Reading ComprehensionDifficulty: Medium

PT105 S3 P1 Q6 Explanation

Invertebrate Schooling

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsInferenceScience

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Passage

Until recently, many biologists believed that invertebrate "schools" were actually transient assemblages, brought together by wind, currents, waves, or common food sources. Jellyfish groupings, for example, cannot be described as schools—cohesive social units whose members are evenly spaced and face the same way. However, recent research has found numerous cases in which such massive numbers that they provide abundant food for fish, seabirds, and whales.

Like schooling fish, invertebrates with sufficient mobility to school will swim in positions that are consistent relative to fellow school members, and are neither directly above nor directly below a neighbor. The internal structure of such a school dramatically with the advent of a predator.

Since schooling is an active behavior, researchers assume that it must bring important benefits. True, schooling would appear to make animals more visible and attractive to predators. However, schooling leaves vast tracts of empty water, thereby reducing a predator's chances of picking up the school's trail. A large group maintains surveillance better some of the invertebrates, any individual school member has a good probability of escaping.

In addition to conferring passive advantages, schooling permits the use of more active defense mechanisms. When a predator is sighted, the school compacts, so that a predator's senses may be unable to resolve individuals, or so that the school can execute escape maneuvers, such as freezing to foil predators that hunt by predators threaten the margin, school members may put on dazzling and confusing displays of synchronized swimming.

Schooling may also enable invertebrates to locate food—when one group member finds food, other members observe its behavior and flock to the food source. On the other hand, competition within the school for food may be intense: some mysids circle around to the back of the school in order to eat food of a school; if that size is exceeded, some of the animals will join another school.

What this question is testing

Inference

Your task

Find what must be true based on what the passage or stimulus states.

Common trap

Answers that are plausible or likely but not actually guaranteed by the text.

Winning move

Keep only the choice the statements fully support — eliminate anything that requires an extra assumption.

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

The question
6.

It can be inferred from the passage that if cannibalism were occurring in a large school of crustaceans, an individual crustacean

Answer choices

  1. Unrelated to Goal13% picked this

    try to stay at the edge of the school in order

    We're looking for something like, "... it would realize this school is too big and join another school". Nowhere in the passage does it say that "by staying on the edge you can obtain food". It only said at one point that when food is scarce, some of the critters that find food will swim to the back to eat it privately, so their schoolmates don't glare at them like, "Did you bring enough to share with the whole class?"

  2. Contradicted2% picked this

    be more likely to be eaten if it were

    We were told that when cannibalism occurs, it's the adults who feed on the young (the not-fully grown). You'd be more likely to be eaten if you were not fully grown.

  3. Correct73% picked this

    be unlikely to join that particular

    Why this is right

    We're looking for something like, "... it would realize this school is too big and join another school". This is our best match.

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

  4. Unrelated to Goal5% picked this

    try to follow at the back of the school in order

    We're looking for something like, "... it would realize this school is too big and join another school". Nowhere in the passage does it say that "by staying near the back you can escape predators", nor does this answer about predators have anything to do with cannibalism within the school.

  5. Unrelated to Goal7% picked this

    try to confuse school members by executing complex

    We're looking for something like, "... it would realize this school is too big and join another school", and this answer sounds nothing like that. We might think to ourselves, "One of the defensive maneuvers that schools perform is executing complex swimming maneuvers. So maybe if an individual crustacean rolled up to a crustacean school where some members were eating other members, they would click into doing this defensive maneuver to avoid being cannibalized." But this is a much more exotic, unsupported guess. We are told in the final sentence of the passage what happens once cannibalism arises: some of the animals will join another school.

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