GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 20 Feb 2019, 07:38

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
  • Free GMAT Prep Hour

     February 20, 2019

     February 20, 2019

     08:00 PM EST

     09:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. Wednesday, February 20th at 8 PM EST
  • Online GMAT boot camp for FREE

     February 21, 2019

     February 21, 2019

     10:00 PM PST

     11:00 PM PST

    Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.

The goblin fern, which requires a thick layer of leaf litter on the fo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Director
Director
avatar
V
Joined: 30 Jan 2016
Posts: 928
Location: United States (MA)
Reviews Badge
The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 02 Sep 2017, 08:41
1
9
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

46% (02:36) correct 54% (02:32) wrong based on 290 sessions

HideShow timer Statistics

The goblin fern, which requires a thick layer of leaf litter on the forest floor, is disappearing from North American forests. In spots where it has recently vanished, the leaf litter is unusually thin and, unlike those places where this fern still thrives, is teeming with the European earthworm Lumbricus rubellus, which eats leaf litter. L. rubellus is thus probably responsible for the fern's disappearance.

Which one of the following is an assumption on which the argument depends?

(A) Wherever there is a thick layer of leaf litter in North American forests, goblin ferns can be found.
(B) None of the eartbworms that are native to North America eat leaf litter.
(C) Dead leaves from goblin ferns make up the greater part of the layer of leaf litter on the forest floors where the goblin fem has recently vanished.
(D) There are no spots in the forests of North America where both goblin ferns and earthworms of the species L. rubellus can be found.
(E) L. rubellus does not favor habitats where the leaf litter layer is considerably thinner than what is required by goblin ferns.

Source: LSAT

_________________

Non progredi est regredi

BSchool Forum Moderator
User avatar
V
Joined: 28 Mar 2017
Posts: 1219
Location: India
GMAT 1: 730 Q49 V41
GPA: 4
Re: The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 02 Sep 2017, 11:38
The goblin fern, which requires a thick layer of leaf litter on the forest floor, is disappearing from North American forests. In spots where it has recently vanished, the leaf litter is unusually thin and, unlike those places where this fern still thrives, is teeming with the European earthworm Lumbricus rubellus, which eats leaf litter. L. rubellus is thus probably responsible for the fern's disappearance.

Which one of the following is an assumption on which the argument depends?

(A) Wherever there is a thick layer of leaf litter in North American forests, goblin ferns can be found. -We already know this information from the passage. It can't be an assumption.
(B) None of the eartbworms that are native to North America eat leaf litter. -We are worried about the L. Rubellus earthworms. Out of scope.
(C) Dead leaves from goblin ferns make up the greater part of the layer of leaf litter on the forest floors where the goblin fem has recently vanished. -We are not worried about what constitute the various parts of leaf litter.
(D) There are no spots in the forests of North America where both goblin ferns and earthworms of the species L. rubellus can be found. -This will be a weakener.
(E) L. rubellus does not favor habitats where the leaf litter layer is considerably thinner than what is required by goblin ferns. -Correct. The L. Rubellus are found in thick covers of leaf litter that are essential for the growth of goblin fern.
_________________

Kudos if my post helps!

Long And A Fruitful Journey - V21 to V41; If I can, So Can You!!
Preparing for RC my way
RC Summary Activity - New Project to imporve RC Skills
Bloomberg's US Bschool Ranking

My study resources:
1. Useful Formulae, Concepts and Tricks-Quant | 2. e-GMAT's ALL SC Compilation | 3. LSAT RC compilation | 4. Actual LSAT CR collection by Broal | 5. QOTD RC (Carcass) | 6. Challange OG RC | 7. GMAT Prep Challenge RC

Intern
Intern
avatar
B
Joined: 26 Mar 2016
Posts: 16
Re: The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 02 Sep 2017, 11:48
OA -> E
Opposite is not true i.e L rubellus is not there because leaf layer is already thin.
BSchool Forum Moderator
User avatar
V
Joined: 28 Mar 2017
Posts: 1219
Location: India
GMAT 1: 730 Q49 V41
GPA: 4
Re: The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 02 Sep 2017, 11:59
1
shalabhg27 wrote:
OA -> E
Opposite is not true i.e L rubellus is not there because leaf layer is already thin.


