Mock Test 5

Mock Test 05: CSIR-NET Pattern (Part A & Part C)

180:00

PART A: General Aptitude (Questions 1 - 30)

1. What is the next number in the series: 2, 6, 12, 20, 30, ...? A) 40 B) 42 C) 44 D) 48

Ans: B. The pattern is n^2 + n. For n=6: 36+6 = 42.

2. A train 150m long is running at 72 km/h. How long will it take to cross a 250m long bridge? A) 10s B) 15s C) 20s D) 25s

Ans: C. Speed = 72 * (5/18) = 20 m/s. Total distance = 150+250 = 400m. Time = 400/20 = 20s.

3. Pointing to a photograph, a man said, "I have no brother or sister but that man's father is my father's son." Whose photograph was it? A) His own B) His son's C) His father's D) His nephew's

Ans: B. "My father's son" is the man himself. So, the man in the photo's father is the speaker. Hence, it's his son's photograph.

4. The sum of the ages of 5 children born at the intervals of 3 years each is 50 years. What is the age of the youngest child? A) 4 years B) 8 years C) 10 years D) None of the above

Ans: A. x + (x+3) + (x+6) + (x+9) + (x+12) = 50. 5x + 30 = 50. x = 4.

5. If A is the brother of B; B is the sister of C; and C is the father of D, how D is related to A? A) Brother B) Sister C) Nephew D) Cannot be determined

Ans: D. D's gender is unknown, so D could be a nephew or niece.

6. A sphere and a cylinder have the same radius and same volume. The ratio of the radius to the height of the cylinder is: A) 1:2 B) 2:1 C) 3:4 D) 4:3

Ans: C. (4/3)πr^3 = πr^2h => (4/3)r = h => r/h = 3/4.

7. In a certain code language, "COMPUTER" is written as "RFUVQNPC". How will "MEDICINE" be written in that code? A) EOJDJEFM B) EOJDEJFM C) MFEJDJOE D) MFEDJJOE

Ans: A. The letters are reversed, and the first and last remain unchanged, while others shift by +1.

8. A can do a piece of work in 8 days and B can do it in 12 days. They work together for 3 days. What fraction of work is left? A) 3/8 B) 5/8 C) 1/2 D) 1/4

Ans: A. Work done in 1 day = 1/8 + 1/12 = 5/24. In 3 days = 15/24 = 5/8. Left = 1 - 5/8 = 3/8.

9. Two dice are thrown simultaneously. What is the probability of getting a sum of 9? A) 1/9 B) 1/12 C) 1/6 D) 1/36

Ans: A. Favorable outcomes: (3,6), (4,5), (5,4), (6,3). Total 4. Prob = 4/36 = 1/9.

10. 100 students appeared for an exam. 60 passed in Math, 50 in Science, and 20 passed in both. How many failed in both? A) 10 B) 20 C) 30 D) 0

Ans: A. Passed in at least one = 60 + 50 - 20 = 90. Failed in both = 100 - 90 = 10.

11. Find the missing number: 3, 7, 15, 31, 63, ? A) 92 B) 115 C) 127 D) 131

Ans: C. Pattern: x2 + 1. 63 * 2 + 1 = 127.

12. A clock is started at noon. By 10 minutes past 5, the hour hand has turned through: A) 145 deg B) 150 deg C) 155 deg D) 160 deg

Ans: C. Hour hand turns 0.5 deg per minute. 5 hrs 10 mins = 310 mins. 310 * 0.5 = 155 deg.

13. In a 100m race, A covers the distance in 36 sec and B in 45 sec. In this race, A beats B by: A) 20m B) 25m C) 22.5m D) 9m

Ans: A. A finishes in 36s. In 36s, B covers (100/45)*36 = 80m. A beats B by 20m.

14. If log 2 = 0.3010, the value of log 25 is: A) 1.3980 B) 1.5050 C) 1.6020 D) 1.2040

Ans: A. log 25 = log(100/4) = log 100 - 2 log 2 = 2 - 2(0.3010) = 1.3980.

15. A vendor bought toffees at 6 for a rupee. How many for a rupee must he sell to gain 20%? A) 3 B) 4 C) 5 D) 6

Ans: C. Cost of 6 is Rs 1. SP of 6 = 1.20 Rs. So, for Rs 1, he must sell 6/1.2 = 5 toffees.

16. The probability of a leap year containing 53 Sundays is: A) 1/7 B) 2/7 C) 53/366 D) 3/7

Ans: B. 366 days = 52 weeks + 2 days. The 2 days can be Sun-Mon, Sat-Sun, etc. 2 out of 7 combinations contain a Sunday.

