Researchers traditionally have attempted to track animals by tagging

Question

Researchers traditionally have attempted to track animals by tagging them. Seeking an alternative tracking method, Brian W. Bowen, an evolutionary geneticist, turned to four green turtle breeding sites in the Atlantic and the Caribbean. He and his co-workers reported that turtles from the four breeding sites tended to have slightly different genetic markings.

Bowen analyzed mitochondrial DNA from eggs and hatchlings. The  existence of variations in DNA among geographically distinct  groups has helped scientists evaluate the different theories of the mating habits of the green turtle. Their findings, Bowen asserts, lend credence to the “natal homing” theory. This theory holds that while reptiles born in different regions may share common feeding grounds away from home, the animals part company at breeding time, each swimming hundreds or thousands of miles to breed and nest at its own birthplace.

Bowen and his co-workers, however, offer several caveats to the interpretation of their findings. They note that turtles from two of the nesting sites—Florida’s Hutchinson Island and Costa Rica’s Tortuguero sanctuary—had indistinguishable mitochondrial DNA sequences. This finding indicates that either some social mixing occurred between these two groups or that the DNA test was not sensitive enough to detect extremely subtle differences in DNA. In addition, they report that one of eight study turtles from Aves Island, off Venezuela, showed the same genetic pattern as the Tortuguero and Hutchinson turtles in their sample. Nonetheless, Bowen’s study appears to have bolstered the idea that most populations of green turtles are genetically distinct, and that the turtles return to their birthplaces at nesting time.   1 
 Q1. It can be inferred from the passage that the turtles from the Aves Island study

A. had, with the exception of one, genetic patterns distinct from those in the Tortuguero study
B. have shown that using DNA to track turtles is a flawed technique
C. all exhibited genetic patterns similar to those of the Hutchinson and Tortuguero study turtles
D. are part of an endangered species
E. had DNA that differs from those turtles that are from Venezuela

2 
 Q2. The primary purpose of this passage is to

A. disprove a previously existing theory
B. present a new idea along with some data
C. establish the infallibility of a new concept
D. confirm the validity of a novel hypothesis
E. track the development of a particular species

3 
 Q3. The information provided in the passage about Bowen's research can be used to answer which of the following questions?

A. Does social mixing occur between turtles from Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary?
B. Is there extensive interbreeding among green turtles from different areas?
C. To what extent can DNA testing be used to detect genetic differences?
D. Does tagging wild animals with metal disks or wires alter their mating habits?
E. By what mechanism do green turtles find their way back to their birthplace when they are ready to breed?

4 
 4. According to the passage, the discovery of the “existence of variations in DNA among geographically distinct" ( Highlighted ) turtle groups has

A. helped Bowen to become one of the field's leading experts
B. discredited previous notions of turtle breeding
C. confirmed the existence of a single original species of turtle
D. given some validity to the "natal homing" theory
E. explained similarities between turtles with subtle DNA differences

5 
 5. According to the passage, Bowen developed his natural markings tracking method in order to

A. find a way to track turtles without interfering in their natural routines
B. discover an alternative to tagging animals
C. overcome difficulties in tagging turtles with disks or wires
D. show that the possibilities of DNA technology are virtually limitless
E. lend credence to the "natal homing" theory

6 
 6. Which of the following would most strengthen the “natal homing" theory concerning the genetic differences among green turtles?

A. New studies indicate that green turtles can interbreed and their offspring still retain genetic distinctions.
B. The population of green turtles at Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary has declined in recent years.
C. Bowen was recently asked to do further research on genetic differences among green turtles.
D. Recent tests found that there were subtle differences between the mitochondrial UNA sequences found in turtles from Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary.
E. Research done on DNA testing has shown that DNA is not always a reliable measure of genetic differences.

7 
 7. According to the passage, which of the following supports the contention that green turtles rarely interbreed?

A. Some turtles from Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary had indistinguishable mitochondrial DNA sequences.
B. One of eight turtles studied from Aves Island, Venezuela shared a genetic pattern characteristic of turtles from a different breeding ground.
C. When analyzing the DNA of turtles, scientists found differences in the genetic makeup of turtles from various areas.
D. Bowen's team found a discrete mitochondrial pattern in each turtle they studied.
E. Turtles from each nesting ground share common feeding grounds that may be thousands of miles apart.

Sreyoshi007 · Accepted Answer

Q1. It can be inferred from the passage that the turtles from the Aves Island study

A. had, with the exception of one, genetic patterns distinct from those in the Tortuguero study

Correct as mentioned directly in the passage.

B. have shown that using DNA to track turtles is a flawed technique

The passage doesn't say that. Agreed that there are multiple interpretations of the technique by Bowen and his co-workers as mentioned in the first line of last para. But the last line of the same para supports the study. Eliminate B

C. all exhibited genetic patterns similar to those of the Hutchinson and Tortuguero study turtles

Nope. only One out of the eight does.

D. are part of an endangered species

Nowhere mentioned. Eliminate

E. had DNA that differs from those turtles that are from Venezuela

Nowhere mentioned. Eliminate

Q2. The primary purpose of this passage is to

A. disprove a previously existing theory

Nope. It doesn't disprove the existing thoery. As first line of the passage suggests, they are only looking for alternate theories.

B. present a new idea along with some data

Bingo!! That's what's discussed throughout the passage

C. establish the infallibility of a new concept

Wrong. The new concept also does have some loopholes which are discussed in the last para. There are multiple interpretations of the technique by Bowen and his co-workers as mentioned in the first line of last para

D. confirm the validity of a novel hypothesis

They don't confirm it's validity. They only mention in the last line that the study bolsters an idea.

E. track the development of a particular species

The primary purpose is to look for some new idea to track animals. For that purpose they track a particular species. Classic trap choice

Q3. The information provided in the passage about Bowen's research can be used to answer which of the following questions?

A. Does social mixing occur between turtles from Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary?

It doesn't answer that, Passage itself mentions that there are multiple interpretations

B. Is there extensive interbreeding among green turtles from different areas?

Correct. As the passage mentions "Bowen’s study appears to have bolstered the idea that most populations of green turtles are genetically distinct, and that the turtles return to their birthplaces at nesting time.". There may be interbreeding among some species as mentioned in the last para. But that is only speculated. Their findings, Bowen asserts, lend credence to the “natal homing” theory. So there is no way extensive interbreeding will happen. Because if it does then why would turtles swim thousands of miles to their homelands.

C. To what extent can DNA testing be used to detect genetic differences?
Doesn't answer

D. Does tagging wild animals with metal disks or wires alter their mating habits?
Nowhere mentioned

E. By what mechanism do green turtles find their way back to their birthplace when they are ready to breed?
Nowhere mentioned

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Prateek176 · Answer

Q1. It can be inferred from the passage that the turtles from the Aves Island study

A. had, with the exception of one, genetic patterns distinct from those in the Tortuguero study

Correct as mentioned directly in the passage.

B. have shown that using DNA to track turtles is a flawed technique

The passage doesn't say that. Agreed that there are multiple interpretations of the technique by Bowen and his co-workers as mentioned in the first line of last para. But the last line of the same para supports the study. Eliminate B

C. all exhibited genetic patterns similar to those of the Hutchinson and Tortuguero study turtles

Nope. only One out of the eight does.

D. are part of an endangered species

Nowhere mentioned. Eliminate

E. had DNA that differs from those turtles that are from Venezuela

Nowhere mentioned. Eliminate

Q2. The primary purpose of this passage is to

A. disprove a previously existing theory

Nope. It doesn't disprove the existing thoery. As first line of the passage suggests, they are only looking for alternate theories.

B. present a new idea along with some data

Bingo!! That's what's discussed throughout the passage

C. establish the infallibility of a new concept

Wrong. The new concept also does have some loopholes which are discussed in the last para. There are multiple interpretations of the technique by Bowen and his co-workers as mentioned in the first line of last para

D. confirm the validity of a novel hypothesis

They don't confirm it's validity. They only mention in the last line that the study bolsters an idea.

E. track the development of a particular species

The primary purpose is to look for some new idea to track animals. For that purpose they track a particular species. Classic trap choice

Q3. The information provided in the passage about Bowen's research can be used to answer which of the following questions?

A. Does social mixing occur between turtles from Florida's Hutchinson Island and Costa Rica's Tortuguero sanctuary?

It doesn't answer that, Passage itself mentions that there are multiple interpretations

B. Is there extensive interbreeding among green turtles from different areas?

Correct. As the passage mentions "Bowen’s study appears to have bolstered the idea that most populations of green turtles are genetically distinct, and that the turtles return to their birthplaces at nesting time.". There may be interbreeding among some species as mentioned in the last para. But that is only speculated. Their findings, Bowen asserts, lend credence to the “natal homing” theory. So there is no way extensive interbreeding will happen. Because if it does then why would turtles swim thousands of miles to their homelands.

C. To what extent can DNA testing be used to detect genetic differences?
Doesn't answer

D. Does tagging wild animals with metal disks or wires alter their mating habits?
Nowhere mentioned

E. By what mechanism do green turtles find their way back to their birthplace when they are ready to breed?
Nowhere mentioned

Kudos if you like the post

prashant6923 · Answer

Q1:A
In addition, they report that one of eight study turtles from Aves Island, off Venezuela, showed the same genetic pattern as the Tortuguero

Above gives the answer of the question.

Q2:B Present a new idea along with some data

Para 2 tells about Natal homing theory and says the "animals part company at breeding time, each swimming hundreds or thousands of miles to breed and nest at its own birthplace. "
Para 3 Accepts the things said in para 2 but with some caveats.Those caveats include some data.

Nikhil · Answer

tejyr  Please read the following excerpt.

This finding indicates either "social mixing occurred" or "some other event" So, there are two possibilities. Option A cannot be answered as we don't have a concrete info on the occurrence of social mixing. The passage states that either social mixing happened or some other event happened. Hence option A is incorrect.

option B can be answered by the passage using the following lines.

1. Brian W. Bowen, an evolutionary geneticist, turned to four green turtle breeding sites in the Atlantic and the Caribbean.
2. The existence of variations in DNA among geographically distinct groups has helped scientists evaluate the different theories of the mating habits
3. reptiles born in different regions may share common feeding grounds away from home
4. they report that one of eight study turtles from Aves Island, off Venezuela, showed the same genetic pattern as the Tortuguero and Hutchinson turtles
5. Bowen’s study appears to have bolstered the idea that most populations of green turtles are genetically distinct

dabaobao · Answer

Took 6:26 min in total including 3 min to read the passage!

Passage Map: 
1) Alternate Method
2) Analysis supports "natal homing” theory 
3) Caveats of new alternate method; Conclusion

Adambhau · Answer

Can you or anyone please give an explanation of question 7. I was confused between B and C. Then I went for B. Thanks!

bM22 · Answer

Hi  Adambhau ,

7. According to the passage, which of the following supports the contention that green turtles rarely interbreed?

For this Question we are looking for an option that supports that argument that green turtles rarely interbreed. Let's look at the options B and C.

This is the second part of Bowen's theory, that bolstered the idea that most populations of green turtles are genetically distinct, and that turtles return to their birthplaces at nesting time.

Now this option is correct statement wise, as its present in the passage, but is it relevant to the Question asked? No, we need an answer that supports the above contention.

Correct, as this option is a paraphrase of the information present in the second para, which discusses one side of Bowen's research that scientists found differences in the genetic makeup of turtles from various areas.

Thus answer is C is the correct answer.

Hope This Helps.
Thanks.

Adambhau · Answer

Hi  Adambhau ,

7. According to the passage, which of the following supports the contention that green turtles rarely interbreed?

For this Question we are looking for an option that supports that argument that green turtles rarely interbreed. Let's look at the options B and C.

This is the second part of Bowen's theory, that bolstered the idea that most populations of green turtles are genetically distinct, and that turtles return to their birthplaces at nesting time.

Now this option is correct statement wise, as its present in the passage, but is it relevant to the Question asked? No, we need an answer that supports the above contention.

Correct, as this option is a paraphrase of the information present in the second para, which discusses one side of Bowen's research that scientists found differences in the genetic makeup of turtles from various areas.

Thus answer is C is the correct answer.

Hope This Helps.
Thanks.

bm2201  Thanks for the explanation. But the question emphasizes "rarely" interbreed. It seems like C mentions that interbreed is a normal phenomenon, not a rare phenomenon. And From B, "One of eight" represents a rare phenomenon, and "shared a genetic pattern" represents interbreed if I understand sentences correctly.

bM22 · Answer

bm2201  Thanks for the explanation. But the question emphasizes "rarely" interbreed. It seems like C mentions that interbreed is a normal phenomenon, not a rare phenomenon. And From B, "One of eight" represents a rare phenomenon, and "shared a genetic pattern" represents interbreed if I understand sentences correctly.

