Last visit was: 23 Jul 2024, 13:51 It is currently 23 Jul 2024, 13:51
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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
VP
VP
Joined: 29 Aug 2012
Status:Chasing my MBB Dream!
Posts: 1055
Own Kudos [?]: 6337 [21]
Given Kudos: 330
Location: United States (DC)
WE:General Management (Aerospace and Defense)
Send PM
Most Helpful Reply
Director
Director
Joined: 05 Feb 2018
Posts: 755
Own Kudos [?]: 2308 [5]
Given Kudos: 139
Location: India
Concentration: Finance
GPA: 2.77
WE:General Management (Other)
Send PM
General Discussion
Manager
Manager
Joined: 18 Mar 2015
Posts: 80
Own Kudos [?]: 12 [0]
Given Kudos: 116
Location: India
Schools: ISB '19
GMAT 1: 600 Q47 V26
GPA: 3.59
Send PM
Intern
Intern
Joined: 13 Sep 2016
Posts: 10
Own Kudos [?]: 1 [0]
Given Kudos: 5
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
What are the answers of the RC... I found option C for question 1, option D for question 2 and option D again for question 3

Sent from my Redmi Note 3 using GMAT Club Forum mobile app
Manager
Manager
Joined: 18 Mar 2015
Posts: 80
Own Kudos [?]: 12 [0]
Given Kudos: 116
Location: India
Schools: ISB '19
GMAT 1: 600 Q47 V26
GPA: 3.59
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
manoj1115 wrote:
What are the answers of the RC... I found option C for question 1, option D for question 2 and option D again for question 3

Sent from my Redmi Note 3 using GMAT Club Forum mobile app

answers are 1.D 2.D 3.D. amswer is given with the question
Intern
Intern
Joined: 24 Jun 2017
Posts: 9
Own Kudos [?]: 8 [1]
Given Kudos: 22
GMAT 1: 750 Q49 V44
GPA: 3.1
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
1
Kudos
Hmmm.

I agree with Qs 1 and 3. I'm having trouble justifying the OA to question 2? Where in the passage does it discuss marine strata?
Intern
Intern
Joined: 26 Mar 2017
Posts: 21
Own Kudos [?]: 10 [1]
Given Kudos: 32
GMAT 1: 720 Q50 V38
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
1
Kudos
Gnpth wrote:
In 1979, a team of scientists from Berkeley working near Gubbio, Italy, discovered a layer of clay that revolutionized theories concerning the disappearance of the dinosaur, which had centred on the assumed gradual climatic change. Beneath the two-centimetre-thick layer lay limestone containing fossil organisms from the late Cretaceous, while above it was limestone with early Cenozoic fossils.

Positionally, then, the Berkeley group could place the clay in a period roughly contemporaneous with the disappearance of the dinosaur approximately 63 million years ago. They found that the clay stratum contained an iridium level thirty times greater than that of clays in adjacent strata. As iridium is distributed fairly evenly over time through micrometeoritic impact, the researchers knew that the anomalous matter in the clay must have originated extra-terrestrially; the high iridium level, moreover, indicated a sudden deposition in an exceptional, catastrophic event.

Scientists are sharply divided on the possible causes of so cataclysmic an event. The possibility that the deposition occurred as an aftereffect of a supernova has been discounted: radioactive isotope Pu-244 was absent from the clay, and neither Ir-191 nor Ir-193 were present in significant proportions.

Those who maintain that the material came from within the solar system contend that the earth must have collided during the late Cretaceous with an astral body large enough to have distributed the iridium-rich material over the globe. An asteroid of the required mass would have been approximately ten kilometres in diameter; a comet would have to have been twice as large, since comets are largely composed of ice water.

Trying to fathom the scale of such an event as this is mind boggling. It is true that from space, an object 10-20 miles across colliding with earth would be akin to something smaller than a grain of sand landing on a basketball, it is also the case that an object twenty miles across that landed on earth would be nearly twice as tall as Mt. Everest (the tallest mountain on Earth) and further across than the length of Manhattan. Furthermore, when the body came crashing to Earth it would have been ablaze in an inferno caused by the friction of entry into our atmosphere. To the argument that there is no geological evidence of the impact of such massive objects, Richard Grieve has replied that the clay layer could have resettled after the impact in the form of fallout. Frank Kyte of UCLA asserts that a comet, if disrupted by the earth‘s gravitational field, would have exposed the surface to a deluge of debris that would not have created major craters. Alternatively, the Berkeley group suggests that an asteroid may have landed in the sea; such a collision would have produced tidal waves eight kilometres high, swamping large areas of the earth.

