Q26

[crocca]

How does A strengthen Steele's position? Can someone please review this question and the answer choices.

Thank you in advance!!

[ohthatpatrick]

Question Type:
Strengthen/Weaken

Answer expected in lines/paragraph:
Lines 30-33, 38-43, and 48-55

Any prephrase?
I would try to remind myself of their causal story, so that we can look for any answer that strengthens by adding plausibility to this story. They think that "mutated RNA from immune system --> reverse transcribed into DNA --> virus takes mutated DNA to reproductive cells --> mutated DNA gets into reproductive cells and makes it to next generation". Part of their evidence for this occurring is a distinct pattern of mutations concentrated in particular areas of genes that carry immune responses. So we either need to rule out an alternate explanation for that "distinct pattern of mutations" or strengthen the causal story that gets mutated RNA to the next generation.

Correct answer:
A

Answer choice analysis:

A) This adds credence to their causal story, since part of it was "virus takes mutated DNA to reproductive cells --> mutated DNA gets into reproductive cells and makes it to next generation".

B) This might do more to weaken, since the "signature pattern" is not confined to immune response genes.

C) This is unrelated to the causal chain.

D) Steele is NOT talkin' about giraffes.

E) This looks like it's dealing with the last link in the causal story: "virus takes DNA to reproductive --> mutated virus DNA then makes it to next generation". But -- this is not talking about a mother bird passing mutated DNA to its offspring. It's talking about a mother bird passing acquired immunities to chicks that are gestating. This is analogous to a human mother passing antibodies to her fetus via the placenta. It's not coming from DNA / heredity.

Takeaway/Pattern: In LR, strengthening a causal argument will either Rule Out an Alternative Cause or Add Plausibility to the author's story. In RC, I think we're more likely to see the latter. Mentally rehearse the author's causal story and look for any facts that seem to corroborate any part of it.

#officialexplanation

[EmileeW523]

I got rid of A because I thought that the question in the passage "does it ever occur?" in the last paragraph was enough to suggest that it is important that the transfer in DNA to the reproductive system can happen in nature, and because A talks about how it can be done in a laboratory, it still doesn't support Steele's theory well.

I chose E because I assumed that passing on immunity is the same as passing on genes that grants immunity (how else could immunity be passed down, if not through DNA?) Can anyone help?

[ZaftigG65]

I believe E is incorrect because it talks about passing on immunities to another being. It's analogous to someone teaching a subject to a student. However, Steele is primarily concerned with someone changing their own self; their DNA (albeit reproductive DNA). This answer would be correct if the stress was on the hen changing her own yolk content first and then conceiving a chick with the enhancements of the changed yolk.