Passage: In the late nineteenth century, botanists generally viewed mycorrhizal fungi—asso… — GMAT

Passage:
In the late nineteenth century, botanists generally viewed mycorrhizal fungi—associations between soil fungi and plant roots—as purely parasitic organisms that extracted carbohydrates without benefiting their host plants. However, the pioneering studies of Albert Bernhard Frank in the 1880s challenged this paradigm by demonstrating that ectomycorrhizal fungi actively facilitate nutrient uptake, particularly nitrogen and phosphorus, in forest trees. Subsequent research in the mid-twentieth century broadened this view, revealing that mycorrhizal networks also facilitate inter-plant nutrient transfer and mediate plant defense signaling against pathogens.

Despite these advancements, early twentieth-century forestry management programs routinely disregarded fungal symbiosis when establishing nursery plantations in deforested regions. Managers frequently sterilized soil to eliminate pathogenic microbes, unwittingly destroying beneficial mycorrhizal inocula. Consequently, seedlings cultivated in these sterile substrates exhibited stunted growth and high mortality rates when transplanted to nitrogen-deficient soils. It was not until experimental reintroduction of forest humus restored seedling vigor that foresters acknowledged the indispensable role of mycorrhizal fungi in terrestrial ecosystem restoration.

According to the passage, all of the following were true regarding early twentieth-century forestry management practices EXCEPT:

Forestry managers intentionally inoculated nursery soils with fungal spores to foster defense signaling in seedlings.Cevap
B
Soil sterilization procedures inadvertently destroyed beneficial fungi alongside target pathogenic microbes.
C
Seedlings grown in sterilized substrates suffered from high mortality rates after being transplanted into nitrogen-deficient soils.
D
Forestry management programs initially failed to account for fungal symbiosis during the establishment of nursery plantations.
E
The restoration of seedling vigor was observed following the experimental reintroduction of forest humus to the nursery soil.

Cevap

The statement claiming that forestry managers intentionally inoculated nursery soils with fungal spores to foster defense signaling in seedlings is NOT supported by the passage.

The correct answer is the choice stating that forestry managers intentionally inoculated nursery soils with fungal spores to foster defense signaling in seedlings. The passage contradicts this by stating that early twentieth-century managers routinely disregarded fungal symbiosis and sterilized soil to kill pathogens, destroying beneficial inocula rather than adding them.

Adım Adım Çözüm

Identify the question type and objective.

The prompt is a Negative Factual / EXCEPT question. The goal is to identify the single choice that is contradicted by or unmentioned in the passage, while four incorrect choices will be true statements based on the text.

Negative factual questions require systematic elimination of options directly supported by the passage text.

Scan the passage for details regarding early twentieth-century forestry management practices.

The second paragraph describes early twentieth-century practices: managers routinely disregarded fungal symbiosis, sterilized soil to eliminate pathogens (unwittingly destroying mycorrhizae), observed stunted growth and high mortality in nitrogen-deficient soils, and eventually restored seedling vigor through the experimental reintroduction of forest humus.

Targeting the specific paragraph addressing forestry management provides the evidentiary basis for evaluation.

Evaluate each option against the passage details.

The option stating that managers intentionally inoculated nursery soils directly contradicts the passage text, which indicates that managers routinely disregarded fungal symbiosis and sterilized soil to eliminate microbes.

Direct contradiction makes this option the false claim, making it the correct answer for an EXCEPT question.

Anahtar Kavram

Negative Factual / EXCEPT Questions in Reading Comprehension

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