Whatever the type of body and mode of impact, Walter Alvarez of the Berkeley team argues that the primary effect of the catastrophe was to disrupt the planetary ecology through the suspension of vast clouds of matter in the stratosphere. The effects of the initial impact would have been greatly multiplied, Alvarez argues, as photosynthesis was impeded by the blockage of sunlight; there would then have been a massive disruption at the base of the dinosaur‘s food chain.

The passage discusses a new discovery that may change the way scientists think about one aspect of dinosaurs. It can be inferred that the discovery described in the passage may ―revolutionize‖ (line 4) which aspect of current theories about dinosaurs?
A. The geographical extent of the presumed habitation of the dinosaur
B. The approximate date at which dinosaurs are thought to have become extinct
C. The assumption that dinosaurs became extinct because of a change in their natural environment
D. The rate at which the extinction of the dinosaur is thought to have occurred
E. The notion that dinosaurs became extinct because of the onset of an ice age.


According to the passage, the Berkeley group used which of the following to support their hypothesis on the disappearance of the dinosaur?
I. A comparison of the fossil records of various marine strata
II. A comparison of different clay strata near Gubbio, Italy
III. A comparison of marine strata in several locations
A. I only
B. III only
C. I and II
D. II and III
E. I, II and III


According to the information presented by the author throughout the passage, scientists used the analysis of the isotopes present in the clay to:
A. estimate the age of the stratum more exactly.
B. determine the extent of meteoritic impact upon the earth.
C. derive a hypothesis concerning the effect of the impact of an extraplanetary body on the earth‘s ecology.
D. eliminate a possible theory concerning the enriched clay‘s formation.
E. determine whether dinosaurs were allergic to these


Gnpth,
Please check the answer choices in Q2. I cannot find anything in the passage that talks about marine data.
Intern
Intern
Joined: 27 Dec 2015
Posts: 20
Own Kudos [?]: 6 [1]
Given Kudos: 1190
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
1
Kudos
Where as mentioned in Q2 answer has the author mentioned that the scientists compared the marine strata and how for Q3 can we deduce that D is correct answer?
Director
Director
Joined: 05 Feb 2018
Posts: 755
Own Kudos [?]: 2308 [0]
Given Kudos: 139
Location: India
Concentration: Finance
GPA: 2.77
WE:General Management (Other)
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]

Topic and Scope

- The iridium layer‘s impact on theories of dinosaur extinction

Mapping the Passage


¶s 1 and 2 describe the Berkeley group's discovery of the iridium layer and its significance to dinosaur extinction.
¶3 discusses conflicting theories for the cause of iridium deposition.
¶s4 and 5 elaborate on various theories that an asteroid or comet was responsible for the iridium layer.
¶6 presents Alvarez‘s mechanism for extinction: debris from impact blocked sunlight, impeded photosynthesis, and harmed the dinosaurs‘ food chain.
Intern
Intern
Joined: 18 Sep 2017
Posts: 11
Own Kudos [?]: 4 [0]
Given Kudos: 29
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
can anyone explain this passage.i am not getting its oa to be correct.ques 1 and 2nd is hard to solve
GRE Forum Moderator
Joined: 02 Nov 2016
Posts: 14064
Own Kudos [?]: 36824 [0]
Given Kudos: 5834
GPA: 3.62
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
Expert Reply
Hi

Question number 2 is off the passage in my point of view, Official Explanation didn't support the question to be a perfect one, Three options in the question are flawed. I have selected C as the answer based on my guess and i was not confident about that even. generis your views on question number 2 may prove helpful.

Thanks

ssaamm wrote:
can anyone explain this passage.i am not getting its oa to be correct.ques 1 and 2nd is hard to solve
Senior SC Moderator
Joined: 22 May 2016
Posts: 5325
Own Kudos [?]: 35778 [3]
Given Kudos: 9464
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
3
Kudos
Expert Reply
SajjadAhmad wrote:
Hi

Question number 2 is off the passage in my point of view, Official Explanation didn't support the question to be a perfect one, Three options in the question are flawed. I have selected C as the answer based on my guess and i was not confident about that even. generis your views on question number 2 may prove helpful.

Thanks

ssaamm wrote:
can anyone explain this passage.i am not getting its oa to be correct.ques 1 and 2nd is hard to solve



Quote:
Question 2
According to the passage, the Berkeley group used which of the following to support their hypothesis on the disappearance of the dinosaur?