Hi,

(E) L. rubellus does not favor habitats where the leaf litter layer is considerably thinner than what is required by goblin ferns.
Negation: "L. rubellus does not favor habitats where the leaf litter layer is NOT considerably thinner than what is required by goblin ferns".

This means that wherever the litter is thick (not considerably thin), they are not present. --> If they are not present in the thick layer of litter, then this weakens the argument, since it would mean that the thick layer of litter is being thinned out by some other being/natural force than the L. Rubellus.

OA is correct.
Hope that helps !!

P.S.: 1 piece of advice for you; instead of arguing that why the OA is incorrect, try to understand where did you go wrong. Since, this is an official LSAT question, it can't be wrong. It will help you to gain more knowledge.
_________________

Kudos if my post helps!

Long And A Fruitful Journey - V21 to V41; If I can, So Can You!!
Preparing for RC my way
RC Summary Activity - New Project to imporve RC Skills
Bloomberg's US Bschool Ranking

My study resources:
1. Useful Formulae, Concepts and Tricks-Quant | 2. e-GMAT's ALL SC Compilation | 3. LSAT RC compilation | 4. Actual LSAT CR collection by Broal | 5. QOTD RC (Carcass) | 6. Challange OG RC | 7. GMAT Prep Challenge RC

Director
Director
avatar
V
Joined: 30 Jan 2016
Posts: 928
Location: United States (MA)
Reviews Badge
Re: The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 14 Sep 2017, 23:27
Quote:
The trigger "˜thus’ helps us locate the conclusion here: L. rubellus is probably responsible for the fern’s disappearance. This is a causation conclusion: L is causing the fern to disappear. What is this conclusion based on? areas where fern recently vanished are teeming with L and have unusually thin leaf litter (and we’re told L eats leaf litter). It certainly seems reasonable to conclude that this is all L’s fault, but we know we must be very careful when making a causation conclusion. The premises offer us a correlation, but that’s never enough to prove causation. Perhaps an unknown factor is causing the fern to vanish, and L didn’t enter those areas until later? This could all just be one big misunderstanding! Let’s diagram the core:

Spots where fern recently vanished have unusually thin leaf litter, which is required by the fern + those spots are teeming with L, which eats leaf litter --> L is probably responsible for the fern’s disappearance

We’re looking for an answer choice that will make a coincidence less likely, and we’ll get rid of answer choices if negating them doesn’t kill the conclusion:

(A) doesn’t mention L so probably wrong; let’s negate it and see what happens: some North American forests with thick leaf litter don’t have any fern. No one ever said fern has to be in every spot that has thick leaf litter! So, even if the opposite of (A) is true, L could still be the reason for the fern’s disappearance. Get rid of this one.

(B) Let’s negate this one too: some earthworms other than L eat leaf litter. Even so, L could still be responsible for the fern’s disappearance. Get rid of this one.

(C) You’d probably expect to find evidence of dead fern in areas where the fern recently vanished. What if the fern’s dead leaves only made up the smaller part of the leaf litter (again, negation)? This changes nothing... L could still be responsible for the fern’s disappearance. Get rid of this one.

(D) Try negation again: what if you could find some spots in North American forests that have both L and fern? Even then, L could still be responsible for the fern’s disappearance _ perhaps the fern will disappear from those spots as well in the near future. Get rid of this one.

(E) Negation has worked really well for us in the first four answer choices, and at this point we’re hoping (E) is right, otherwise we’re in trouble. Let’s try negating this one as well: L favors habitats where the leaf litter layer is considerably thinner than what is required by the fern. Aha! This means that the fern vanished before L arrived! L couldn’t be responsible for the fern’s disappearance!

So (E) is correct.

_________________

Non progredi est regredi

Non-Human User
User avatar
Joined: 01 Oct 2013
Posts: 3637
Premium Member
Re: The goblin fern, which requires a thick layer of leaf litter on the fo  [#permalink]

Show Tags

New post 28 Jan 2019, 01:41
Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

-
April 2018: New Forum dedicated to Verbal Strategies, Guides, and Resources

GMAT Club Bot
Re: The goblin fern, which requires a thick layer of leaf litter on the fo   [#permalink] 28 Jan 2019, 01:41
Display posts from previous: Sort by

The goblin fern, which requires a thick layer of leaf litter on the fo

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.