Adult female rats who have never before encountered rat pups

Question

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.
(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.
(C) Female rats that have given birth are more affected by olfactory cues than are female rats that have never given birth.
(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.
(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.

GMATNinja · Accepted Answer

We need something that explains why the amount of time it takes for adult female rats to start showing maternal behaviors "can be considerably shortened by disabling the female's sense of smell or by removing the scent-producing glands of the pup." So we need to compare adult females who CAN pick up the scent of the pups to adult females who CANNOT pick up the scent of the pups.

We are not trying to explain a difference between female rats who  have  given birth and female rats who  have never  given birth. Instead, we are trying to compare adult females who CAN pick up on the scent of the pups to adult females who CANNOT pickup on the scent of the pups. Choice (D) does not explain why the group who cannot pick up the scent shows maternal behaviors in a shorter amount of time. Thus, (D) should be eliminated.

Ah ha... normally, an adult female rat will start showing maternal interest in a pup that she did not bear after about a week. If this maternal interest is normally  inhibited  by the odor of the pup, we can infer that the time would be shortened if the female could NOT smell the odor of the pup.

For example, if the female's sense of smell has been disabled or if the scent-producing glands of the pup have been removed, the adult female will not be able to smell the pup. This would remove a factor that, according to choice (E), normally  inhibits  maternal interest. As a result, those maternal interests would be developed in LESS time than usual.

Choice (E) explains the difference described in the passage and is the best answer.

I hope that helps!

curtis0063 · Answer

This question took me a lot of time for review. So I provide my reasoning here for someone who stuck with brain.

Premise: female rates encountered pups --> trigger maternal behaviors after 7 days
Condition: disable sense or removing glands --> period of triggering will be shortened (less than 7 days)

(E) provide us this connection: removed odor --> trigger maternal interest

stevegt · Answer

why does the odor INHIBITS the interest? this passage reads: it is the odor that STIMULATES the interest...

GMATBLACKBELT · Answer

E.

We need something to connect the two statements above. This connection preferably needs to be explained by an odor given off by the pups. This odor or scent has something to do with why the females do not show maternal behavior for at least seven days.

vineetgupta · Answer

The author never says that odor stimulates the interest...may be the interest was developed by something else(cute rats may be)...but this interest is affected by the odor in an adverse manner.

anonymousegmat · Answer

you are mentally filling in the wrong gaps for this question without realizing it. The test takers employ psychologists and all sorts of PhD's just for this reason. nowhere did it say odor stimulates interest.

yes, common sense and experience tells us the odor stimulates interest if the rat pup is the actual offspring of the mommy rat. your brain filled in this gap for you, which is why you got it wrong. The question was designed just for this purpose.

the stimulus tells us that odor inhibits maternal instincts if it isn't the rats actual child. over time, a rat will take care offspring that isn't hers. take the odor or the ability to smell away, and it will do it quicker. which is why E is the answer.

zoezhuyan · Answer

does anyone think that "the period" stands for "seven days", like me ?

when I read this question, I am totally mess because I cannot understand the logic of the prompt , if shorten "seven days", then damage the link between smell and odor.

while E states that no odor, no maternal behavior.

what a poor verbal

Hadrienlbb · Answer

Hi everyone. I understand how E connects both statements from the passage, and how other answer choices are unsatisfactory.

However, can someone help me understand why I should not be bothered by the following:

If, according to E, the development of a female rat's maternal interest is  inhibited  by the odor, then how does one explain that after being confined with a pup for about seven days it starts showing maternal behavior? 
My feeling is that in science, and in English in general, the meaning of the verb "to inhibit" is quite strict. So unless the rat's sense of smell is disable / the scent-producing glands of the pup are removed, there should be no development of maternal interest whatsoever.

Thanks for your help!

GMATNinjaTwo · Answer

"Inhibit" can mean to  hinder  an action or process. For example: "Refrigeration helps to inhibit the growth of bacteria in food." That doesn't mean that refrigeration completely  stops  the growth of bacteria, but it slows down the process.

Similarly, the odor doesn't STOP the female from developing maternal interest, but it does slow the process (i.e. seven days instead of less than seven days).

