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 Forestry 29 Jun 2024Shift 1
MCQ (Single Correct)+4−1
Movement of DNA from one bacterium to another through a tubular bridge or pilus:
Conjugation: Direct transfer of genetic material (plasmid or chromosomal DNA) from a donor bacterium to a recipient bacterium through physical cell-to-cell contact mediated by a sex pilus (conjugation tube). (Correct answer)
Transposition: Movement of discrete mobile genetic elements called transposons ("jumping genes") from one genomic location to another within the same cell, catalyzed by transposase.
Transfection: Artificial introduction of foreign naked nucleic acids (DNA or RNA) into eukaryotic host cells using non-viral chemical or physical techniques.
Transduction: Horizontal gene transfer between bacterial cells mediated by a bacteriophage (viral vector), occurring without direct physical contact between the bacteria.
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14
ICAR JRF Forestry 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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15
ICAR JRF Forestry 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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