Logical reasoning PrepTest 153 · Section 2 · Question 18

Incorrect. This isn't relevant to the hypothesis here, which is only about mature vs. young seals.

Incorrect. Again, we really don't care about any prey species other than harbor seals. (Sorry, fish.) The relevant difference is between younger and older seals, not seals and fish.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
Some killer whales (orcas) eat seals, and others don't. These separate groups of killer whales also vocalize in different "dialects," which harbor seals understand and use to avoid the seal-eating clans. Scientists think that baby seals avoid all killer whales, but over time they learn to use dialect to identify which individuals are safe to be around.

Strategy Overview:
The prompt tells us to strengthen the biologists' hypothesis, so make sure you've identified that first. (It's the bit about baby seals developing their differentiation between different killer whales over time.) It's not causal, so move on to looking for some missing support that you might be able to provide by adding a new premise to the argument.

Answer Anticipation:
How might we strengthen that hypothesis? Well, one way would be to prove that harbor seals are capable of learning new information about a group of killer whales and then recognizing that group based on their dialect. And scientific hypotheses are usually tested with some kind of experiment.

Answer Explanation:
This comes in a little bit of an unexpected form, but it fits our anticipation. It's an experiment, and it shows that the harbor seals are memorizing "safe" dialects over time. If they are confronted with the dialect of unknown fish-eating whales, and react with fear, they must have learned over time to trust the fish-eating whales they know personally. Presto, correct answer.

Key Takeaway:
Some strengthen or weaken questions will ask you specifically about a scientific hypothesis. These are no different from standard S/W questions, except that your answer is more likely to come in the form of an experiment or study result. Avoid trap answers that are come in the right form—some kind of test of a hypothesis—but wouldn't actually be able to support or disprove the specific hypothesis you're looking to strengthen/weaken.

Incorrect. Just like we don't care about other prey, we also don't care about other predators. It's the learning as seals mature that's important to the hypothesis, not how they relate to other predators.

Incorrect. This is a little bit tempting, because it shows harbor seals learning, but it's not the kind of learning we were looking for. One harbor seal at a time learning to fear fish-eating killer whales based on their dialect does not constitute proof that young seals in general learn to trust fish-eating killer whales based on their dialect.