UPHESC Assistant Professor Zoology 2025 PYQs

Concept: The Na⁺/K⁺-ATPase is a P-type primary active transporter that uses one ATP per cycle.

1. It pumps 3 Na⁺ OUT of the cell and 2 K⁺ IN.
2. This keeps Na⁺ high outside and K⁺ high inside and makes the pump electrogenic (net one + charge out).
3. Options A–C reverse the direction or the numbers (and K is a cation, not K^–).

Short trick: "3 Out, 2 In" – Sodium leaves, Potassium enters (SO-PI).

Concept: The nucleosome core particle is a histone octamer – two copies each of H2A, H2B, H3 and H4 – wrapped by ~146–147 bp DNA (1.65 turns).

1. H3–H4 form a tetramer; two H2A–H2B dimers join it.
2. H1 is the linker histone, outside the core (seals DNA entry/exit), so B and D are wrong.
3. There is no separate "H2" histone in the core, so A is wrong.

Short trick: Core = "2A-2B-3-4, two of each = 8"; H1 sits outside.

Concept: India's first biosphere reserve was the Nilgiri Biosphere Reserve (1986), spread over Tamil Nadu, Kerala and Karnataka.

1. Nanda Devi – 1988.
2. Nokrek – 1988.
3. Gulf of Mannar – 1989.

Short trick: "N-N-N-G": Nilgiri (86) → Nanda Devi, Nokrek (88) → Gulf of Mannar (89).

Concept: Among animals, bats (order Chiroptera) are the classic producers of ultrasonic sound; Pteropus (flying fox) is the only bat in the list.

1. Ultrasonic echolocation is best developed in insect-eating microbats; fruit bats such as Pteropus rely mostly on vision and smell, but textbooks list 'bats (Pteropus)' as the ultrasound producer.
2. Gorilla, bear and emu make only audible sounds (the emu's booming is low-frequency).
3. So (D) is the only option that fits.

Short trick: Ultrasound in animals → think "bats & dolphins"; Pteropus = flying fox (bat).

Concept: Positive interactions: at least one partner gains and none is harmed (+,+ or +,0).

1. Mutualism (+,+, obligatory), protocooperation (+,+, non-obligatory), commensalism (+,0) – all positive.
2. Amensalism (–,0): one species is inhibited, the other unaffected (e.g. Penicillium antibiotic on bacteria) – a negative interaction.

Short trick: "A-mensalism = A-gainst" – the only one with a minus sign.

Concept: The pygmy hog (Porcula salvania), the world's smallest wild pig, survives only in a few grasslands of Assam (Manas). It was assessed Critically Endangered by IUCN for many years; after captive breeding and reintroduction its latest IUCN assessment is Endangered, but it is still the most threatened of the four and the standard textbook answer.

1. Red panda – Endangered.
2. Blackbuck – Least Concern (IUCN), though Schedule I in India.
3. Leopard – Vulnerable.

Short trick: "Pygmy = tiny numbers" – smallest pig, highest threat category among these.

Concept: Parametric tests assume a distribution (usually normal) and use parameters such as mean and variance.

1. ANOVA (F-test) compares means of 3+ groups – parametric.
2. Kruskal-Wallis (non-parametric ANOVA), Mann-Whitney U (non-parametric t-test) and Spearman's rank correlation work on ranks – non-parametric.

Short trick: If the test uses "ranks" or a person's name pair (Kruskal-Wallis, Mann-Whitney, Spearman) → non-parametric; t, F (ANOVA), Pearson r → parametric.

Concept: X-rays are ionizing radiation; they break the sugar-phosphate backbone (single- and double-strand breaks).

1. Mis-repair of breaks gives deletions and chromosomal aberrations (deletions, translocations, inversions) – the typical X-ray lesion.
2. Transitions/transversions (base substitutions) are typical of chemical mutagens (base analogues, alkylating agents, nitrous acid).
3. UV, by contrast, causes thymine dimers.

Short trick: "X-ray = X out (break & delete)"; UV = dimers; chemicals = substitutions.

Concept: Under ICZN/ICN, scientific names must be in Latin or Latinised form – not in any language.

1. First word = genus (capital initial), second = specific epithet (small letter) – a rule.
2. Printed names are italicised; handwritten names are underlined (separately for genus and species) – rules.
3. So "names can be written in any language" is contrary to the rules.

Short trick: Scientific names are "Latin-only" – one universal language for one universal name.

Concept: Blind-sac plan = gut with a single opening (mouth also acts as anus) – seen in Cnidaria, Ctenophora and Platyhelminthes.

1. A – false: flatworms are at organ-system level but have a blind-sac (not tube-within-tube) plan.
2. B – false: flatworms are blind-sac yet triploblastic.
3. C – true: radially symmetrical cnidarians and ctenophores have a blind-sac gastrovascular cavity.
4. D – reversed: all vertebrates are chordates, not all chordates are vertebrates.

