Reading Comprehension

PT145 · S1 · P4 · Q23 Genetic Typos

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The French biologist Jean-Baptiste de Lamarck (1744–1829) outlined a theory of evolutionary change in 1809, 50 years before Darwin’s On the Origin of Species.

Topic

The revival of Lamarckian evolutionary theory through new research on heredity in the immune system.

Framework

Old / New; Present Debate

Main Point

Edward J. Steele and his team are challenging the widely dismissed Lamarckian theory of evolution by proposing that a mechanism in the immune system could allow acquired traits to be inherited, although most biologists remain skeptical due to lack of direct evidence. ( — End of P1 gives the core new idea, while P4 presents ongoing skepticism and the debate.)

P1: Introduction to Lamarck and Steele's Revival

Lamarck, a French biologist, suggested in 1809 that organisms could inherit traits acquired during their lifetimes. While this idea has been mostly laughed off by modern biologists, Edward J. Steele is now trying to bring Lamarckism back, claiming he’s found supporting evidence in how our immune system works.

P2: The Immune System’s Mutating Genes

This paragraph lays out the mystery of how the immune system adapts so quickly to new threats—partly by certain cells mutating their genes at an unusually high rate, creating "typos" as the DNA is copied to RNA. This enables the immune system to experiment with defenses on the fly.

P3: Steele’s Lamarckian Hypothesis and Its Mechanism

Here we get the details of Steele’s theory: he proposes that altered RNA is turned back into DNA (a process called "reverse transcription"), and suggests that viruses could carry this altered DNA into reproductive cells—potentially passing acquired traits to offspring.

23.

The passage is primarily concerned with

offering a historical account of
Opposite
This is not primarily about the Old history, it's about the New claims from Steele and his colleagues. This answer is playing the trap answer game of leaning too heavily on the first few sentences. The author discusses Lamarck as some warm-up context. But the Purpose Pivot in the final sentence of the 1st paragraph (but, yet, however, recently) shows us the foreground of the passage is really Steele's present day science.
1% picked this
Correct
describing the efforts of a
Why this is right
This works, since the "modern biologist" is Steele, and his team's research and claims are the central topic of the whole passage. Is he trying to vindicate a long-disregarded evolutionary theory? According to the thesis sentence (the final sentence of the first paragraph), he is "attempting to revive Lamarckism", and Lamarckism is definitely a long-disregarded evolutionary theory. Since 1809, when Lamarck outlined his theory, he's been ridiculed and most modern biologists are adamant that nothing of the sort he describes occurs, ever. So we can read this answer as "the passage is primarily concerned with describing the efforts of Steele to revive Lamarckism", which seems very on point.
Skill tested: Primary Purpose · how this choice captures the passage's function is the move to repeat next time.
78% picked this
answering a set of questions
Wrong Emphasis: immune system
This answer makes it seem like this passage was primarily about the immune system, when instead it was primarily about Steele's research, which is not even alluded to in this answer choice.
3% picked this
evaluating the overall merits of
Wrong Emphasis: Lamarck
The evolutionary theory that has been rejected by most modern biologists is Lamarck's evolutionary theory. So this answer makes it seem like the passage was mainly about evaluating the merits of Lamarck's theory, when in reality it was about considering Steele's attempt to revive the concept that acquired traits can be passed onto offspring.
17% picked this
presenting a discredited evolutionary theory
Wrong Emphasis: Lamarck
The evolutionary theory that has been discredited is Lamarck's evolutionary theory. So this answer makes it seem like the passage was mainly about presenting Lamarck's theory as a case study in the philosophy of science, but the main topic was actually Steele's new claims that he's found evidence in the immune system for a way that we could pass acquired traits to our offspring.
1% picked this

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