V06-10

Question

In a polluted area around the Great Lakes, scientists studying bird populations have observed a drop in the number of both herring gulls and terns. Both bird species prey on the same type of fish, whose numbers are also being negatively affected by pollution. However, the tern population has seen a much sharper decrease than the herring gull population. Scientists have concluded that the herring gulls have a higher survival rate because they are able to find alternative sources of food, including garbage dumps along the shoreline.
 
Which of the following, if true, would provide the best piece of evidence in support of the researchers’ conclusion?

A. A survey shows that bird populations in areas around the Great Lakes have shown similar decreases.
B. A related study finds that fish populations in the Great Lakes are affected as much by other predators as by pollution.
C. Maps of the area reveal that the largest garbage dump in the area is located 3 miles inland from the lake.
D. Blood tests performed on the gulls reveal high levels of the types of fatty acids generally found only in human food.
E. Analysis of water in the area where the birds nest reveals that toxin levels are actually slightly below fish tolerance levels.

Bunuel · Answer

Official Solution:

In a polluted area around the Great Lakes, scientists studying bird populations have observed a drop in the number of both herring gulls and terns. Both bird species prey on the same type of fish, whose numbers are also being negatively affected by pollution. However, the tern population has seen a much sharper decrease than the herring gull population. Scientists have concluded that the herring gulls have a higher survival rate because they are able to find alternative sources of food, including garbage dumps along the shoreline.
 
Which of the following, if true, would provide the best piece of evidence in support of the researchers’ conclusion?

A. A survey shows that bird populations in areas around the Great Lakes have shown similar decreases.
B. A related study finds that fish populations in the Great Lakes are affected as much by other predators as by pollution.
C. Maps of the area reveal that the largest garbage dump in the area is located 3 miles inland from the lake.
D. Blood tests performed on the gulls reveal high levels of the types of fatty acids generally found only in human food.
E. Analysis of water in the area where the birds nest reveals that toxin levels are actually slightly below fish tolerance levels.

Situation : Herring gull and tern populations have both decreased in a polluted area, but herring gulls show a higher survival rate.
 
 Reasoning :  Which of the following is the best evidence supporting the researchers’ conclusion?  The researchers claim that the herring gulls have a higher survival rate because they, unlike the terns, are able find a food source other than the fish they generally eat. The researchers claim this alternative food source is the garbage in dumps along the shoreline. Any evidence that the herring gulls have been eating garbage will support the researchers’ conclusion.
 
A. This option does not explain why tern populations have decreased more dramatically than herring gull populations.
 
B. Additional information about the fish does not give researchers information about the differences in the tern and herring gull populations.
 
C. The distance of the garbage dumps from the shoreline is not directly relevant to the researchers’ conclusion.
 
 D. CORRECT.  Evidence of fatty acids from human food would provide direct confirmation that the herring gulls had a higher survival rate because they were using the garbage dumps as an alternative food source.
 
E. This option may provide information about fish species, but it does not directly address the researchers’ questions about herring gulls.

Answer: D

dominicraj · Answer

Hi,

Option D: Blood tests performed on the gulls reveal high levels of the types of fatty acids generally found only in human food. This argument gives way for several flaws
for Eg. 
1) The fatty acids are "generally" found in human food. Hence there is a possibility that they can be inherently found in birds as well as in our case.
2) "Alternate sources of food,including dumping grounds" need not necessarily mean "human food" as claimed in option D

Whereas option C:
Maps of the area reveal that the largest garbage dump in the area is located 3 miles inland from the lake
 1) This ensures that the garbage dump is in the vicinity as claimed in the passage.
2) Does not say about the alternate sources of food and talks just about the dumping ground hence not restricting itself to "just human food" as option D does.

Kindly explain.

Regards,
Dom.

Devesh29 · Answer

Can someone please explain the answer and why option c is incorrect?

Atbr1602 · Answer

I have the same inquiries as "dominicraj". Can anyone please help?

gvikramjee · Answer

Option C: Maps of the area reveal that the largest garbage dump in the area is located 3 miles inland from the lake.
This says there is a garbage dump nearby but that does not imply that gulls are eating the food from these dumps.

Option D: Blood tests performed on the gulls reveal high levels of the types of fatty acids generally found only in human food.
this option makes is more likely that if there are high levels of fatty acids from food; then the gulls must have eaten human food from somewhere.

Now look at the claim in the question
Scientists have concluded that the herring gulls have a higher survival rate because they are able to find alternative sources of food, including garbage dumps along the shoreline.

The scientists claim that gulls are finding alternate sources of food, which include garbage dumps but dumps are not the only source.

PreiteeRanjan · Answer

Any qn related to strengthen kind can be solved using the mechanism i am going to write here.the only problem is i dont deal with shortcuts.

Always find that why the author concluded so, followed by some fatcs and without chowing any logical connection.see this is the basic trick to deal.
 now someone may tell that the process is time consuming,however answers to such typical 700+ qns can be found with proper confidence using this trick.it may take time,but it ll reduce drastically.once you know watever you r marking is correct,the ability to solve next qn ll be more. 
now come to the qn,what the author syas is ctegory x survival is more than category y,then the author shows some fact and jumped to the conclusion directly that is its something alternative source, garbage, which is causing so.now you need to ask urself how can the author directly conclude so.this much you prethink.

how to find correct answer choice.

basic rule is 
the correct answer choice always shows the proper logical gap including cause and effect ,a new information, and not a single dependence such as only cause based emphasis or only effect based emphasis.

now option c:if you try to say area is full of garbage and bird x is eating them, then the second part than the bird actually eats those garbage is not mentioned in the option choice and you basically assumed the same, which is the only condition of reasoning. never assume any thing of ur own.

now option d:now somebody may say where it is written in option d that human food is take by bird x, however the author presents garbage as an example, the main content is alternate food source, which logical gap is filled by option d.

Nutakki45092001 · Answer

I like the solution - it’s helpful.

V06-10

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