Agriculture 2022 Paper II 50 marks 150 words Compulsory Describe

Q1

Answer the following questions in about 150 words each: 10×5=50 (a) What is polyploidy? Give a brief account of classification of polyploids. (b) What are the applications of mass selection in self-pollinated crops? Describe its merits and demerits. (c) What do you understand by the vertical and horizontal disease resistance in crop plants? (d) Define seed quality. Describe the characteristics of a seed which decide its quality. (e) Define matric potential, osmotic potential and turgor potential, and explain their interrelationships with water potential.

हिंदी में प्रश्न पढ़ें

निम्नलिखित प्रश्नों में से प्रत्येक का उत्तर लगभग 150 शब्दों में दीजिए : 10×5=50 (क) बहुगुणिता क्या है? बहुगुणित (पॉलीप्लॉइड) के वर्गीकरण का संक्षिप्त विवरण दीजिए। (ख) स्वयं-परागित फसलों में सामूहिक चयन के अनुप्रयोग क्या हैं? इसके गुणों और दोषों का वर्णन कीजिए। (ग) फसलीय पौधों में उद्वधिर एवं क्षैतिज रोग प्रतिरोध से आप क्या समझते हैं? (घ) बीज गुणवत्ता को परिभाषित कीजिए। बीज की गुणवत्ता को निर्धारित करने वाले गुणों का वर्णन कीजिए। (ङ) मैट्रिक विभव (पोटेंशियल), परासरणी विभव और स्फीति विभव को परिभाषित कीजिए एवं जल विभव से इनके अंतर्संबंधों की व्याख्या कीजिए।

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Directive word: Describe

This question asks you to describe. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.

See our UPSC directive words guide for a full breakdown of how to respond to each command word.

How this answer will be evaluated

Approach

This multi-part descriptive question requires approximately 30 words per sub-part (150 words total). Spend roughly equal time (~20%) on each sub-part since marks are evenly distributed. Structure each answer as: precise definition → classification/characteristics → brief example where applicable. For (e), include the equation Ψw = Ψs + Ψp + Ψm as the core explanatory framework.

Key points expected

(a) Polyploidy: Definition (more than two complete sets of chromosomes); Classification into autopolyploids (same genome, e.g., autotriploid, autotetraploid) and allopolyploids (different genomes, e.g., amphidiploids); mention of euploidy vs. aneuploidy distinction
(b) Mass selection in self-pollinated crops: Applications (purifying varieties, handling landraces, creating synthetic varieties); Merits (simple, low cost, maintains genetic variability); Demerits (slow genetic gain, cannot exploit heterosis, limited for highly heritable traits)
(c) Vertical vs. Horizontal resistance: Vertical (race-specific, oligogenic, follows gene-for-gene hypothesis, boom-bust cycle); Horizontal (race-nonspecific, polygenic, durable, partial resistance); mention of Van der Plank's classification
(d) Seed quality: Definition (sum of genetic, physical, physiological, and health attributes); Characteristics (genetic purity, physical purity, germination percentage, vigour, moisture content, seed health, uniformity)
(e) Water potential components: Matric potential (Ψm, binding forces in soil/matrix); Osmotic/solute potential (Ψs, effect of dissolved solutes, always negative); Turgor/pressure potential (Ψp, wall pressure, usually positive); Interrelationship: Ψw = Ψs + Ψp + Ψm (Ψm often negligible in cells)