17. A hemispherical bowl of radius r is completely filled with liquid. The liquid is poured into a cylindrical glass of radius r. The height of the liquid in the glass will be: A) r B) (2/3)r C) (4/3)r D) 2r

Ans: B. (2/3)πr^3 = πr^2h => h = (2/3)r.

18. Out of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed? A) 210 B) 1050 C) 25200 D) 21400

Ans: C. Ways to choose = 7C3 * 4C2 = 35 * 6 = 210. Ways to arrange the 5 letters = 210 * 5! = 25200.

19. If the price of an item is increased by 25%, by what percent must consumption be reduced to keep expenditure constant? A) 20% B) 25% C) 30% D) 15%

Ans: A. Reduction = [r / (100+r)] * 100 = [25/125] * 100 = 20%.

20. Look at this series: 7, 10, 8, 11, 9, 12, ... What number should come next? A) 7 B) 10 C) 12 D) 13

Ans: B. Pattern is +3, -2. So, 12 - 2 = 10.

21. What is the angle between the hands of a clock at 3:15? A) 0 deg B) 7.5 deg C) 15 deg D) 3 deg

Ans: B. Angle = |30H - 5.5M| = |90 - 82.5| = 7.5 degrees.

22. The HCF of two numbers is 11 and their LCM is 7700. If one number is 275, the other is: A) 279 B) 283 C) 308 D) 318

Ans: C. Product of numbers = HCF * LCM. (11 * 7700) / 275 = 308.

23. Water flows into a tank at 20 liters/minute. If the tank is full in 2.5 hours, what is its capacity? A) 3000 L B) 5000 L C) 1200 L D) 2500 L

Ans: A. 2.5 hours = 150 minutes. 150 * 20 = 3000 liters.

24. Find the simple interest on Rs 5200 for 2 years at 6% per annum. A) Rs 624 B) Rs 600 C) Rs 724 D) Rs 524

Ans: A. SI = (P*R*T)/100 = (5200*6*2)/100 = 624.

25. A boat travels 24 km upstream in 6 hours and 20 km downstream in 4 hours. Find the speed of the boat in still water. A) 4.5 km/h B) 4 km/h C) 5 km/h D) 5.5 km/h

Ans: A. Upstream = 4 km/h. Downstream = 5 km/h. Speed = (5+4)/2 = 4.5 km/h.

26. Which of the following fractions is the largest? A) 7/8 B) 13/16 C) 31/40 D) 63/80

Ans: A. 7/8 = 0.875, which is the largest among the options.

27. If 5 machines can make 5 widgets in 5 minutes, how long will it take 100 machines to make 100 widgets? A) 100 minutes B) 5 minutes C) 50 minutes D) 10 minutes

Ans: B. 1 machine makes 1 widget in 5 minutes. 100 machines make 100 widgets in 5 minutes.

28. A man buys a watch for Rs 1950 in cash and sells it for Rs 2200 at a credit of 1 year. If the interest rate is 10% per annum, the man: A) Gains Rs 50 B) Loses Rs 50 C) Gains Rs 250 D) Loses Rs 30

Ans: A. Present worth of 2200 due 1 yr later at 10% = 2200/1.1 = 2000. Gain = 2000 - 1950 = 50.

29. The perimeter of a rectangle is 82m and its area is 400m^2. What is its breadth? A) 25m B) 16m C) 9m D) 20m

Ans: B. L+B = 41. LB = 400. Factors of 400 that sum to 41 are 25 and 16. Breadth is 16m.

30. Find the odd one out: 8, 27, 64, 100, 125, 216, 343. A) 27 B) 100 C) 125 D) 343

Ans: B. 100 is a square, while all others are perfect cubes (2^3, 3^3, etc).

PART C: Advanced Life Sciences (Questions 31 - 60)

31. A researcher treats a plant callus culture with silver nanoparticles (AgNPs) to observe changes in secondary metabolite profiles. This technique utilizes AgNPs primarily as: A) Carbon sources B) Abiotic elicitors C) Cryoprotectants D) DNA intercalators

Ans: B. Nanoparticles act as abiotic elicitors by generating ROS, triggering defense responses that ramp up secondary metabolite (e.g., alkaloid) production.

32. In a Ramachandran plot, a highly constrained peptide sequence showing phi (Φ) angles around -60° and psi (Ψ) angles around -45° predominantly forms: A) Antiparallel beta-sheets B) Left-handed alpha-helices C) Right-handed alpha-helices D) Collagen triple helices

Ans: C. Right-handed alpha-helices occupy the lower-left quadrant of the Ramachandran plot.

