Mock Test 7

Mock Test 07: Advanced Level (75 Questions)

180:00

Evaluation Complete

PART A: General Aptitude

1. What is the missing number in the sequence: 4, 18, ?, 100, 180, 294 A) 32 B) 48 C) 58 D) 64

Ans: B. The pattern is n^3 - n^2. For n=1: 0 (not in series), n=2: 8-4=4, n=3: 27-9=18, n=4: 64-16=48.

2. A sphere is inscribed inside a cube. What is the ratio of the volume of the sphere to the volume of the cube? A) π : 6 B) π : 4 C) 2π : 3 D) 4π : 3

Ans: A. V_sphere = (4/3)πr^3. V_cube = (2r)^3 = 8r^3. Ratio = (4/3)πr^3 / 8r^3 = π/6.

3. A clock loses 5 minutes every hour. If it is set right at 12 Noon, what time will it show at 6 PM on the same day? A) 5:30 PM B) 6:30 PM C) 5:00 PM D) 6:05 PM

Ans: A. In 6 hours, it loses 6 * 5 = 30 minutes. Therefore, it will show 5:30 PM.

4. The sum of two numbers is 25 and their difference is 13. Find their product. A) 104 B) 114 C) 315 D) 325

Ans: B. x+y=25, x-y=13. 2x=38 -> x=19, y=6. Product = 19*6 = 114.

5. If 3 cats catch 3 mice in 3 minutes, how many cats are needed to catch 100 mice in 100 minutes? A) 1 B) 3 C) 33 D) 100

Ans: B. 1 cat catches 1 mouse in 3 minutes. In 100 mins, 1 cat catches 33.3 mice. So 3 cats will catch 100 mice in 100 mins.

6. From a group of 7 men and 6 women, 5 persons are to be selected to form a committee. Probability that at least 3 men are there? A) 756/1287 B) 645/1287 C) 731/1287 D) 645/1287

Ans: A. P(at least 3M) = [C(7,3)*C(6,2) + C(7,4)*C(6,1) + C(7,5)] / C(13,5) = (525 + 210 + 21) / 1287 = 756/1287.

7. In a mixture of 60 liters, the ratio of milk and water is 2:1. How much water must be added to make it 1:2? A) 40 L B) 60 L C) 80 L D) 100 L

Ans: B. Milk = 40L, Water = 20L. We want 40/(20+x) = 1/2 -> 80 = 20+x -> x = 60L.

8. A man walks 10 km towards North. From there he walks 6 km towards South. Then, 3 km towards East. How far and in which direction is he from the start? A) 5 km North-East B) 5 km North-West C) 7 km East D) 7 km West

Ans: A. Net distance N = 4km. East = 3km. Pythagoras: sqrt(4^2+3^2) = 5 km North-East.

9. Find the day of the week on 15th August 1947. A) Wednesday B) Thursday C) Friday D) Saturday

Ans: C. Using calendar odd days calculation for 1947, 15th August falls on a Friday.

10. 12% of a number is 240. What is 25% of that number? A) 400 B) 500 C) 600 D) 800

Ans: B. 0.12x = 240 -> x = 2000. 25% of 2000 is 500.

11. A runs twice as fast as B, and B runs thrice as fast as C. Distance covered by C in 72 mins will be covered by A in: A) 12 mins B) 16 mins C) 18 mins D) 24 mins

Ans: A. V_A = 6*V_C. Therefore, Time_A = Time_C / 6 = 72 / 6 = 12 mins.

12. Find the wrong number in the series: 1, 2, 6, 15, 31, 56, 91 A) 31 B) 56 C) 91 D) 15

Ans: C. Differences: 1, 4, 9, 16, 25, 36. 56 + 36 should be 92, not 91.

13. Pointing to a photograph of a boy, Suresh said, "He is the son of the only son of my mother." How is Suresh related to the boy? A) Brother B) Uncle C) Cousin D) Father

Ans: D. The only son of his mother is Suresh himself. The boy is his son.

14. If '+' means 'minus', '-' means 'multiplied by', '÷' means 'plus', and '×' means 'divided by', then 10 × 5 ÷ 3 - 2 + 3 = ? A) 5 B) 21/5 C) 53/3 D) 18

Ans: A. 10 / 5 + 3 * 2 - 3 = 2 + 6 - 3 = 5.