Short trick: Radial (Cnidaria, Ctenophora) → one opening → blind sac.

Concept: Lungfishes (Dipnoi) share several primitive features with elasmobranchs but are bony fishes with an operculum.

1. Shared with cartilaginous fishes: spiral valve in intestine, a conus arteriosus, absence of nephrostomes in the adult kidney.
2. Gills covered by an operculum is an osteichthyan feature; sharks/rays have naked gill slits.

Short trick: "Shark = 5–7 open slits, no lid"; operculum = bony-fish lid.

Concept: Erwin Chargaff (1950) found that in double-stranded DNA A = T and G = C, so purines = pyrimidines (A+G = T+C).

1. This later supported Watson–Crick base pairing.
2. Van't Hoff plot (thermodynamics), Coulomb's law (electrostatics) and Le Chatelier's principle (equilibrium) are unrelated.

Short trick: "Chargaff = Charge-equal pairs: A=T, G≡C".

Concept: Hydrophobicity comes from long non-polar hydrocarbon (alkyl) chains of fatty acids.

1. C–H bonds are non-polar, cannot form H-bonds with water.
2. Hydroxyl, carbonyl and phosphate groups are polar/charged – they make the hydrophilic "head" of amphipathic lipids.

Short trick: Tail = alkyl = water-hating; head = phosphate/OH = water-loving.

Concept: The glycocalyx ("sugar coat") is the carbohydrate-rich layer on the outer surface of the plasma membrane.

1. It is formed by oligosaccharide chains of glycoproteins and glycolipids plus proteoglycans.
2. Glycans, glycoproteins and proteoglycans are its components, not the name of the zone.
3. Functions: cell recognition, adhesion, protection (e.g. intestinal microvilli).

Short trick: Glyco = sugar, calyx = cup/coat → sugar coat.

Concept: Cenozoic epochs, oldest to youngest: Palaeocene → Eocene → Oligocene → Miocene → Pliocene → Pleistocene → Holocene.

1. Palaeocene (I) 66–56 Ma, Eocene (II) 56–34 Ma, Oligocene (IV) 34–23 Ma.
2. Pleistocene (III) 2.6 Ma–11,700 yr is the youngest of the four.
3. Order = I, II, IV, III.

Short trick: "Put Eggs On My Plate Please Honey" – Palaeo, Eo, Oligo, Mio, Plio, Pleisto, Holo.

Concept: The obturator foramen is the large opening in each hip bone (os innominatum), bounded by the pubis and ischium.

1. It lies just below the acetabulum; the obturator nerve and vessels pass through it.
2. Heart has foramen ovale (foetal); vertebrae have the vertebral foramen; the pectoral girdle has no obturator foramen.

Short trick: Obturator = "between pubis and ischium" → pelvis.

Concept: Match each term to its function/association.

1. Mons pubis – fatty pad over the pubic symphysis, part of the vulva → female external genitalia (iii).
2. Glomerulus – ultrafiltration, first step of urine formation (i).
3. Ferroptosis – iron-dependent, lipid-peroxidation cell death; iron links it to haemoglobin/haem (iv).
4. Protein hormones cannot enter cells; they act through second messengers such as cAMP (ii).

Short trick: Ferr- = iron → haemoglobin; protein hormone → stays outside → needs a messenger.

Concept: Hominin sequence (oldest → youngest): Australopithecus → Homo habilis → Homo erectus → Homo sapiens.

1. Australopithecus (II) ~4–2 Ma, bipedal ape-man.
2. Homo habilis (III) ~2.4–1.4 Ma, "handy man", first stone tools.
3. Homo erectus (IV) ~1.9 Ma–110 ka, used fire.
4. Homo sapiens (I) ~300 ka to present. Order: II, III, IV, I.

Short trick: "A-H-E-S": Ape-man → Handy → Erect → Sapiens (wise).

Concept: Kin selection (W. D. Hamilton, 1964) explains altruism by inclusive fitness: helping relatives spreads shared genes.

1. Hamilton's rule: altruism is favoured when $rB>C$ (r = coefficient of relatedness, B = benefit to recipient, C = cost to altruist).
2. Example: sterile worker bees (r = 0.75 with sisters in haplodiploidy).
3. Reciprocal benefit is "reciprocal altruism" (Trivers), a different mechanism.

Short trick: "Kin = Genes in common" → $rB>C$.

Concept: Know the molecular target of common drugs/toxins.

1. Cyclosporin-A binds cyclophilin and inhibits calcineurin, a protein phosphatase (the "phosphate inhibitor" of the list) → a–III.
2. Rapamycin (with FKBP12) inhibits the kinase mTOR → b–II.
3. A rise in cAMP activates PKA, which acts by phosphorylation → c–IV.
4. Ouabain blocks the Na⁺/K⁺ pump that moves K⁺ into the cell → d–I.

Short trick: CsA → Calcineurin (phosphatase); Rapa → mTOR (kinase); Ouabain → Na/K pump.