33. Tunicamycin blocks N-linked glycosylation. Treating mammalian cells with tunicamycin will rapidly lead to the accumulation of unfolded proteins in the ER, activating: A) The Unfolded Protein Response (UPR) via IRE1, PERK, and ATF6 B) Nuclear import of exportins C) Rapid vesicle exocytosis D) Activation of the spindle assembly checkpoint

Ans: A. ER stress from misfolded glycoproteins triggers the UPR to restore homeostasis or induce apoptosis.

34. A double-mutant lac operon has a non-functional repressor (I-) and a mutation in the operator (Oc) preventing any repressor binding. The expression phenotype will be: A) Uninducible B) Inducible, normal regulation C) Constitutive expression D) Lethal

Ans: C. Both defects prevent repression, leading to continuous (constitutive) transcription of the lac operon.

35. During a molecular docking simulation of a novel ligand binding to a plant receptor kinase, the most negative docking score (e.g., -9.8 kcal/mol) generally indicates: A) The weakest binding affinity B) The most thermodynamically favorable binding pose C) Immediate covalent bond formation D) Steric clashes preventing binding

Ans: B. A more negative Delta G signifies a more spontaneous and stable ligand-receptor complex.

36. While running an SDS-PAGE, beta-mercaptoethanol is added to the loading buffer. Its primary purpose is to: A) Provide a uniform negative charge to the protein B) Act as a tracking dye C) Reduce disulfide bonds, fully linearizing the polypeptide D) Increase the density of the sample

Ans: C. It acts as a reducing agent, breaking intrinsic and extrinsic disulfide bridges.

37. In C4 photosynthesis, the spatial separation of initial CO2 fixation and the Calvin cycle occurs between the mesophyll cells and the: A) Epidermal cells B) Bundle sheath cells C) Guard cells D) Phloem sieve tubes

Ans: B. C4 plants use Kranz anatomy, separating PEP-mediated fixation (mesophyll) from RuBisCO activity (bundle sheath).

38. In a dihybrid cross of two heterozygous individuals (AaBb x AaBb) exhibiting dominant epistasis (12:3:1 ratio), which genotype represents the "1" phenotype? A) AABB B) Aabb C) aaBB D) aabb

Ans: D. The double recessive (aabb) displays the masked "1" phenotype in a 12:3:1 epistatic ratio.

39. A mutant yeast strain arrests in G2-phase. The mutation is most likely an inactivating mutation in: A) Cdc25 phosphatase B) Wee1 kinase C) APC/C D) Sic1

Ans: A. Cdc25 removes the inhibitory phosphate placed by Wee1. If Cdc25 is inactive, M-Cdk remains inhibited, causing a G2 arrest.

40. In GPCR signaling, which domain of the alpha subunit acts as an intrinsic GTPase to terminate the signal? A) Helical domain B) Ras-like domain C) Pleckstrin homology (PH) domain D) SH2 domain

Ans: B. The G-alpha subunit contains a Ras-like domain responsible for GTP binding and hydrolysis, aided by RGS proteins.

41. Agrobacterium tumefaciens transfers T-DNA into plant cells. The virulence genes responsible for recognizing plant wound phenolic signals (like acetosyringone) are: A) virD1/D2 B) virB operon C) virA and virG D) virE2

Ans: C. VirA is the sensor kinase that detects phenolics, and VirG is the response regulator that activates other vir genes.

42. Telomerase is a highly specialized reverse transcriptase that extends the 3' end of chromosomes. Its RNA component in humans is known as: A) hTERT B) hTR (or TERC) C) POT1 D) TRF2

Ans: B. hTERT is the protein catalytic subunit; hTR (TERC) provides the RNA template.

43. Which technique is most appropriate for verifying that a newly discovered transcription factor physically binds to a specific promoter region *in vivo*? A) Northern Blotting B) Chromatin Immunoprecipitation (ChIP) C) Yeast Two-Hybrid Assay D) Flow Cytometry

Ans: B. ChIP crosslinks proteins to DNA, isolates the complex using an antibody against the protein, and sequences the bound DNA.

44. Competitive inhibition of an enzyme alters kinetics such that: A) Vmax decreases, Km is unchanged B) Vmax is unchanged, Km increases C) Vmax and Km both decrease D) Vmax and Km both increase

Ans: B. High substrate concentration can outcompete the inhibitor, reaching normal Vmax, but higher [S] is needed, meaning apparent Km increases.

45. In eukaryotic translation initiation, which factor recognizes the 5' 7-methylguanosine cap of the mRNA? A) eIF2 B) eIF3 C) eIF4E D) eIF5

Ans: C. eIF4E specifically binds the 5' cap as part of the eIF4F complex.

