have physiological reactions to several
This is a very weak claim, one we would probably assume is true of taste buds in any creature (that it can react to several natural chemicals). And it doesn't speak to any part of the author's causal chain for how hornwoods get habituated to nightshade's unique chemical.
2%

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