UPHESC Assistant Professor Botany 2025 PYQs

Concept: Match each disease with its causal organism.

1. Citrus canker – bacterium Xanthomonas citri (a – III).
2. Green ear (downy mildew) of bajra – Sclerospora graminicola (b – IV).
3. Yellow vein mosaic / vein clearing of bhindi – a begomovirus (Bhendi/Hibiscus yellow vein mosaic virus) spread by whitefly (c – II).
4. Rust of linseed – Melampsora lini (printed as 'Melanospora lini') (d – I).

Short trick: Canker–Xantho, Green ear–Sclero, Bhindi–whitefly virus, Linseed rust–Melampsora.

Concept: Each major system was built on an earlier one.

1. Bentham & Hooker (1862–83) – a natural system modelled on de Candolle's (a – I).
2. Engler & Prantl (1887–1915) – elaborated Eichler's (1883) system (b – III).
3. Hutchinson (1926, 1959) – based on Bessey's 'dicta' (Ranalian, woody vs herbaceous lines) (c – II).
4. Takhtajan – very similar to Cronquist's system; both derive from the Magnoliid (Ranalian) concept and were developed in parallel (d – IV).

Short trick: B&H←de Candolle, Engler←Eichler, Hutchinson←Bessey, Takhtajan≈Cronquist.

Concept: Wheat has three rusts, each by a different Puccinia species.

1. Black (stem) rust – Puccinia graminis f.sp. tritici (printed 'graminicola') (a – II).
2. Yellow (stripe) rust – P. striiformis (b – IV).
3. Brown (leaf) rust – P. recondita (= P. triticina) (c – I).
4. Red rot of sugarcane – Colletotrichum falcatum (d – III); it is a rot, not a rust, but it is the only fungus left.

Short trick: Black–graminis, Yellow–striiformis, Brown–recondita; Sugarcane red rot–Colletotrichum.

Concept: Multiple-factor hypothesis (Nilsson-Ehle, East) + Fisher (1918): V_P = V_G + V_E.

1. I ✔ – quantitative traits are controlled by many genes with small additive effects, plus environment.
2. II ✔ – Fisher partitioned phenotypic variance into genetic (additive, dominance, epistatic) and environmental parts.
3. III ✘ – Fisher showed quantitative traits follow Mendelian genes; not solely environmental.
4. IV ✘ – V_T = V_g only if V_e = 0, which is never 'always' true (heritability would always be 1).

Short trick: V_P = V_G + V_E – both parts always count.

Concept: Identify the plant, then its family.

1. Pimpinella anisum – aniseed (saunf-like spice), Apiaceae/Umbelliferae (a – II).
2. Trigonella foenum-graecum – fenugreek (methi), Fabaceae–Papilionaceae (b – IV).
3. Emblica officinalis (Phyllanthus emblica) – amla, Euphorbiaceae (now Phyllanthaceae) (c – I).
4. Elettaria cardamomum – small cardamom, Zingiberaceae (d – III).

Short trick: Anise–Umbel, Methi–Pea, Amla–Euphorb, Elaichi–Ginger.

Concept: Skoog and Miller (1957), working with tobacco pith callus, showed hormonal control of organogenesis.

1. High auxin : cytokinin → roots (rhizogenesis).
2. High cytokinin : auxin → shoots/buds (caulogenesis).
3. Intermediate/balanced ratio → undifferentiated callus growth.
4. O₂, CO₂, GA and ethylene only modify, not decide, the root/shoot fate.

Short trick: Auxin → Root; Cytokinin → Shoot (A-R, C-S).

Concept: Palynology (Hyde & Williams, 1944) studies pollen and spores – living and fossil.

1. I ✔ – fossil pollen in peat/lake sediments reconstructs past vegetation and climate (palaeoclimatology, pollen diagrams).
2. II ✔ – pollen/spore records trace the developmental (evolutionary) history of plant groups, and pollen ontogeny is itself a core topic.
3. IV ✔ – pollen viability, fertility and compatibility tests guide hybridisation in crop breeding.
4. III – 'adaptability of plants' is judged by physiological/ecological trials, not by pollen study – so I, II and IV.

