Until recently, zoologists believed that all species of phocids (true

Question

Until recently, zoologists believed that all species of phocids (true seals), a pinniped family, use a different maternal strategy than do otariids (fur seals and sea lions), another pinniped family. Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Throughout the rest of the lactation (milk production) period, which lasts from 4 months to 3 years depending on the species, mother otariids alternately forage at sea, where they replenish their fat stores, and nurse their young at breeding sites. Zoologists had assumed that females of all phocids species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species. However, recent studies on harbor seals, a phocids species, found that lactating females commenced foraging approximately 6 days after giving birth and on average made 7 foraging trips during the remainder of their 24-day lactation period.

The maternal strategy evolved by harbor seals may have to do with their small size and the large proportion of their fat stores depleted in lactation. Harbor seals are small compared with other phocids species such as grey seals, northern elephant seals, and hooded seals, all of which are known to fast for the entire lactation period. Studies show that mother seals of these species use respectively 84 percent, 58 percent, and 33 percent of their fat stores during lactation. By comparison, harbor seals use 80 percent of their fat stores in just the first 19 days of lactation, even though they occasionally feed during this period. Since such a large proportion of their fat stores is exhausted despite feeding, mother harbor seals clearly cannot support all of lactation using only energy stored before giving birth. Though smaller than many other phocids, harbor seals are similar in size to most otariids. In addition, there is already some evidence suggesting that the ringed seal, a phocids species that is similar in size to the harbor seal, may also use a maternal foraging strategy.   1 
 1. It can be inferred from the passage that the females of all phocids species differ from the females of all otariid species in that the female phocids

A. have shorter lactation periods 
B. consume more food during lactation 
C. consume a higher proportion of fat stores 
D. forage for food occasionally during their lactation periods 
E. deplete a smaller percentage of their fat stores during their lactation periods

2 
 2. The primary purpose of the passage is to

A. present evidence that several phocids species use the maternal fasting strategy 
B. explain why the maternal strategy typically used by phocids is different from the maternal strategy used by otariids 
C. argue that zoologists 'current understanding of harbor seals' maternal strategy is incorrect 
D. describe an unexpected behavior observed in harbor seals and propose an explanation that may account for the behavior 
E. describe evidence concerning the maternal strategy of the harbor seal and suggest that the harbor seal belongs to the otariid rather than to the phocids family

3 
 3. According to the passage, until recently zoologists believed which of the following about all phocids mothers?

A. Their fasting periods after giving birth were typically shorter than those of otariids. 
B. Their lactation periods were generally as long as those of comparably sized otariids. 
C. They acquired only moderate energy stores in the form of blubber before arriving at breeding sites. 
D. They depleted less than a third of their stored body fat during lactation. 
E. They replenished their fat stores only after their lactation period ended.

4 
 4. The author of the passage mentions ringed seals most probably in order to

A. provide an example of a phocid species that fasts throughout its entire lactation period 
B. provide an example of a phocid species whose maternal strategy is typical of phocid species 
C. provide an example of a phocid species that may deplete an even higher proportion of its fat stores during lactation than harbor seals do 
D. support the assertion that harbor seals are smaller than many other phocids 
E. support the assertion that harbor seals' maternal strategy may be related to their small size.

GMATNinja · Accepted Answer

This passage is supremely good at using technical details to distract us. One really important thing to keep in mind on any GMAT RC passage: you don't need any prior knowledge to nail these passages. If you have no idea what a pinniped or a phocid or a otariid is, no problem -- the passage defines them for you.

So let's break down the purpose of each paragraph and avoid getting bogged down in details whenever we can.

Paragraph 1 
 
 There are two kinds of pinnipeds: phocids (let's call them Group P) and otariids (let's call them Group O). 
 Group O uses a foraging strategy, while Group P uses a fasting strategy. 
 However, recent studies show that harbor seals (which belong to Group P) do forage as well.

What's the purpose of Paragraph 1?  To identify how the maternal strategies of Group O and Group P differ, then present the harbor seal as an exception to the strategy of Group P.

Paragraph 2 
 
 Harbor seals from Group P might forage because of their small size and rate of fat store depletion.  
 There is evidence to support this explanation. 
 The behavior of ringed seals (also in Group P) may also support this explanation

What's the purpose of Paragraph 2?  To explain why the harbor seal is an exception (their smaller size and high fat depletion rate), and provide evidence to support this explanation.

Now that we've gotten a handle on the structure and meaning of each paragraph, we see that author wrote this passage  to explain how and why harbor seals don't follow the maternal strategies of their group.  Let's eliminate answer choices that don't match, and search for the one choice that gets closest to what we've read.

This choice is wrong about  why  the author is writing the passage (it's not simply to present evidence). It's also wrong about the author's primary focus (it's not several species from Group P that illustrate that group's strategy, but one species from Group P that deviates from that group's strategy). Eliminate (A).

