2024 CSAT — Q53

Locate. This asks for the best-supported inference: find the line that states the finding’s significance and read the practical message off it. The passage: caterpillars’ frass makes the corn plant “turn off its defence,” letting them eat more — and “The find could throw new light on compounds associated with plant response to pathogens like fungi or bacteria.” The forward-looking line is about plant response to microbial pathogens.

Test (find-the-line-then-match). Insight into how plants respond to fungi and bacteria points toward compounds that act on microbes — i.e., antimicrobial compounds. (b) tracks the “pathogens like fungi or bacteria” line directly.

Eliminate by anatomy. (a) gets the direction backwards — the caterpillars eat the corn (the crop), so deploying them would damage crops, not clear weeds; the biology is flipped. (c) is a claim the passage never actually makes — “pesticides” reframes a finding about plant defence/pathogen response as pest-killing chemicals, which the passage does not discuss. (d) is a claim the passage never actually makes — “genetically modified… predators of other pests” invents an application absent from the text. The transferable rule: the practical message must hang off the passage’s own forward line (“compounds associated with plant response to pathogens”) — not a different agricultural use. Key: (b).

“The find could throw new light on compounds associated with plant response to pathogens like fungi or bacteria” — light on plant responses to fungi/bacteria points toward antimicrobial compounds, so the practical message is (b). (a) reverses the biology (the caterpillars eat the CROP, not weeds); (c) “pesticides” is not what the find is about (it concerns turning off plant defence / pathogen response, not pest-killing chemicals); (d) “genetically modified… predators” is nowhere in the text.

The passage reports that caterpillar frass switches off the corn plant’s anti-insect defence, and that the finding “could throw new light on compounds associated with plant response to pathogens like fungi or bacteria.” Understanding plant responses to fungi and bacteria is the route to antimicrobial compounds.

(b) — the finding can help develop clinically useful antimicrobial compounds — is the message the “pathogens like fungi or bacteria” line implies. (a) reverses the biology (caterpillars eat the crop), (c) swaps in “pesticides” (not the passage’s subject), and (d) invents genetic modification.

Answer: (b).

The discriminating line is “compounds associated with plant response to pathogens like fungi or bacteria” — that points to antimicrobial compounds (b), a medical/biological application. Each distractor re-aims the finding at a different, unsupported agricultural use (weed control, pesticides, GM predators). The scoring move is to follow the passage’s own stated significance to its implication, not to substitute a more familiar farming application.