Short trick: Palynology: past climate, plant history, breeding (compatibility) – plus honey, forensics, allergy, oil exploration.

Concept: From Chytrids/Zygomycetes to Ascomycetes and Basidiomycetes the trends are: septation, dikaryon, loss of sex organs, symbioses.

1. 2 ✔ – lower fungi have coenocytic (aseptate) hyphae; Asco- and Basidiomycetes have septate hyphae.
2. 3 ✔ – a dikaryotic phase appears in Ascomycetes (ascogenous hyphae) and dominates the life cycle in Basidiomycetes.
3. 4 ✔ – ectomycorrhizae are formed mainly by advanced Basidiomycetes (and some Ascomycetes) with forest trees.
4. 1 ✘ – in advanced fungi gametes/sex organs are progressively lost (gametangial contact → somatogamy); isogamy → oogamy is the trend of algae/Oomycetes, not of the advanced true fungi.

Short trick: Advanced fungus = septate + dikaryotic + mycorrhizal + somatogamous.

Concept: The question asks for traits that Chlorophyta possess and that set them apart from red algae.

1. 1 ✔ – green algae have chlorophyll a + b (like land plants); red algae have chlorophyll a (+ d) only.
2. 2 ✔ – green algae store true starch inside the plastid around pyrenoids; red algae store floridean starch in the cytoplasm.
3. 3 ✘ – phycobilins (phycoerythrin, phycocyanin) are the hallmark of Rhodophyta, not Chlorophyta.
4. 4 ✘ – absence of motile (flagellate) stages is again a Rhodophyta trait; green algae have flagellate zoospores/gametes.

Short trick: Green: chl a+b, starch in pyrenoid, flagella. Red: phycobilins, floridean starch, no flagella.

Concept: Paraquat (methyl viologen) is a PS I electron diverter.

1. It accepts electrons from the Fe–S centres/ferredoxin on the acceptor side of PS I, so NADP⁺ is not reduced.
2. The reduced paraquat radical gives the electron to O₂ → superoxide → H₂O₂/OH· that destroy membranes (rapid desiccation).
3. DCMU/atrazine/diuron block PS II → plastoquinone (Q_B site); rotenone acts on mitochondrial NADH dehydrogenase–ubiquinone.

Short trick: Paraquat steals at PS I; DCMU blocks at PS II.

Concept: Turner syndrome = 45,XO (monosomy X, 2n − 1) in a phenotypic female.

1. Features: short stature, webbed neck, streak ovaries (sterile), no Barr body.
2. Klinefelter – 47,XXY male; Cri-du-chat – deletion of 5p (structural); Down – trisomy 21 (47,+21).
3. So only Turner has a single X.

Short trick: Turner = 'Ter' (one) X → XO.

Concept: Clements described succession as: nudation → invasion (migration, ecesis, aggregation) → competition & co-action → reaction → stabilization (climax).

1. Nudation – formation of a bare area.
2. Migration – arrival of propagules (seeds, spores).
3. Ecesis – successful germination, establishment of the migrants.
4. Competition – among the established, aggregated individuals for space, light, nutrients.

Short trick: N-M-E-C: Nude land → Move in → Establish → Compete.

Concept: Natural rubber comes from latex of Hevea brasiliensis (Euphorbiaceae).

1. Tapping – a slanting cut in the bark collects latex.
2. Coagulation – latex is diluted and coagulated with dilute formic/acetic acid.
3. Pressing – the coagulum is pressed/rolled into sheets to squeeze out water.
4. Smoking – sheets are dried in a smoke-house (Ribbed Smoked Sheets, RSS).

Short trick: T-C-P-S: Tap → Clot → Press → Smoke.

Concept: Put the milestones in date order.

