IMO D
If you read this line "no two bacterial strains on Earth are different enough to have arisen on different planets" , D gives perfect criticism

What's OA

gmat009

IMO D
If you read this line "no two bacterial strains on Earth are different enough to have arisen on different planets" , D gives perfect criticism

What's OA


perfect!!!

one more for D..

OA??

IMO D

No brainer (D)

BE CAREFUL WITH GMATPREP, which contain 800 level OFFICIAL questions.
I agree oa is D but the problem is E choice
Why is E is wrong? negation of E make POSSIBILITY that all bacterial now is from Mar and weaken the argument. Only POSSIBILITY is good here.

EXPERT, PLEASE, HELP.

a similar question from Manhantan. In the following, Please, explain Why A is wrong?

A newly discovered painting on wooden panel by Michelangelo must have been completed after 1507 but before 1509. It cannot have been painted earlier than 1507 because one of its central figures carries a coin that was not minted until that year. It cannot have been painted after 1509 because it contains a pigment that Michelangelo is known to have abandoned when a cheaper alternative became available in that year.

Which of the following is an assumption on which the argument depends?
A)No stocks of the abandoned pigment existed after 1509.
B)Michelangelo did not work on the painting over the course of several years.
C)The coin depicted in the painting was known to general public in 1507.
D)The wooden panel on which the painting was executed cannot be tested accurately for age.
E)Michelangelo's painting style did not change between 1507 and 1509.

On both questions, I see that the negation of OA clearly and directly affect argument. But the attractive choices are good and satisfy the condition that there is a POSSIBILITY for bad case and this is weakening. A weakener dose not need to destroy argument. A weakener needs to increase the doubt.

EXPERT, please, help. GMATPREP is OG. Manhantan is a good source. we should be calm down to see the trick gmat want to test us inhere.

hey,
Sum1 pls explain the counter premise i m not able to discern the meaning. Furthermore, cudn't understand y E is wrong?

Thanx

beater wrote:It is theoretically possible that bacteria developed on Mars early in its history and that some were carried to Earth by a meteorite. However, strains of bacteria from different planets would probably have substantial differences in protein structure that would persist over time, and no two bacterial strains on Earth are different enough to have arisen on different planets. So, even if bacteria did arrive on Earth from Mars, they must have died out.
The argument is most vulnerable to which of the following criticisms?

(A) It fails to estabilish whether bacteria actually developed on Mars

(B) it fails to establish how likely it is that Martian bacteria were transported to Earth

(C) It fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.

(D) It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.

(E) It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.

I received a PM asking me to comment.
A FLAW is an error of reasoning that could WEAKEN the conclusion.

Premise: The strains of bacteria currently on Earth are NOT different enough to have arisen on DIFFERENT planets.
In other words, all of the strains of bacteria currently on Earth must have arisen on the SAME PLANET.
Conclusion: Since all of these strains arose on the same planet, they must all have arisen right here on Earth. If any bacteria did arrive from Mars, they must have died out.

Answer choice D points out the FLAW In this reasoning:
All bacteria now on Earth could have arisen from transported Martian bacteria.
It's possible that all of the strains of bacteria now on Earth have the SAME PROTEIN STRUCTURE because THEY ALL AROSE ON MARS, obliterating the conclusion that there are NO Martian bacteria currently on Earth.

The correct answer is D.

Answer choice E: There could have been strains of bacteria that originated on Earth and later died out.
So what?
Since all of the strains NOW on Earth have the SAME PROTEIN STRUCTURE, the conclusion that all of these strains arose on the SAME PLANET -- namely Earth -- is unaffected.
Eliminate E.