46. The transition from early to late endosomes is mediated by a "Rab cascade." This primarily involves the conversion of: A) Rab1 to Rab2 B) Rab5 to Rab7 C) Rab11 to Rab4 D) Rab8 to Rab10

Ans: B. Active Rab5 recruits Rab7-GEF. Once Rab7 activates, it recruits Rab5-GAP, turning off Rab5 and maturing the endosome.

47. Which mutation in the lac operon would cause the strongest trans-dominant repression even in the presence of lactose? A) I- (null repressor) B) Is (super-repressor) C) Oc (constitutive operator) D) Z- (null beta-galactosidase)

Ans: B. Is mutants cannot bind allolactose but can still bind the operator, shutting down the operon entirely (trans-dominant).

48. During DNA replication, DNA ligase catalyzes the formation of a phosphodiester bond. In E. coli, this enzyme derives its necessary energy directly from: A) ATP B) GTP C) NAD+ D) FAD

Ans: C. Bacterial DNA ligase uses NAD+ for adenylation, whereas eukaryotic and viral ligases use ATP.

49. In the extrinsic pathway of apoptosis, the Death-Inducing Signaling Complex (DISC) recruits and activates: A) Procaspase-9 B) Procaspase-8 C) Cytochrome C D) Apaf-1

Ans: B. FADD recruits Procaspase-8 to the DISC, where it undergoes induced proximity activation.

50. A protein with an isoelectric point (pI) of 4.5 is placed in a buffer of pH 7.5. What will be its net charge, and which ion-exchange column will it bind to? A) Positive; Cation-exchange B) Negative; Anion-exchange C) Positive; Anion-exchange D) Negative; Cation-exchange

Ans: B. At pH > pI, the protein loses protons and becomes negatively charged, binding to positively charged Anion-exchange beads.

51. The "Wobble" hypothesis explains how one tRNA can recognize multiple codons. If the 1st anticodon base is Inosine (I), it can pair with which mRNA codon bases? A) U, C, A B) A, G C) C, G D) U, G

Ans: A. Inosine at the wobble position can bond with U, C, or A.

52. During base excision repair (BER), the abasic site is recognized and cleaved by: A) DNA glycosylase B) AP endonuclease C) DNA polymerase beta D) UvrABC excinuclease

Ans: B. Glycosylases remove the base, creating an AP site. AP endonuclease then cleaves the DNA backbone at that site.

53. In plant biotechnology, a common method to produce virus-free plants from an infected parent is: A) Protoplast fusion B) Meristem culture C) Anther culture D) Somatic embryogenesis

Ans: B. Apical meristems are highly dividing tissues and generally free from viral infections due to lack of vascular connections.

54. Which of the following is a classic uncoupler of oxidative phosphorylation that dissipates the proton gradient? A) Rotenone B) Oligomycin C) 2,4-Dinitrophenol (DNP) D) Antimycin A

Ans: C. DNP carries protons across the inner mitochondrial membrane, bypassing ATP synthase and releasing energy as heat.

55. In Drosophila embryonic development, bicoid and nanos are examples of: A) Gap genes B) Pair-rule genes C) Maternal effect genes D) Hox genes

Ans: C. Their mRNAs are deposited by the mother into the egg to establish anterior-posterior polarity.

56. Which of the following lipids is primarily confined to the inner leaflet of the plasma membrane, where its exposure to the outside signals apoptosis? A) Phosphatidylcholine B) Phosphatidylserine C) Sphingomyelin D) Glycolipids

Ans: B. Flippases keep PS on the inner leaflet. During apoptosis, scramblases expose it to the exterior, signaling macrophages.

57. The technique of measuring real-time bimolecular interactions using changes in the refractive index near a gold film is: A) Circular Dichroism (CD) B) X-Ray Crystallography C) Surface Plasmon Resonance (SPR) D) FRET

Ans: C. SPR provides real-time kon and koff kinetic data without labeling the molecules.

58. The major difference between a genomic library and a cDNA library is that the cDNA library lacks: A) Exons B) Introns and promoters C) Coding sequences D) Poly-A tails

Ans: B. cDNA is reverse-transcribed from mature mRNA, which has already had introns spliced out and lacks regulatory promoter regions.

59. The tumor suppressor Rb is active when it is: A) Hyperphosphorylated B) Hypophosphorylated C) Ubiquitinated D) Bound to cyclins

Ans: B. In its hypophosphorylated state, Rb binds and inhibits E2F. Phosphorylation by CDKs inactivates Rb.

60. In MALDI-TOF mass spectrometry, the separation of ions in the flight tube is strictly based on their: A) Isoelectric point B) Hydrophobicity C) Mass-to-charge ratio (m/z) D) Magnetic resonance

Ans: C. Time-Of-Flight (TOF) separates ions by their m/z ratio; smaller, more highly charged ions fly faster to the detector.