I solved this in 1:12, so that would probably mean 1:40 on an actual exam. I guess I used pre-thinking to guide my approach but not entirely. The thing to keep in mind is the specific question being asked. Keep in mind the players in the study. The Adults female rats (who have never before encountered rat pups) and pup(s). I know it may seem trivial, but if the test-writers went out of their way to write it, it was for a reason. Every single word is probably deliberated by these people after all. Anyway, in this question, something about the FEMALE’s sense of smell or REMOVAL of the scent-producing glands of the pup has some EFFECT on the maternal behaviour. Keep this in mind when going through the answers.
Adult female rats who have never before encountered rat pups will start to show maternal behaviors after being confined with a pup for about seven days. This period can be considerably shortened by disabling the female's sense of smell or by removing the scent-producing glands of the pup.
Which of the following hypotheses best explains the contrast described above?
(A) The sense of smell in adult female rats is more acute than that in rat pups.
I confess I ran through the answers on my initial run and picked the right one not by eliminating the wrong choices but by simply choosing the right one. It’s not the best strategy, I daresay. But perhaps sometimes it’s a lot easier and you may want to calculate the RISK of getting an answer choice right in a very short amount of time VS taking longer with not much difference in accuracy. This answer choice is wrong simply because REGARDLESS of whether the sense of smell was more acute in EITHER rat pups or the females, it doesn’t EXPLAIN anything specifically. Does a stronger sense of smell give rise to fear, maternal instinct, irritability?
(B) The amount of scent produced by rat pups increases when they are in the presence of a female rat that did not bear them.
Even
if the amount of scent produced increases, so what? What does that explain? This is a “create a fantasy” answer choice. Eliminate. We need something more specific that links behaviour with scent.
(C) Female rats that have given birth are more affected by olfactory cues than are female rats that have never given birth.
I eliminated this more on recognition. But, looking at it closely, we can see it is irrelevant for bringing in a 3rd party that we have no data on. Female rats that have given birth and their behavior with pups not their own is a completely different grouping to simply throw in with any credibility at this point. Without data it is difficult to say how Female rates (who are mothers) act with pups not their own.
(D) A female rat that has given birth shows maternal behavior toward rat pups that she did not bear more quickly than does a female rat that has never given birth.
Like in (C), this one is out. You can’t simply bring a third party to this group without some specific data. Remember the question, people. It’s asking to explain the contrast above. A lot of these are not SO wrong you may be absolutely sure you should eliminate but you should be having some reservations about them all.
(E) The development of a female rat's maternal interest in a rat pup that she did not bear is inhibited by the odor of the pup.
Yes, yes. I was looking for this for the beginning. There was something about the scent of the pup that changed the female rat’s behaviour. This links the maternal interest directly with the odor. Compared with all the other answer choices this is clearly the best.
_________________
www.gmatknight.com | Online GMAT Tutoring - Verbal 99% V48 - Q50 [Section Bests] - quick tip: there's a free auto-booking feature on the gmatknight site for a 15-min consult :)