Evaluation rubric

Dimension	Weight	Max marks	Excellent	Average	Poor
Concept correctness	25%	12.5	All five sub-parts demonstrate precise scientific accuracy: (a) correctly distinguishes auto- vs. allopolyploidy with ploidy level notation; (b) accurately identifies mass selection's specific utility for self-pollinators vs. cross-pollinators; (c) correctly applies Van der Plank's terminology and gene-for-gene concept; (d) covers all four seed quality dimensions per ISTA/NSC standards; (e) states the complete water potential equation with correct sign conventions	Most definitions are correct but with minor errors: (a) confuses auto- and allopolyploidy examples; (b) applies mass selection generically without self-pollinator specificity; (c) mixes vertical/horizontal characteristics; (d) omits one quality dimension; (e) misses Ψm or sign errors in equation	Fundamental conceptual errors: (a) defines polyploidy as simply 'more chromosomes' without ploidy concept; (b) describes mass selection for hybrid development; (c) reverses vertical/horizontal resistance meanings; (d) conflates seed quality with grain quality; (e) states Ψw = Ψs + Ψp without understanding component meanings
Quantitative reasoning	15%	7.5	(a) Uses correct ploidy notation (2n, 3x, 4x, 2n=4x=48 for wheat); (e) presents the equation Ψw = Ψs + Ψp + Ψm with typical values (Ψs = -0.5 to -2.0 MPa, Ψp = 0.1-0.5 MPa, Ψw = -0.3 to -1.5 MPa for turgid cells); mentions that Ψm ≈ 0 in hydrated cells; (d) cites standard germination percentages (90%+ for certified seed)	Mentions ploidy levels without systematic notation; states water potential equation but without numerical illustration; gives generic 'high germination' without percentage benchmarks; no quantitative treatment in other parts	No quantitative content; avoids equations entirely; gives vague qualitative descriptions where numerical precision is expected; confuses units (bars vs. MPa vs. atm) in water relations
Indian context examples	20%	10	(a) Cites Indian examples: Triticum aestivum (hexaploid, 2n=6x=42) and T. durum (tetraploid, 2n=4x=28); Saccharum officinarum × S. spontaneum hybrids for sugarcane; (b) References mass selection in Indian landraces like 'Rajendra' wheat varieties; (c) Mentions wheat rust resistance in India (Lr genes for vertical, Sr2 complex for horizontal); (d) Cites NSC/NSC(SF) standards or state seed certification agencies; mentions hybrid seed production in cotton/mustard	Generic crop examples without Indian specificity (e.g., 'wheat' not 'Triticum aestivum'); mentions Indian agricultural context superficially without named varieties or institutions; no reference to ICAR/SAUs breeding programmes	No Indian examples; uses exclusively foreign references (e.g., only US corn, European wheat); ignores indigenous germplasm and breeding achievements; fails to mention NBPGR, ICAR, or state agricultural universities
Diagram / process	20%	10	(e) Includes a clear diagram showing water potential components with reference to standard (pure water at atmospheric pressure = 0) and typical cell values; (a) may include chromosome set diagram for auto- vs. allopolyploidy; (c) shows gene-for-gene interaction schematic; descriptions use process language (how mass selection cycles proceed, how resistance mechanisms operate)	Describes diagrams verbally without sketching; uses flowchart-style description for processes; mentions 'as shown in figure' without actual figure; process descriptions are sequential but lack mechanistic detail	No diagrammatic intent; purely textual answers; no process description (static definitions only); fails to describe interrelationships in (e) visually or structurally
Policy / extension angle	20%	10	(d) Links seed quality to Seed Act 1966, Seed Rules 1968, and 2002 amendment; mentions Seed Certification Agency, truth-in-labelling; (b) Discusses mass selection's relevance for participatory plant breeding and farmer seed systems; (c) Connects horizontal resistance to sustainable agriculture and reduced fungicide use; mentions ICAR's All India Coordinated Research Projects; (e) Relates water potential to irrigation scheduling and drought management extension	Mentions seed certification or quality standards generically; references 'government policy' without specificity; acknowledges extension relevance without elaborating mechanism; no integration of breeding objectives with national food security	No policy or extension content; treats all sub-parts as purely academic exercises; ignores farmer-level implications, seed industry, or regulatory frameworks; no mention of PM-KISAN, National Seed Mission, or climate adaptation strategies

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