15. A trader mixes 26 kg of rice at Rs 20/kg with 30 kg of rice at Rs 36/kg and sells it at Rs 30/kg. His profit percent is: A) 5% B) 10% C) 8% D) 12%

Ans: A. Total CP = (26*20) + (30*36) = 1600. Total SP = 56 * 30 = 1680. Profit = 80/1600 = 5%.

16. HCF of 3/16, 5/12, 7/18 is: A) 1/48 B) 1/144 C) 105/144 D) 105/4

Ans: B. HCF of fractions = HCF of numerators / LCM of denominators = 1 / 144.

17. Two pipes A and B can fill a tank in 20 and 30 mins respectively. If both are opened together, how long to fill? A) 10 mins B) 12 mins C) 15 mins D) 25 mins

Ans: B. (20*30)/(20+30) = 600/50 = 12 mins.

18. The difference between CI and SI on an amount of Rs 15,000 for 2 years is Rs 96. What is the rate of interest p.a.? A) 8% B) 10% C) 12% D) 15%

Ans: A. Diff for 2 yrs = P(R/100)^2. 96 = 15000(R^2/10000) => R^2 = 64 => R = 8%.

19. In a group of cows and hens, the number of legs is 14 more than twice the number of heads. How many cows are there? A) 5 B) 7 C) 10 D) 12

Ans: B. Let C = cows, H = hens. 4C + 2H = 2(C + H) + 14. 4C + 2H = 2C + 2H + 14 => 2C = 14 => C = 7.

20. What is the probability of picking a prime number from integers 1 to 20? A) 2/5 B) 7/20 C) 9/20 D) 1/2

Ans: A. Primes: 2, 3, 5, 7, 11, 13, 17, 19 (8 numbers). Prob = 8/20 = 2/5.

21. Find the 10th term of the AP: 3, 7, 11, 15, ... A) 35 B) 39 C) 43 D) 47

Ans: B. a_n = a + (n-1)d = 3 + 9*4 = 39.

22. Out of 100 students, 50 play cricket, 40 play football, and 10 play both. How many play neither? A) 10 B) 20 C) 30 D) 40

Ans: B. n(A U B) = 50 + 40 - 10 = 80. Neither = 100 - 80 = 20.

23. A 60m long train passes a pole in 6 seconds. Its speed in km/hr is: A) 36 B) 48 C) 54 D) 72

Ans: A. Speed = 60/6 = 10 m/s. In km/h = 10 * (18/5) = 36 km/h.

24. What is the value of x if 3^(x+y) = 81 and 81^(x-y) = 3? A) 17/8 B) 15/8 C) 1/8 D) 4

Ans: A. 3^(x+y) = 3^4 => x+y=4. 3^(4(x-y)) = 3^1 => x-y=1/4. 2x = 17/4 => x = 17/8.

25. A bag contains 4 red, 5 green, and 6 blue balls. Probability of drawing a green ball is: A) 1/3 B) 2/5 C) 5/15 D) Both A and C

Ans: D. Total balls = 15. P(Green) = 5/15 = 1/3.

PART B: Core Cell Biology

26. Which type of membrane transport protein undergoes a conformational change driven by ATP hydrolysis to flip specific phospholipids across the bilayer against their gradient? A) Scramblase B) Flippase C) Aquaporin D) Porin

Ans: B. Flippases (P-type ATPases) specifically move lipids towards the cytosolic leaflet.

27. In the N-linked glycosylation of proteins in the ER, the oligosaccharide precursor is transferred from: A) Sphingomyelin B) Farnesyl diphosphate C) Dolichol pyrophosphate D) Phosphatidylinositol

Ans: C. Dolichol is the lipid carrier for the 14-sugar core oligosaccharide.

28. Which vesicular coat protein complex is strictly responsible for retrograde transport from the Golgi apparatus to the ER? A) Clathrin B) COPII C) COPI D) Caveolin

Ans: C. COPI coatomer mediates retrograde transport (Golgi to ER).

29. The Signal Recognition Particle (SRP) binds to the ER signal sequence of a nascent polypeptide. This interaction momentarily halts: A) Transcription B) Translation elongation C) mRNA splicing D) Ribosome assembly

Ans: B. SRP stalls translation until the ribosome docks at the Sec61 translocon.

