Biologists found that off the northeast coast of a certain country the

Question

Biologists found that off the northeast coast of a certain country the P-plankton population has recently dropped 10 percent. Additionally, fish species X, Y, and Z are beginning to show extraordinarily high death rates in the region. Since these species of fish are known to sometimes eat P-plankton, biologists believe the two phenomena are connected, but the exact nature of the connection is unknown. No other species in the ecosystem appear to be affected.

Which one of the following, if true, most helps to explain the biologists ' findings?

Which one of the following, if true, most helps to explain the biologists ' findings?

(A) Several major pharmaceutical companies in the region have been secretly dumping large amounts of waste into the ocean for many years.

(B) A new strain of bacteria is attacking P-plankton by destroying their cell walls and is attacking the respiratory systems of fish species X, Y, and Z.

(C) A powerful toxin in the water is killing off P-plankton by inhibiting their production of a chemical they use in reproduction.

(D) Fish species X, Y, and Z are all experiencing widespread starvation within the affected region, and the loss of P-plankton is driving their death rates up even higher.

(E) Global warming has changed the climatic conditions of the ocean all along the northeast coast of the country.

Source: LSAT

kushal11489 · Answer

I marked D. How to eliminate D ? It seems to give a missing link of how the population of X,Y,and Z is decreasing after the sudden decrease in population of P-plankton

sandy217 · Answer

They "sometimes eat", not always. Experiencing widespread starvation because of that, becomes an overstatement.

chetan2u · Answer

Hi..

Para :-
There is a reduction in numbers of P and also in Numbers of fish species X,Y and Z, who sometimes feed on P. Biologists believe to be interlinked.

The closest answers are B and D.

You are likely to fall for D, if you think INTERCONNECTED means loss of P leads to loss of fishes.
 Here interconnected can easily mean some COMMON event resulting in loss of both.
 
So why it should not be D.
 D clearly says there is already a huge loss occuring and the loss of P further increases.
So the two events are not connected as the loss is occurring even in absence of loss of P.
The events are - heavy loss of fishes, then loss of P, further increase in already heavy loss.
 
B Clearly states a THIRD reason leading to both the events
 Events :- a new strain of bacteria, loss of P and loss of fishes .

So B

broall · Answer

(A) Several major pharmaceutical companies in the region have been secretly dumping large amounts of waste into the ocean for many years. 
 This choice can't explain the biologists' findings. Also, this choice seems to attack the finding that "No other species in the ecosystem appear to be affected."

(B) A new strain of bacteria is attacking P-plankton by destroying their cell walls and is attacking the respiratory systems of fish species X, Y, and Z.
 Correct. This choice explains the findings well by giving the reason that the population of both P-plankton and fish species has declined.

(C) A powerful toxin in the water is killing off P-plankton by inhibiting their production of a chemical they use in reproduction.
 This choice just tries to explain why P-plankton population has declined. This choice, however, fails to explain why fish species populations also declined.

(D) Fish species X, Y, and Z are all experiencing widespread starvation within the affected region, and the loss of P-plankton is driving their death rates up even higher.
 This choice contradicts the argument above. This choice tries to establish a connection between the two phenomena.

(E) Global warming has changed the climatic conditions of the ocean all along the northeast coast of the country.
 Global warming could effect any species, not just those fish species and P-plankton. This choice fails to explain the findings above.

Oli0139 · Answer

The passage says "recently..." for P and "beginning to..." for X,Y,Z. How do you infer that the loss of fish occurred before that of P?

kartickdey · Answer

bb   Bunuel   Sajjad1994   KarishmaB 
It is written in the passage that fishes suffered extraordinary high loss whereas plankton is facing only 10% decline. In option B, that I think is not somehow reflected. But in option D it is stated that the loss of P-plankton is driving their death rates up even higher. It appears that the extraordinary high loss is explained to some extent by that "up even higher" phrase. Please explain where my thought is wrong....

guddo · Answer

Biologists found that off the northeast coast of a certain country the P-plankton population has recently dropped 10 percent. Additionally, fish species X, Y, and Z are beginning to show extraordinarily high death rates in the region. Since these species of fish are known to sometimes eat P-plankton, biologists believe the two phenomena are connected, but the exact nature of the connection is unknown. No other species in the ecosystem appear to be affected.

Which one of the following, if true, most helps to explain the biologists ' findings?

Which one of the following, if true, most helps to explain the biologists ' findings?

The biologists found a 10% drop in P-plankton and high death rates in three fish species that sometimes eat the plankton, with no other species affected. They suspect a link but don't know the exact connection.

(A) Several major pharmaceutical companies in the region have been secretly dumping large amounts of waste into the ocean for many years.

Industrial waste dumping could harm marine life but would likely affect many species, not just these four, contradicting that no others appear affected.

(B) A new strain of bacteria is attacking P-plankton by destroying their cell walls and is attacking the respiratory systems of fish species X, Y, and Z.

A new bacteria attacks both P-plankton’s cell walls and the respiratory systems of fish X, Y, and Z. This explains both phenomena with one specific cause that spares other species, aligning perfectly with the findings.

(C) A powerful toxin in the water is killing off P-plankton by inhibiting their production of a chemical they use in reproduction.

A toxin killing P-plankton only explains the plankton decline, not the fish deaths. Fish might eat less plankton, but that doesn’t directly cause high death rates, nor does it explain why only these fish are affected.

(D) Fish species X, Y, and Z are all experiencing widespread starvation within the affected region, and the loss of P-plankton is driving their death rates up even higher.

Starvation linked to plankton loss describes a consequence but doesn’t explain why the plankton dropped initially. It also doesn’t clarify why only these three fish species are starving if they only sometimes eat plankton.

(E) Global warming has changed the climatic conditions of the ocean all along the northeast coast of the country.

Global warming is too broad and would likely impact many species, not just P-plankton and these three fish, again contradicting that no other species are affected.

Thus,  option (B)  provides the most precise and complete explanation.

guddo · Answer

Option D does not explain why the plankton fell by 10%. It also does not say what started the fish starving. It only says the plankton loss makes an existing problem worse. So it leaves both facts unexplained.

Option B explains both. One bacteria causes the plankton decline and also directly kills the fish. The bacteria can affect each group differently, which is why the fish die more than the plankton decline. This fits all the facts.

So B is correct.

KarishmaB · Answer

Population dropping by 10% and extraordinarily high death rates convey similar information. For any stable species, birth and death rates move very slowly. If normal death rate is 5% of population in a year, a death rate of 8% would be extraordinarily high. Population dropping by 10% is surprising too. Hence all that the argument is saying is that P Plankton and X, Y, Z are the ones affected. Other populations are not.

Option (B) explains the presence of a bacteria impacting P, X, Y and Z. So that is why these 4 are getting impacted.

For (D), we do not know why other fish are not facing starvation. It doesn't explain why only X, Y and Z are affected and it doesn't explain why pop of P is going down.

Biologists found that off the northeast coast of a certain country the

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