DurgeshNandini · Answer

I cannot understand the question itself...what exactly is the contrast described?

GMATNinja · Answer

The passage contrasts two groups of adult female rats who have never encountered rat pups. Rats in these groups are tested to see how long it takes them to develop maternal instincts toward a pup that is confined with them. Here is a breakdown of each group:

Group 1: 
  Normal female rats confined with normal rat pups. 
 Time to show maternal behaviors: "about seven days."

Group 2: 
  Female rats who have had their sense of smell disabled confined with normal rat pups, OR normal female rats placed with rat pups who have had their scent-producing glands removed. In other words, female rats who cannot smell the rat pups. 
 Time to show maternal behaviors: considerably shorter than seven days.

To answer the question, we need to find a hypothesis that explains why the rats in Group 2 take a shorter amount of time to start showing maternal behaviors than the rats in Group 1.

Hopefully that's enough to get you headed in the right direction?

sayan640 · Answer

The contrast is :- 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 shortened if adult female rats don't get the smell of the pups.

Option C and D are out because we are talking about the "Adult female rats who have never before encountered rat pups" in the passage and not "Female rats that have given birth".

"Female rats that have given birth" must have encountered rat pups before. So irrelevant for our discussion.

Option B is also out because it talks about "a female rat that did not bear them." We are talking about the "Adult female rats who have never before encountered rat pups" in the passage.

"a female rat that did not bear them" may have borne some other pups and may have encountered rat pups and hence irrelevant to our discussion.

Option A does not explain the shortening of the period.

Option E explains and gives a reason stating that "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."
If the female dont get the odor of the pup , they develop maternal interest quickly.

Option E is the answer.
Please give me kudo s if you liked my explanation.

generis   GMATNinja   VeritasKarishma   chetan2u 
Is my explanation correct ?

jabhatta2 · Answer

I chose (B) thinking of the argument this way

So, if you disable the sense of smell, these adult female rats (that did not bear these rat pups) will find it harder to realize they themselves DID NOT produce these rat pups.

Put, another way - these adult female rats (that did not bear these rat pups) will find it harder to figure out if they themselves are the real mother of these cubs or not the real mother of these cubs.

Thus if these adult female rats (that did not bear these rat pups) now might think of these rat pups as their own kids

Given these adult female rats (that did not bear these rat pups) might mistake these rat pups as their own kds -- these adult female rats (that did not bear these rat pups) will obviously show maternal behavior faster.

jabhatta2 · Answer

JDs note -- i think there ARE MANY MANY ASSUMPTION in this 
The purples are asumptions that you cannot justify

Just because you happen to be the mother of kids -- will you show maternal instincts faster ? that may be the case for humans but maybe not for rats. One cant say

Also, another mistake is assuming that 'smell' is the way RATS can figure out if they are the mothers of cubs or not. Maybe its not smell that RATS use to figure out

bibliophileank · Answer

"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."

Safe to Infer - SMELL is the connecting link between female rats and pups. And with this sense of small, it takes 7 days for female rat to develop a maternal interest in pup.
Hence, if this SMELL factor be removed, she could develop maternal interest earlier.

This helps in justifying contrast as if there was no odor of pup - her maternal interest would've ignited earlier than 7 days.

Hope this helps!

shailendra010786 · Answer

Gmat  Ninja , Veritas Karishma ,AndrewN can anybody tell Why option B is wrong?

GMATNinja · Answer

(B) tells us that because the rat pups are close to a female rat who is not their mom, they are smellier than they would otherwise be. But that in itself doesn't explain the behavior of the female rats -- why do they act differently when they can smell the pups? Just knowing that the pups are more smelly than usual doesn't give us any hints.

By contrast, (E) tells us  exactly  why the female rats behave the way they do -- their maternal instinct is inhibited by the smell of the pups. So, when that smell is turned down, they act maternally more quickly.

(B) is out because it doesn't explain the female rats' behavior, and (E) is the correct answer.

I hope that helps!

VerbalBot · Answer

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Adult female rats who have never before encountered rat pups

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Adult female rats who have never before encountered rat pups

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