This choice only captures a portion of Paragraph 1. We're looking for the purpose of the passage as a whole. Eliminate (B).

The author never argues that zoologists' understanding of harbors seals' strategy is  incorrect . Eliminate (C).

This matches our understanding the passage almost exactly. Paragraph 1 tells us the expected behavior, then informs us that harbor seals' behavior is unexpected. Paragraph 2 presents an explanation (size and rate of fat depletion) for harbor seals' behavior. Let's keep (D) around and see if (E) is any better.

Is the author's main point that the harbor seal  belongs to Group O, not Group P?  In other words: Did the author write this passage to tell us that we're putting harbor seals in the wrong group? No. We haven't seen any language from the author suggesting that this is the case. In fact, the author consistently refers to harbor seals and even ringed seals as  phocids , without ever suggesting that they should be categorized differently.

The author structured this passage to help us understand the maternal strategies of Group O and Group P, then explain why harbor seals use a strategy that doesn't match their group's. This is not the same as telling us that harbor seals belong to a different group altogether. That's why we eliminate (E) and keep (D) as the best answer choice.

I hope this helps you foster a seal -- I mean, foster  great reading habits when it comes to identifying the primary purpose !

ChrisLele · Answer

For this passage, the answers are in the details. A good strategy, like with most GMAT RC passages, is to create an outline in your head, encapsulating the main points of the passage: OTs forage throughout lactation period (last up to 3 yrs) PH. are larger and were thought to fast during their much shorter lactation periods. Harbor seal, PH., challenges this traditional view, since it forages during lactation. Possible theory: the harbor seal is much smaller than average PH, which have lots of blubber and can fast, and is similar in size to OT, which don't have much fat stores. Size is connected to foraging behavior and lactation. Now to the questions

1) Otariids have a lactation period that is "4 months to 3 years"; phocines have one that "lasts from 4 and 50 days. Therefore, (A). 2) Harbor seals feed during lactation, which is uncommon in phocines (the second passage contrasts the grey seal, a phocine, which fasts throughout lactation). The point of the passage is to account for this behavior (the theory is that size plays a major role in lactation and foraging). The first paragraph mainly provides context for the difference between the two seal species in this regard. (C) shifts the focus to current theories on harbor seals and how these theories are incorrect. The point of the passage is that the harbor seal represents an instance that should lead experts to reconsider their views on phocine as a whole, when it comes to foraging and lactation. (E) goes too far since the passage never implies that the harbor seals belongs to the otariids, just that its behavior is atypical for a phocine, and therefore that not all phocine follow a pattern similar to that of the grey seal. 3) The last part of the first paragraph points to the idea that zoologists thought that all phocines fast throughout lactation, "fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period". The "however" clues us into the fact that the behavior of the harbor seal changes this view. 4) The last part of the second paragraph arrives at the conclusion that the foraging behavior of the harbor seal is related to its size. To further back up this claim, the passage mentions the "ring seal", another small phocine that has similar foraging behavior during lactation as the harbor seal. The phrase "maternal strategy" represents foraging and lactation behavior. Hope that helps

DmitryFarberMPrep · Answer

2. The primary purpose of the passage is to

The key to answering Main Point questions is to read for that point from the beginning. As you read, you should be asking yourself "Why did the author write this? What is the point?" Before you get to a single question, you should be able to state to yourself not only what the author's overall point is, but also how each paragraph relates to that point. ("The point here is that contrary to zoologists' previous beliefs, not all P's differ in strategy from O's. Harbor seals (P's) forage, just like O's do! The first paragraph explains the distinction and the previous belief, and reveals that harbor seals provide an exception. The second paragraph looks at possible explanations for this exception.")

What you  don't  have to do is memorize/digest all the technical detail. Read for the big picture and come back to the details as required by the questions. Even on passages that don't have a Main Point question, you'll benefit greatly from having a high-level understanding of the passage as a whole.

Kurtosis · Answer

6 min 18 secs - Answered all questions correctly.

1) It can be inferred from the passage that the females of all phocid species differ from the females of all otariid species in that the female phocids

Lactation period of otarids - 4 months to 3 yrs
Lactation period of phocids - 4 days to 50 days

Answer: A

2) The primary purpose of the passage is to

The passage first distinguishes between the maternal strategy of otarids and phocids. Next, the passage takes up the example of harbor seals, a phocid which does not follow the phocid maternal strategy. The passage explains possible reasons for the behavior exhibited by harbor seals.

Answer: D

3) According to the passage, until recently zoologists believed which of the following about all phocid mothers?

Refer to the lines: "Zoologists had assumed that females of all phocid species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites,   fast throughout the entire lactation period  , which lasts from 4 to 50 days depending on the species."

Answer: E

4) The author of the passage mentions ringed seals most probably in order to

Refer to the line: " In addition, there is already some evidence suggesting that the ringed seal,   a phocid species that is similar in size to the harbor seal  , may also use a maternal foraging strategy."