30. Which cytoskeletal filament has the largest diameter and is organized from a Microtubule Organizing Center (MTOC)? A) Actin filament B) Intermediate filament C) Microtubule D) Myosin thick filament

Ans: C. Microtubules (~25nm) radiate from the centrosome/MTOC.

31. What ion acts as a universal intracellular second messenger to trigger events like muscle contraction, exocytosis, and apoptosis? A) Na+ B) K+ C) Mg2+ D) Ca2+

Ans: D. Calcium ions (Ca2+) are critical second messengers in numerous pathways.

32. The nuclear lamina provides structural support to the nuclear envelope. It is composed of lamins, which are classified as: A) Microtubules B) Actin-binding proteins C) Intermediate filaments D) Septins

Ans: C. Nuclear lamins are Type V intermediate filaments.

33. Which phase of the cell cycle is targeted by the drug Taxol, which stabilizes microtubules and prevents spindle disassembly? A) G1 phase B) S phase C) Mitosis (M phase) D) Cytokinesis

Ans: C. Taxol arrests cells in metaphase by preventing microtubule depolymerization.

34. A G-protein-coupled receptor (GPCR) functions as a Guanine Nucleotide Exchange Factor (GEF) for the G-alpha subunit. Upon activation, G-alpha: A) Exchanges GDP for GTP and dissociates from G-beta-gamma B) Hydrolyzes GTP to GDP C) Binds beta-arrestin D) Is ubiquitinated

Ans: A. Ligand binding causes the GPCR to promote GDP release and GTP binding on G-alpha, activating it.

35. Which organelle is highly enriched in catalase and is primarily responsible for breaking down very long-chain fatty acids? A) Lysosome B) Mitochondrion C) Peroxisome D) Smooth ER

Ans: C. Peroxisomes handle VLCFA beta-oxidation and use catalase to detoxify H2O2.

36. Cadherins mediate cell-cell adhesion primarily in adherens junctions and desmosomes. Their binding is strictly dependent on: A) Magnesium ions B) Calcium ions C) ATP D) Fibronectin

Ans: B. Cadherins (Calcium-dependent adhesion molecules) require Ca2+ for their rigid extracellular conformation.

37. In mitochondria, ATP synthase is located in the inner membrane. The energy driving the rotation of its F0 rotor comes directly from: A) Electron transport B) The flow of protons down their electrochemical gradient C) NADH oxidation D) GTP hydrolysis

Ans: B. The proton motive force (PMF) drives protons back into the matrix through the F0 complex, turning the rotor.

38. Which cell cycle checkpoint ensures that all chromosomes are properly attached to the bipolar spindle before allowing sister chromatid separation? A) G1/S checkpoint B) G2/M checkpoint C) Spindle Assembly Checkpoint (SAC) D) DNA damage checkpoint

Ans: C. The SAC (M-checkpoint) prevents APC/C activation until kinetochores are fully attached.

39. Extracellular matrix (ECM) proteins, such as collagen and laminin, interact with the actin cytoskeleton through transmembrane receptors known as: A) Selectins B) Integrins C) Claudins D) Connexins

Ans: B. Integrins physically link ECM components to the intracellular cytoskeleton at focal adhesions.

40. Apoptosis execution relies on a cascade of proteases that cleave specific substrates. These enzymes are known as: A) Cathepsins B) Matrix metalloproteinases C) Caspases D) Calpains

Ans: C. Caspases (Cysteine-dependent Aspartate-directed Proteases) execute programmed cell death.

41. The primary protein forming the contractile ring during cytokinesis in animal cells is: A) Microtubules and Dynein B) Actin and Myosin II C) Keratin and Desmin D) Clathrin

Ans: B. An actomyosin contractile ring pinches the cell in two during cytokinesis.

42. Gap junctions are communicating junctions that allow the passage of small ions and water-soluble molecules. Their structural pore is formed by: A) Porins B) Connexons C) Plasmodesmata D) Aquaporins

Ans: B. Connexons (made of 6 connexins) align to form gap junctions.

43. Retinoblastoma (Rb) protein prevents cell cycle progression from G1 to S phase by binding and sequestering which transcription factor? A) p53 B) Myc C) E2F D) AP-1

Ans: C. Rb traps E2F. Phosphorylation of Rb by G1-Cdks releases E2F to transcribe S-phase genes.

