Logical Reasoning

PT109 · S4 · Q14 When soil is plowed in the spring

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When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface.

Statements

There's a Causal Chain type story presented:

1. buried in the soil all winter 2. churned up to surface when soil is plowed in the spring 3. gets brief exposure to sunlight 4. receptors get stimulated 5. receptors trigger germination

The final idea is a Conditional that says

if not 1 → then 3 doesn't trigger 4

Technically, it's "if there isn't prolonged darkness", then 3 doesn't trigger 4. Being buried all winter is one way to get prolonged darkness, but there are presumably other ways (f.e. watching French films, I'd imagine)

For the last sentence, I would primarily remember it as a Causal Difference-Maker: the long exposure to darkness is what makes the receptors sensitive enough to get triggered by brief sunlight

It's kinda like, .

Goal

The question stem is about pigweed seeds in the exact situation we just had described to us, so it seems like it's just asking us what we can best prove from the paragraph.

We'd expect them, when plowed, to receive brief sunlight, and if they do, and they've truly been exposed to prolonged darkness over the winter, then we expect them to germinate. Otherwise, we'd expect them not to germinate.

14.

The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?

  1. Correct

    Fewer pigweed plants will grow

    Why this is right

    This answer plays off the Causal Difference-Maker said in the final sentence: if the seeds don't have that special recipe of Prolonged Darkness followed by Sunlight Exposure, they don't germinate. So plowing during the day would expose those seeds to sunlight, sparking their germination. Plowing during the night would churn up all those seeds, but they wouldn't get any exposure to sunlight, so their receptors wouldn't trigger germination. Since a plant needs to germinate in order to grow (they're counting on us to have this common knowledge), you'd get more plants if you plow during the day than if you plow at night.

    Skill tested: Most Supported · how this choice captures the argument's function is the move to repeat next time.

    65% picked this

  2. Fewer pigweed plants will grow

    Opposite

    The syntax of this one is not agreeing with me. I just don't understand how that's grammatically or logically acceptable. It sounds like it's comparing a situation in which we plow "at least once, day or night" to a situation in which we plow "at night, if ever". We know from our thinking through (A) that if this field is plowed at night, the seeds won't be exposed to sunlight, so the receptors won't trigger germination, and no pigweed will grow. So since we know that none of them will grow if plowed only at night, then it's impossible for any situation to have fewer pigweed plants than zero.

    3% picked this

  3. Fewer pigweed plants will grow

    Unknown Comparison

    Which has more sunlight: the pinkish aurora before sunrise, or the pinkish hues around dusk? Naturally, we don't know and they're probably pretty similar, since they're opposite functions of each other. So we can't say that just before sunrise is dimmer than just after sunset, and the only way to justify fewer/greater pigweed plants is to establish less/more exposure to direct sunlight.

    6% picked this

  4. The pigweed seeds that are

    Too Strong: unless

    We only have one rule provided that allows us to say "therefore, won't germinate", and that's the idea that "they weren't in prolonged darkness followed by exposure to sunlight". We were told that the seeds are redeposited beneath the surface, not that they need to be redeposited.

    24% picked this

  5. All of the pigweed seeds

    Contradicted

    The seeds that are already on the surface haven't had the required prolonged darkness that the seeds that were buried all winter had. Without the "long darkness + sunlight exposure" cocktail, the seeds don't germinate.

    2% picked this

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