Answer: E

Arro44 · Answer

This passage is great practice, especially because it is among the most boring things I have ever read.

Full of detail, difficult vocabular about a farily unexiciting topic... a great example of a challenging Gmat RC passage.

Srija221 · Answer

Can anyone please explain question no 3? 
It is asking that what the zoologists had assumed about the mother of all phocids species? 
So they had assumed that the mother phocids uses fasting strategy, where the fast during the entire lactation period! So how is option E correct?

Posted from my mobile device

GMATNinja · Answer

Yes, the researchers had assumed that all phocid mothers used a fasting strategy, which means that they did not eat at all during the lactation period. The phocid moms did this by acquiring a large amount of fat BEFORE giving birth, and then losing that fat while lactating. AFTER the lactation period, they would be free to forage again and replenish their fat stores.

This is exactly what (E) is telling us:
 
The researchers believed that phocid mothers built up a lot of fat, lost a large proportion of that fat while lactating and not eating anything, and then replenished their fat stores after the lactation period ended. (E) is the correct answer to question #3.

I hope that helps!

kittle · Answer

GMATNinja  - enjoyed your explanation of the passage. How to not get bogged down while attempting such passages during the real exam? It is a fairly simple passage if one has an ability to steer away from those technical jargons that the passage is throwing at him/her. Please suggest any tips.

GMATNinja · Answer

The short answer is to make sure you are reading for purpose and structure, and not obsessing over details. For more on that, please check out our  RC guide for beginners  if you haven't already, or the RC videos listed  here .

I hope those help a bit!

BLM · Answer

For Q1, as seen in the paasage:
Mother otariids use a foraging strategy. They acquire moderate energy stores in the form of blubber before arriving at breeding sites and then fast for 5 to 11 days after birth. Zoologists had assumed that females of all phocids species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species.

How is C wrong when it is clear that phocids accumulate large energy stores whereas otariids acquire moderate energy stores in the form of blubber before arriving at breeding sites.
I understand A is also stated.

Kindly help!

MartyMurray · Answer

Here's the question:

1. It can be inferred from the passage that the females of all phocids species differ from the females of all otariid species in that the female phocids

Notice that the question is about "the females of ALL phocids species" and "the females of ALL otariid species."

Here's choice (C).

C. consume a higher proportion of fat stores

Now, look at what you quoted:

Zoologists  had assumed  that females of all phocids species, by contrast, use a fasting strategy in which mother phocids, having accumulated large energy stores before they arrive at breeding sites, fast throughout the entire lactation period, which lasts from 4 to 50 days depending on the species.

So, the passage says that zoologists HAD ASSUMED that females of all phocids species fast throughout the entire lactation period. Notice details like that one is key to getting RC questions correct.

Then, it says the following:

However, recent studies on harbor seals, a phocids species, found that lactating females commenced foraging approximately 6 days after giving birth and on average made 7 foraging trips during the remainder of their 24-day lactation period.

So, we see that some phocids do NOT fast through the entire lactation period, and thus, logically, do not "consume a higher proportion of fat stores."

So, (C) conflicts with what can be inferred from the passage.

egmat · Answer

Question 1:

I can see why this question might be tricky - you're dealing with a lot of information about different seal families and their behaviors. Let me walk you through this step-by-step.

Here's the key insight you need to see:

When a question asks about what's true for  ALL  females of one species versus  ALL  females of another, you need to find a characteristic that has  no exceptions  mentioned in the passage.

Let's think through this systematically:

Step 1: What does the passage tell us applies to ALL otariids? 
The passage states that otariid lactation lasts "from 4 months to 3 years depending on the species." Every otariid mentioned follows this pattern.

Step 2: What applies to ALL phocids? 
Here's where it gets interesting. The passage says phocid lactation lasts "from 4 to 50 days depending on the species." Notice that even harbor seals, which break the fasting rule, still have only a 24-day lactation period.

Step 3: Eliminate the traps 
You might be tempted to pick foraging behavior differences, but here's the problem: harbor seals (which are phocids) actually  do  forage during lactation. So we can't say ALL phocids behave differently from otariids in terms of foraging.

Step 4: Find the universal difference 
The lactation periods are consistently different across both families:
-  ALL otariids:  4 months to 3 years
-  ALL phocids:  4 to 50 days

Notice how even the longest phocid lactation (50 days) is still shorter than the shortest otariid lactation (4 months = ~120 days).

The answer is (A) - have shorter lactation periods.

This biological difference holds true regardless of size, foraging behavior, or any other variable mentioned in the passage.

You can check out the  complete solution on Neuron by e-GMAT  to master the systematic framework for handling "ALL vs ALL" inference questions and learn how to quickly spot universal characteristics in complex passages. You can also explore other GMAT official questions with detailed solutions on Neuron for structured practice  here .

Until recently, zoologists believed that all species of phocids (true

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Reading Comprehension (RC) Questions

Until recently, zoologists believed that all species of phocids (true

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards