Poison frogs become poisonous by isolating chemicals from their food and storing them in their skin. One such compound, epibatidine, is a stronger painkiller than morphine, but has not been tested in humans because even low doses are deadly to rodents. But for the frogs themselves, this powerful neurotoxin is totally impotent. According to a study published in Science, several groups of epibatidine-bearing frogs have independently evolved amino acid changes in the toxin's target, the nicotinic acetylcholine receptor. These modifications allow the amphibians to escape self-toxicity.
The main idea of the passage is that some types of poison frogs:
- A. have developed the capacity to protect themselves from the poison they carry in their skin
- B. could eventually produce a natural pain relief option for people who suffer from headaches
- C. combine chemicals from their food to create a toxic substance that keeps them safe from predators
- D. can be grouped based on the changes they've made to their nicotinic acetylcholine receptors
Correct Answer & Rationale
Correct Answer: A
Option A highlights the unique adaptation of certain poison frogs, emphasizing their ability to protect themselves from their own toxins. This reflects a key aspect of their survival strategy. Option B, while interesting, suggests a potential human application of frog toxins that is not the main focus of the passage. Option C inaccurately attributes the creation of toxins solely to food sources, overlooking the frogs' inherent toxic traits. Option D focuses on a specific biological mechanism that, while relevant, does not encapsulate the broader theme of self-protection central to the passage.
Option A highlights the unique adaptation of certain poison frogs, emphasizing their ability to protect themselves from their own toxins. This reflects a key aspect of their survival strategy. Option B, while interesting, suggests a potential human application of frog toxins that is not the main focus of the passage. Option C inaccurately attributes the creation of toxins solely to food sources, overlooking the frogs' inherent toxic traits. Option D focuses on a specific biological mechanism that, while relevant, does not encapsulate the broader theme of self-protection central to the passage.
Other Related Questions
Which choice best replaces the underlined portion in sentence 6 (reproduced below) to suggest that, for a time, people were completely caught up with news of the Leonid meteor shower? In the center of the quilt, the 'falling of the stars' illustrates the hours-long Leonid meteor shower that interested people on November 13, 1833.
- A. affected
- B. enthralled
- C. involved
- D. worried
Correct Answer & Rationale
Correct Answer: B
The term "enthralled" effectively conveys a sense of deep fascination and engagement, suggesting that people were completely captivated by the Leonid meteor shower. Option A, "affected," lacks the intensity and emotional connection implied in the context; it merely indicates a change rather than a strong interest. Option C, "involved," suggests participation but does not capture the sense of wonder that the meteor shower inspired. Option D, "worried," introduces an inappropriate negative connotation, as the context is one of excitement and awe, not concern.
The term "enthralled" effectively conveys a sense of deep fascination and engagement, suggesting that people were completely captivated by the Leonid meteor shower. Option A, "affected," lacks the intensity and emotional connection implied in the context; it merely indicates a change rather than a strong interest. Option C, "involved," suggests participation but does not capture the sense of wonder that the meteor shower inspired. Option D, "worried," introduces an inappropriate negative connotation, as the context is one of excitement and awe, not concern.
In context, which word or phrase is best to insert at the beginning of sentence 11? Sentence 11: He spent most of his time writing poems in Spanish instead of studying English.
- A. In addition.
- B. For example.
- C. However.
- D. Indeed.
Correct Answer & Rationale
Correct Answer: C
The choice of "However" effectively contrasts the subject's choice to write poems in Spanish with the expectation that he should be studying English. This juxtaposition highlights a shift in focus, emphasizing the divergence from expected behavior. Option A, "In addition," suggests continuity rather than contrast, which does not align with the sentence's intent. Option B, "For example," implies that the sentence will provide an instance, which is not the case here. Option D, "Indeed," reinforces a statement rather than introducing a contrasting idea, making it unsuitable for the context.
The choice of "However" effectively contrasts the subject's choice to write poems in Spanish with the expectation that he should be studying English. This juxtaposition highlights a shift in focus, emphasizing the divergence from expected behavior. Option A, "In addition," suggests continuity rather than contrast, which does not align with the sentence's intent. Option B, "For example," implies that the sentence will provide an instance, which is not the case here. Option D, "Indeed," reinforces a statement rather than introducing a contrasting idea, making it unsuitable for the context.
In the passage, the author refers to the photography technique of double exposure primarily to:
- A. Explain that Rodriguez frequently uses that technique to create eerie and distorted representations of city life
- B. Illustrate how Rodriguez's innovative use of double exposure inspired other photographers to do so as well
- C. Provide an example of how Rodriguez explored the tension between his identity as a photographer and as a scholar
- D. Set up a metaphor comparing that technique to the way Rodriguez's work depicts the duality of Los Angeles
Correct Answer & Rationale
Correct Answer: D
The reference to double exposure serves as a metaphor for the duality of Los Angeles, highlighting the complexity and contrasting elements within the city. This choice effectively encapsulates Rodriguez's artistic vision, illustrating how his work reflects both the vibrant and shadowy aspects of urban life. Option A inaccurately suggests a focus on Rodriguez's frequent use of the technique rather than its metaphorical significance. Option B misinterprets the intent, as the passage emphasizes Rodriguez's personal exploration rather than his influence on others. Option C, while relevant, does not capture the primary purpose of the metaphor, which centers on the depiction of duality rather than identity tension.
The reference to double exposure serves as a metaphor for the duality of Los Angeles, highlighting the complexity and contrasting elements within the city. This choice effectively encapsulates Rodriguez's artistic vision, illustrating how his work reflects both the vibrant and shadowy aspects of urban life. Option A inaccurately suggests a focus on Rodriguez's frequent use of the technique rather than its metaphorical significance. Option B misinterprets the intent, as the passage emphasizes Rodriguez's personal exploration rather than his influence on others. Option C, while relevant, does not capture the primary purpose of the metaphor, which centers on the depiction of duality rather than identity tension.
Which is the best way to revise and combine sentences 3 and 4 (reproduced below)? Lorca was the oldest son of a wealthy landowner. He studied literature and law at the University of Granada before turning to writing full-time.
- A. Lorca was the oldest son of a wealthy landowner, studied literature and law at the University of Granada before turning to writing full-time.
- B. The oldest son of a wealthy landowner, Lorca studied literature and law at the University of Granada before turning to writing full-time.
- C. Lorca, the oldest son of a wealthy landowner, studying literature and law at the University of Granada before turning to writing full-time.
- D. The oldest son of a wealthy landowner who studied literature and law at the University of Granada, Lorca then turning to writing full-time.
Correct Answer & Rationale
Correct Answer: B
Option B effectively combines the two sentences by placing the subject, Lorca, at the beginning and clearly linking his identity to his actions. This structure maintains clarity and coherence, allowing readers to easily follow the progression of ideas. Option A lacks a conjunction, resulting in a sentence fragment that does not convey a complete thought. Option C incorrectly uses "studying," which creates a grammatical error by failing to connect the clauses properly. Option D introduces unnecessary complexity with "who studied," and the phrase "Lorca then turning" is awkward and grammatically incorrect. Thus, option B stands out as the most coherent and grammatically sound choice.
Option B effectively combines the two sentences by placing the subject, Lorca, at the beginning and clearly linking his identity to his actions. This structure maintains clarity and coherence, allowing readers to easily follow the progression of ideas. Option A lacks a conjunction, resulting in a sentence fragment that does not convey a complete thought. Option C incorrectly uses "studying," which creates a grammatical error by failing to connect the clauses properly. Option D introduces unnecessary complexity with "who studied," and the phrase "Lorca then turning" is awkward and grammatically incorrect. Thus, option B stands out as the most coherent and grammatically sound choice.