44. I-cell disease is a severe lysosomal storage disorder. It is caused by a defect in tagging lysosomal enzymes with: A) KDEL B) Mannose-6-phosphate C) Ubiquitin D) GPI anchors

Ans: B. Without the M6P tag (due to a phosphotransferase defect), enzymes are secreted rather than delivered to lysosomes.

45. During protein import into the nucleus, the transport receptor (Importin) releases its cargo when it binds to: A) Ran-GDP B) Ran-GTP C) Nuclear pore proteins D) DNA

Ans: B. High concentration of Ran-GTP in the nucleus binds importin, inducing a conformational change that drops the cargo.

46. The oncogenic Ras protein is usually locked in its active state due to mutations that destroy its: A) GTP-binding affinity B) Membrane anchoring C) Intrinsic GTPase activity D) Kinase domain

Ans: C. Mutations like G12V prevent Ras from hydrolyzing GTP to GDP, keeping it perpetually active.

47. Which secondary messenger is responsible for releasing calcium from the smooth endoplasmic reticulum? A) cAMP B) cGMP C) Diacylglycerol (DAG) D) Inositol 1,4,5-trisphosphate (IP3)

Ans: D. IP3 binds to IP3-gated calcium channels on the ER, releasing stored Ca2+.

48. Proteasomal degradation of proteins requires prior covalent attachment of a polyubiquitin chain. This chain is typically linked via which lysine residue on ubiquitin? A) K11 B) K48 C) K63 D) K29

Ans: B. K48-linked polyubiquitination is the canonical signal for 26S proteasome degradation.

49. Autophagy requires the formation of a double-membrane autophagosome. A key protein lipidated to the autophagosome membrane (and used as an experimental marker) is: A) p62 B) LC3-II C) Beclin-1 D) mTOR

Ans: B. LC3 is cleaved and lipidated to phosphatidylethanolamine to form LC3-II on the autophagosome membrane.

50. Which antibiotic structurally mimics aminoacyl-tRNA, enters the A site of the ribosome, and causes premature termination of translation? A) Tetracycline B) Chloramphenicol C) Puromycin D) Streptomycin

Ans: C. Puromycin is incorporated into the nascent peptide chain, terminating translation.

PART C: Advanced / Experimental Cell Biology

51. In a FRAP experiment evaluating a membrane protein, a plateau of 50% recovery is achieved. If the actin cytoskeleton is completely disrupted by Latrunculin A, the recovery plateaus at 95%. This suggests: A) The protein is an actin monomer. B) 50% of the protein is normally tethered to the cortical actin cytoskeleton. C) The protein undergoes rapid endocytosis. D) The lipid bilayer is solid.

Ans: B. Depolymerizing actin releases the tethered fraction, allowing near-total free diffusion (95% mobile fraction).

52. During the Unfolded Protein Response (UPR), the PERK kinase specifically phosphorylates eIF2-alpha. The direct physiological consequence of this is: A) Massive upregulation of global translation B) Immediate apoptosis C) Global attenuation of translation, with selective translation of ATF4/ATF4-like mRNAs D) Proteasome inhibition

Ans: C. Phosphorylation of eIF2-alpha halts general protein synthesis to reduce ER load but allows translation of specific stress-response mRNAs.

53. In Notch signaling, the Presenilin protein is the catalytic core of the gamma-secretase complex. Mutations in Presenilin are primarily linked to early-onset: A) Parkinson's Disease B) Alzheimer's Disease C) Huntington's Disease D) Retinoblastoma

Ans: B. Gamma-secretase also cleaves Amyloid Precursor Protein (APP). Presenilin mutations alter this cleavage, increasing toxic A-beta 42 aggregates.

54. Surface Plasmon Resonance (SPR) is used to study protein-protein interactions. If Protein A is immobilized on the sensor chip and Protein B is flowed over it, an increase in Resonance Units (RU) directly correlates to: A) The dissociation rate (koff) B) The mass of the accumulating complex on the sensor surface C) The fluorescence intensity of Protein B D) Heat generation

Ans: B. SPR measures changes in the refractive index near the sensor surface, which is directly proportional to mass accumulation.

