Although many transposons, DNA sequences that move within an organism's genome through shuffling or duplication, have become corrupted and inactive...
GMAT Information and Ideas : (Ideas) Questions
Although many transposons, DNA sequences that move within an organism's genome through shuffling or duplication, have become corrupted and inactive over time, those from the long interspersed nuclear elements (LINE) family appear to remain active in the genomes of some species. In humans, they are functionally important within the hippocampus, a brain structure that supports complex cognitive processes. When the results of molecular analysis of two species of octopus—an animal known for its intelligence—were announced in 2022, the confirmation of a LINE transposon in Octopus vulgaris and Octopus bimaculoides genomes prompted researchers to hypothesize that that transposon family is tied to a species' capacity for advanced cognition.
Which finding, if true, would most directly support the researchers' hypothesis?
The LINE transposon in O. vulgaris and O. bimaculoides genomes is active in an octopus brain structure that functions similarly to the human hippocampus.
The human genome contains multiple transposons from the LINE family that are all primarily active in the hippocampus.
A consistent number of copies of LINE transposons is present across the genomes of most octopus species, with few known corruptions.
O. vulgaris and O. bimaculoides have smaller brains than humans do relative to body size, but their genomes contain sequences from a wider variety of transposon families.
Step 1: Decode and Map the Passage
Part A: Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "Although many transposons, DNA sequences that move within an organism's genome through shuffling or duplication, have become corrupted and inactive over time," |
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| "those from the long interspersed nuclear elements (LINE) family appear to remain active in the genomes of some species." |
|
| "In humans, they are functionally important within the hippocampus, a brain structure that supports complex cognitive processes." |
|
| "When the results of molecular analysis of two species of octopus—an animal known for its intelligence—were announced in 2022," |
|
| "the confirmation of a LINE transposon in Octopus vulgaris and Octopus bimaculoides genomes prompted researchers to hypothesize that that transposon family is tied to a species' capacity for advanced cognition." |
|
Part B: Passage Architecture & Core Elements
Main Point: The discovery of LINE transposons in intelligent octopus species has led researchers to hypothesize that these active genetic elements are connected to advanced cognitive abilities.
Argument Flow: The passage moves from general background about inactive transposons to the special case of active LINE transposons. It establishes their importance in human cognition through their presence in the hippocampus, then introduces parallel evidence from octopuses—another intelligent species—to support a broader hypothesis linking LINE transposons to advanced cognition across species.
Step 2: Interpret the Question Precisely
What's being asked? We need to identify which finding would most directly support the researchers' hypothesis.
What type of answer do we need? Evidence that would strengthen the specific claim that LINE transposon family is tied to advanced cognition.
Any limiting keywords? "most directly support" means we want the strongest, most relevant evidence for this particular hypothesis.
Step 3: Prethink the Answer
- The hypothesis claims that LINE transposons are connected to advanced cognition
- For this to be supported, we need evidence that:
- Shows LINE transposons are actually active (not just present) in cognitive brain regions
- Connects the octopus findings to brain function, similar to what we know about humans
- Demonstrates a functional relationship between LINE transposons and cognition in the octopus species mentioned
- So the right answer should show that the LINE transposons found in these intelligent octopuses are active in brain structures related to cognition, paralleling what we see in humans
The LINE transposon in O. vulgaris and O. bimaculoides genomes is active in an octopus brain structure that functions similarly to the human hippocampus.
- This directly parallels the human evidence from the passage
- Shows LINE transposons are active (not just present) in octopus cognitive brain structures
- Creates a clear connection between the genetic finding and brain function
The human genome contains multiple transposons from the LINE family that are all primarily active in the hippocampus.
- Focuses only on human LINE transposons, not the octopus findings
- Doesn't connect the octopus research to cognition
A consistent number of copies of LINE transposons is present across the genomes of most octopus species, with few known corruptions.
- Shows consistency across octopus species but says nothing about brain function
- Presence doesn't equal activity or cognitive connection
O. vulgaris and O. bimaculoides have smaller brains than humans do relative to body size, but their genomes contain sequences from a wider variety of transposon families.
- Discusses brain size and variety of transposons, not LINE transposons specifically
- Doesn't connect to cognitive function or support the LINE-cognition hypothesis