Mayflies (Order Ephemeroptera): Undergo synchronized, massive seasonal emergences of winged adults near aquatic freshwater habitats. The shedding exuviae, wing fragments, and hair particulate from millions of decaying adults become airborne, triggering severe seasonal inhalational allergies (asthma and rhinitis) in humans. (Correct answer)
Stick insects (Phasmatodea): Solitary, camouflaged foliage-feeding insects that do not undergo synchronized massive aerial emergences.
Earwigs (Order Dermaptera): Nocturnal ground-dwelling scavengers that hide in crevices and do not engage in synchronized mass swarm flights.
Praying mantis (Order Mantodea): Solitary, beneficial predatory insects that do not produce airborne allergen swarms.
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13
ICAR JRF Sericulture 29 Jun 2024Shift 1
MCQ (Single Correct)+4−1
EDV (Essentially Derived Varieties) are those which are derived from
Essentially Derived Variety (EDV): Under international plant breeders' rights (UPOV and PPV&FR Act), an EDV is defined as a variety predominantly derived from an initial variety, retaining its essential genotype characteristics, generated through genetic engineering (transformation), induced mutation, somaclonal variation, or repeated backcrossing. (Correct answer)
Crossing two commercial varieties: Represents standard conventional hybridization that generates new recombinant genetic combinations, not an EDV.
Introduced hybrid: Represents an exotic germplasm introduction.
Wide hybridization with wild relatives: Pre-breeding introgression, not an EDV.
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14
ICAR JRF Sericulture 29 Jun 2024Shift 1
MCQ (Single Correct)+4−1
Which nutrient is often a limiting factor in agricultural production?
Nitrogen (N): The primary macronutrient that is most widely deficient and universally limiting for crop growth and yield across virtually all agro-climatic zones and soil orders in India. (Correct answer)
Carbon: Readily acquired by plants from atmospheric carbon dioxide ($CO_2$) during photosynthesis and is not a soil-supplied mineral limiting nutrient.
Oxygen: Absorbed freely from air and soil pore spaces during root respiration and is not a limiting mineral fertilizer element.
Hydrogen: Supplied in abundant quantities through water ($H_2O$) absorbed by roots during transpirational uptake.
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Calcareous or alkaline soils: Under high pH ($pH \gt 7.5$) and abundant free calcium carbonate ($CaCO_3$), iron precipitates into insoluble ferric hydroxides and carbonates ($Fe(OH)_3$), severely reducing bioavailable $Fe^{2+}$ and triggering characteristic lime-induced iron chlorosis in young leaves. (Correct answer)
Salt affected soils: Primarily induce osmotic drought and specific ion toxicities (excess $Na^+$ and $Cl^-$).
Acidic soils: Low pH increases iron solubility, frequently causing iron toxicity rather than deficiency.
Neutral soils: Offer optimal micronutrient availability without precipitation.
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