I. A comparison of the fossil records of various marine strata
II. A comparison of different clay strata near Gubbio, Italy
III. A comparison of marine strata in several locations
A. I only
B. III only
C. I and II
D. II and III
E. I, II and III

SajjadAhmad , either this author went off the deep end or the passage was changed but the questions were not.

Question 2 is flawed. I would delete it.

Only option II has textual support.
No textual support exists for I or III.

• support for II

The Berkeley people DID use
II. A comparison of different clay strata near Gubbio, Italy
to support their hypothesis about dinosaur extinction.

The Berkeley group's hypotheses about the disappearance of the dinosaur, roughly, is
(1) conclusion: the dinosaur disappeared quickly, not gradually

(2) that quick disappearance was caused by a catastrophic event: a large extra-terrestrial body hit somewhere on earth (probably the sea), sending vast clouds of matter into the stratosphere that blocked out the sun

(3) No sun = no photosynthesis = no plants. Plant-eating dinosaurs perish. Meat-eating dinosaurs that eat plant-eating dinosaurs perish.

What did the Berkeley group use to support its hypothesis?

1. The date of the clay (coincides with time period during which dinosaurs perished)

Paragraph 1: Two layers of limestone sandwiched a layer of clay.
Berkeley scientists knew the dates of the eras during which the limestone formed.
The clay lay in between the end of one era and the beginning of the other.
The "between two eras" allowed scientists to
"place the clay in a period roughly contemporaneous with the disappearance of the dinosaur approximately 63 million years ago."

2. Unearthly levels of iridium in that layer of clay compared to iridium in other layers of clay indicated that the iridium was deposited by an extra-terrestrial body that caused a catastrophic event.
Paragraph 2: (They found that the clay stratum contained an iridium level thirty times greater than that of clays in adjacent strata. )
During the same time period that dinosaurs became extinct, a celestial body hit the earth.

3. Effect? Matter flooded the stratosphere, blocked out the sun, and prevented photosynthesis.
Plants, plant-eating dinosaurs, and meat-eating dinosaurs perished quickly. (Last paragraph.)

Option II has support.

Both I and III depend on the presence of marine strata.
If Option III has no support, then Option I has none, either.
Start with Option III

Can we find any hint that the Berkeley people examined marine strata?
-- Marine strata = Ocean or sea layers. (Marine refers to seas.)

• Option III (and I): are not supported by the passage.

The passage does not mention marine strata (sea or ocean layers).

One reference to the sea exists: The earth may have been flooded by sea water.

I wondered whether I could reason this way:

1) Berkeley people believe that object MAY have landed in the sea, a landing that caused large areas of flooding
-- (Paragraph 5: Alternatively, the Berkeley group suggests that an asteroid may have landed in the sea; such a collision would have produced tidal waves eight kilometres high, swamping large areas of the earth.)

2) Two different limestone layers are mentioned.
(Paragraph 1 - The limestone layer beneath the clay contain[ed] fossil organisms from the late Cretaceous, while above [the layer of clay] was limestone with early Cenozoic fossils.)

3) Maybe the text would connect limestone to water, the sea, or flooding? No.
Clay is not connected to sea water, either.

No mention of marine strata.
No connection of mentioned limestone and clay strata to sea water.
No mention of "various places."
The Berkeley people did not use anything from Options I or III to support their hypothesis.

Logically, it is not possible to jump from "a possible impact in ocean that created tidal waves, swampinglarge areas of earth"
to "
a comparison of marine strata in several locations."

GAh. Bad questions are the hardest to explain. This question is so awful that I suspect an editing mistake.

Your instincts are correct.
Hope that helps.
avatar
Intern
Intern
Joined: 08 Apr 2022
Posts: 1
Own Kudos [?]: 0 [0]
Given Kudos: 1
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
I didnt understand qn 1...How does gradual climatic change translate to rate of extinction?
User avatar
Non-Human User
Joined: 01 Oct 2013
Posts: 17526
Own Kudos [?]: 869 [0]
Given Kudos: 0
Send PM
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
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.
GMAT Club Bot
Re: In 1979, a team of scientists from Berkeley working near Gubbio, Italy [#permalink]
Moderators:
GMAT Club Verbal Expert
6991 posts
GMAT Club Verbal Expert
236 posts
GRE Forum Moderator
14064 posts