Hi  Adambhau ,

Option C doesn't imply that the interbreed is a normal phenomenon, it actually implies that since there were distinct differences in the genetic makeup of turtles from various areas that led scientists to theorize that that green turtles rarely interbreed.

Can also be inferred from the 2nd para: The  existence of variations in DNA among geographically distinct groups has helped scientists evaluate the different theories of the mating habits of the green turtle.  Their findings, Bowen asserts, lend credence to the “natal homing” theory. This theory holds that while reptiles born in different regions may share common feeding grounds away from home,  the animals part company at breeding time, each swimming hundreds or thousands of miles to breed and nest at its own birthplace.

Hope This Helps.
Thanks.

egmat · Answer

Hi there,

Passage Overview:  This passage introduces Brian Bowen's novel approach of using  mitochondrial DNA analysis  (instead of traditional tagging) to track green turtles across  four  Atlantic/Caribbean breeding sites. His findings show genetically distinct populations at different sites, lending support to the  "natal homing" theory —that turtles return to their birthplaces to breed. However, the passage notes caveats:  two  sites had indistinguishable DNA, and  one  Aves Island turtle matched a different site's pattern.

Question 1 (Inference): 
  Correct Answer: A  
The passage states that " one  of  eight  study turtles from Aves Island... showed the same genetic pattern as the Tortuguero and Hutchinson turtles." This means the other  seven  did NOT share that pattern—they had distinct genetic patterns. Choice C is the opposite (it says ALL exhibited similar patterns), and E is a  trap  since Aves Island is off Venezuela, so those turtles ARE from Venezuela.

Question 2 (Primary Purpose): 
  Correct Answer: B  
The passage presents Bowen's new idea (using DNA instead of tagging to track turtles) along with data from  four  breeding sites. It does not disprove an existing theory (A), nor does it establish "infallibility" (C)—in fact, the passage includes caveats. Choice D is  tempting , but "confirm the validity" is too strong; the passage says the findings "lend credence" while acknowledging limitations.

Question 3 (Detail Application): 
  Correct Answer: B  
Bowen's research found genetically distinct populations at different breeding sites, which directly tells us whether extensive interbreeding occurs (it doesn't, since the populations remain genetically distinct). Choice A is  tricky —the passage mentions social mixing as a possibility but doesn't definitively answer whether it occurs. The passage cannot answer D (tagging effects on mating) or E (the mechanism of navigation).

Question 4 (Detail): 
  Correct Answer: D  
The passage explicitly states that the existence of DNA variations among geographically distinct groups helped scientists evaluate mating theories and that the findings "lend credence to the  'natal homing' theory ." This directly matches giving "some validity" to the theory.  Note:  it doesn't "discredit" previous notions (B)—it supports one of the existing theories.

Question 5 (Detail/Function): 
  Correct Answer: B  
The first paragraph explicitly states Bowen was "seeking an alternative tracking method" to the traditional approach of tagging animals. Choice A is  tempting but goes beyond what's stated —the passage never mentions concern about interfering with natural routines. Choice C is wrong because no specific difficulties with tagging are mentioned.

Question 6 (Strengthen): 
  Correct Answer: D  
  Key Insight:  A key caveat weakening the natal homing theory is that turtles from Hutchinson Island and Tortuguero had "indistinguishable mitochondrial DNA."  If new tests found subtle differences between these  two  populations (Choice D), that would remove this weakness and strengthen the theory that each population is genetically distinct and returns to its own birthplace. Choice A would actually  weaken  the theory by suggesting interbreeding doesn't blur genetic lines.

Question 7 (Detail): 
  Correct Answer: C  
If turtles from different areas have different genetic makeups, this supports the idea they rarely interbreed—because frequent interbreeding would homogenize their genetics. Choice A actually undermines this contention (shared DNA suggests possible mixing). Choice B shows a rare exception rather than supporting the general rule.

Researchers traditionally have attempted to track animals by tagging

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Researchers traditionally have attempted to track animals by tagging

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