55. Tumor cells exhibiting the Warburg effect predominantly express the PKM2 splice variant. Unlike PKM1, PKM2 can be allosterically activated by: A) Fructose-1,6-bisphosphate (FBP) B) ATP C) Citrate D) Acetyl-CoA

Ans: A. FBP acts as a feed-forward allosteric activator to temporarily force the low-activity dimeric PKM2 into a highly active tetrameric state.

56. The tumor suppressor PTEN antagonizes the PI3K pathway. A loss-of-function mutation in PTEN will directly lead to the constitutive hyperactivation of: A) GSK-3 B) Akt (Protein Kinase B) C) Smad4 D) Caspase-9

Ans: B. Without PTEN to dephosphorylate PIP3, PIP3 accumulates at the membrane, recruiting and constitutively activating Akt.

57. During the assembly of the clathrin coat, the GTPase Dynamin is responsible for vesicle scission. A temperature-sensitive mutation in Drosophila dynamin (shibire) at restrictive temperatures causes: A) Failure of vesicles to fuse with endosomes B) Accumulation of deeply invaginated, coated pits that fail to pinch off C) Instant vesicle uncoating D) Lack of clathrin triskelion formation

Ans: B. Without functional dynamin to constrict the neck, endocytosis halts at the deeply invaginated pit stage, leading to rapid paralysis in flies.

58. The anaphase-promoting complex (APC/C) requires the co-activator Cdc20 to trigger anaphase. The Spindle Assembly Checkpoint (SAC) inhibits APC/C-Cdc20 by sequestering Cdc20 using the: A) Securin complex B) Mitotic Checkpoint Complex (MCC), predominantly Mad2 C) Cohesin ring D) Aurora B kinase

Ans: B. Unattached kinetochores generate the MCC (Mad2, BubR1, Bub3) which binds and inhibits Cdc20.

59. In canonical Wnt signaling, the stabilization of beta-catenin requires the inhibition of the 'destruction complex'. The key scaffolding protein in this complex that is often mutated in colon cancers is: A) GSK-3 B) Dishevelled C) APC (Adenomatous Polyposis Coli) D) TCF/LEF

Ans: C. APC provides the scaffold for Axin, GSK3, and beta-catenin. Truncating mutations in APC disrupt the complex, causing constitutive beta-catenin activation.

60. FRET efficiency is inversely proportional to the 6th power of the distance between fluorophores (1/r^6). Which condition is NOT required for successful FRET? A) Distance between 1-10 nm B) Overlap between donor emission and acceptor excitation spectra C) Favorable dipole-dipole orientation D) Both fluorophores must be covalently linked to the exact same protein

Ans: D. FRET measures proximity. Fluorophores can be on separate interacting proteins (intermolecular FRET).

61. In the context of RTK signaling, Grb2 is a classic adaptor protein. Its structural configuration consists of: A) One SH2 domain and two SH3 domains B) A Kinase domain and a PH domain C) Two SH2 domains D) A Death Domain (DD) and a DED

Ans: A. The SH2 domain binds phosphotyrosines on the RTK, while the SH3 domains bind proline-rich regions on SOS (the Ras GEF).

62. Which of the following drugs acts by specifically inhibiting the V-type ATPase, thereby neutralizing the pH of lysosomes and endosomes? A) Brefeldin A B) Bafilomycin A1 C) Nocodazole D) Cytochalasin D

Ans: B. Bafilomycin A1 is a highly specific inhibitor of V-ATPases, rapidly collapsing organelle acidification.

63. In mammalian cells, macroautophagy utilizes a ubiquitin-like conjugation system to lipidate LC3. The E1-like activating enzyme in this system is: A) ATG5 B) ATG7 C) ATG12 D) ATG7

Ans: D. ATG7 acts as the E1-like enzyme for both the ATG12-ATG5 conjugation and the LC3-PE lipidation pathways.

64. Optogenetics employs light-sensitive ion channels. Channelrhodopsin-2 (ChR2), when illuminated with blue light, primarily functions as a: A) Chloride pump causing hyperpolarization B) Proton pump C) Non-specific cation channel causing depolarization D) Light-gated GPCR

Ans: C. ChR2 permits Na+ and Ca2+ influx, depolarizing the cell membrane (used to activate neurons).