1. Blakeslee & Avery – colchicine-induced polyploidy in Datura, 1937.
2. Watson & Crick – double-helix model of DNA, 1953.
3. Crick – central dogma (DNA → RNA → protein), 1958 (restated 1970).
4. Hedges & Jacob – coined 'transposon' for the ampicillin-resistance element Tn1, 1974.

Short trick: 1937 → 1953 → 1958 → 1974.

Concept: Archaea live in extremes – halophiles (salt pans), thermoacidophiles (hot springs), methanogens (marshes, rumen).

1. (A) ✔ – they survive due to ether-linked branched lipids (some as monolayers) and stable proteins.
2. (R) ✘ – archaeal walls lack peptidoglycan (murein); they have pseudomurein (N-acetyl-talosaminuronic acid) or protein/glycoprotein S-layers.
3. Peptidoglycan is the wall of eubacteria – that is why archaea resist lysozyme and penicillin.

Short trick: Archaea: ether lipids, no peptidoglycan.

Concept: Apomixis (Winkler, 1908) = substitution of normal sexual reproduction by an asexual process that does not involve meiosis and syngamy.

1. (A) ✔ – gametophytic apomixis (diplospory, apospory) is found mostly in polyploids (e.g. Taraxacum, Rubus, Poa, Citrus); polyploidy and apomixis are strongly associated.
2. (R) ✘ – it states the reverse: apomixis replaces sexual reproduction with an asexual one, not asexual with sexual.

Short trick: Apomixis = seeds without sex (no meiosis, no fertilization).

Concept: Old World = Asia, Africa, Europe; New World = the Americas.

1. a ✔ – Asian rice Oryza sativa was domesticated in China/India (Old World).
2. b ✔ – maize was domesticated from teosinte in Mexico (New World).
3. c ✔ – Vavilov placed bamboo in the Chinese centre of origin.
4. d ✘ – pineapple (Ananas comosus) originated in South America (Brazil–Paraguay) – a New World crop.

Short trick: New World crops: maize, potato, tomato, pineapple, tobacco, rubber, groundnut.

Concept: Match each structure with its role.

1. Nucleosome – 147 bp DNA wrapped 1.65 turns around a histone octamer (a – ii).
2. SAR (scaffold-attachment region)/MAR – AT-rich DNA that anchors chromatin loops to the nuclear matrix/scaffold (b – iv).
3. Tau – a microtubule-associated protein that promotes tubulin assembly and stabilises microtubules (c – i).
4. Dynein-1 (cytoplasmic) – minus-end-directed motor with ATPase activity (d – iii).

Short trick: Nucleosome-147, SAR-scaffold, Tau-tubulin, Dynein-ATPase.

Concept: The Ras superfamily has sub-families with distinct jobs: Ras, Rho, Rab, Arf, Ran.

1. Statement 1 ✔ – Ras relays the RTK signal (RTK → Grb2–SOS → Ras-GTP → Raf → MEK → MAPK/ERK → nucleus) to drive proliferation/differentiation.
2. Statement 2 ✘ – Ran controls nucleo-cytoplasmic transport (importin/exportin cycles, RanGEF in nucleus) and spindle assembly.
3. Vesicle trafficking and exocytosis are regulated by Rab (and Arf/Sar) GTPases.

Short trick: Ras – Signal; Ran – Nuclear transport; Rab – Vesicles.

Concept: Fluid-mosaic membrane (Singer & Nicolson, 1972): lipid bilayer + peripheral and integral proteins.

1. (A) ✔ – the hydrophobic bilayer blocks ions and polar molecules, while integral proteins (channels, carriers, pumps) let only specific solutes through – hence selective permeability.
2. (R) ✘ – integral proteins are highly specific (e.g. aquaporins pass water, K⁺ channels pass K⁺); they do not let every molecule pass freely regardless of size and charge.

Short trick: Integral proteins = gatekeepers, not open doors.