65. The "kiss of death" for a protein is a polyubiquitin chain linked via Lysine 48 (K48). Conversely, polyubiquitination linked via Lysine 63 (K63) predominantly functions in: A) Proteasomal degradation B) DNA repair and signaling scaffolding C) Exporting proteins from the nucleus D) Targeting to the peroxisome

Ans: B. K63-linked chains alter protein function, localization, and assemble signaling complexes rather than promoting degradation.

66. A researcher discovers a mutant cell line that arrests in G2. The mutation is mapped to a protein that is normally heavily phosphorylated. When the researcher transfects a constitutively active Cdc25 phosphatase, the cells bypass the arrest. The original mutation likely hyperactivates: A) Cyclin B B) Wee1 kinase C) APC/C D) Separase

Ans: B. Wee1 puts the inhibitory phosphate on M-Cdk. Hyperactive Wee1 locks cells in G2. Cdc25 removes this phosphate, overriding the Wee1 block.

67. The phenomenon of "Treadmilling" in actin filaments occurs precisely at the critical concentration where: A) Both ends are shrinking B) The rate of addition at the barbed (+) end exactly matches the rate of dissociation at the pointed (-) end C) ATP hydrolysis ceases D) Severing proteins cut the filament in half

Ans: B. At steady state treadmilling, the net length remains constant while monomers flux through the filament.

68. Imatinib (Gleevec) revolutionized cancer therapy. It acts as a competitive inhibitor of the ATP-binding pocket of which oncogenic tyrosine kinase? A) BRAF V600E B) EGFR C) BCR-ABL D) HER2/neu

Ans: C. Imatinib specifically targets the BCR-ABL fusion protein characteristic of Chronic Myeloid Leukemia (CML).

69. Necroptosis is a highly regulated necrotic cell death pathway characterized by plasma membrane rupture. The actual pore-forming executioner protein of necroptosis is: A) Caspase-1 B) RIPK1 C) MLKL D) Gasdermin D

Ans: C. Phosphorylated MLKL oligomerizes and disrupts the plasma membrane. (Gasdermin D executes pyroptosis).

70. Which class of molecular motors utilizes a "hand-over-hand" walking mechanism along microtubules, specifically requiring the leading head to bind tightly upon ATP binding? A) Dynein B) Kinesin-1 C) Myosin V D) Dynamin

Ans: B. ATP binding to the leading head of kinesin induces neck-linker zippering, throwing the trailing head forward.

71. In CRISPR-Cas9 genome editing, Homology-Directed Repair (HDR) is preferred over Non-Homologous End Joining (NHEJ) when the goal is to: A) Create a simple gene knockout B) Induce random frameshift mutations C) Insert a specific sequence or correct a point mutation D) Delete large chromosomal segments

Ans: C. HDR utilizes a provided repair template to achieve precise "knock-in" sequence edits.

72. Extrinsic apoptosis involves Death Receptors (e.g. Fas) recruiting FADD. What specific protein-protein interaction domain binds the Fas receptor to the FADD adaptor? A) DED (Death Effector Domain) B) DD (Death Domain) C) CARD D) BIR domain

Ans: B. Homotypic DD-DD interactions link Fas to FADD. FADD then uses its DED to recruit Procaspase-8.

73. A cell undergoing EMT (Epithelial-Mesenchymal Transition) will typically downregulate which critical cell-adhesion molecule to gain motility? A) N-cadherin B) Vimentin C) E-cadherin D) Fibronectin

Ans: C. Loss of E-cadherin breaks epithelial adherens junctions, a hallmark of EMT. (They often switch to expressing N-cadherin).

74. In cell cycle analysis via flow cytometry using Propidium Iodide (PI), a distinct peak with exactly twice the fluorescence intensity of the G1 peak represents cells in: A) Early S phase B) G0 phase C) G2 and M phases D) Apoptosis (Sub-G1)

Ans: C. Cells in G2/M have 4n DNA content, absorbing twice as much PI dye as the 2n G1 cells.

75. The sec-dependent transport of unfolded proteins across membranes requires a pushing/pulling motor. In the ER, this function is provided by: A) SecA B) BiP (an Hsp70 chaperone) and ATP hydrolysis C) A proton gradient D) SRP GTPase

Ans: B. BiP binds incoming polypeptides on the luminal side and uses an ATP-dependent ratcheting mechanism to pull them through the Sec61 pore.