MOCK NEET SOLUTION SET 2017 -1- PHYSICS 1. A system is taken from state A and B along two different path 1 and 2 .The heat absorbed and work done by the system along these two path are Q1 and Q2 , and W1and W2 respectively . Then 1. Q1 =Q2 2. W1 =W2 4 3. Q1 -W1 =Q2 – W2 4. Q1 +W1 =Q2 + W2 Explanation : A path or operation by which a thermodynamic system changes from one state to another is called a process. In both cases internal energy change is same. Total energy of the system must remain same whatever thermal energy (heat) q is absorbed by the system is not destroyed but gets converted into work done in part, the remaining part augmenting the internal energy of the system. 2. If the frequency of the rotating platform is u and the distance of a boy from the center is r, what is the area swept out per second by the line connecting the boy to the center? 1. πrv 2. 2π rv 4 3. πr2v 4. 2πr2v Explanation : Area swept out per second = Area swept in one rotation × Number of rotation per unit time . = π r2v 3. The radius of gyration of a uniform rod of length L about an axis passing through its center of mass is 4 1. L√12 2. L2/√12 3. L√3 4. L√2 Explanation : I = MK²= ML² / 12, 4" K = L / √12 -2- 4. The part of the spectrum of the electromagnetic radiation used to cook food is 1. ultraviolet rays 2. cosmic rays 3. X rays 4 4. microwaves Explanation : Microwaves are used to cook food. Micro wave oven is a domestic application of these waves. 5. If S is stress and Y is young’s modulus of material of a wire , then the energy stored in the wire per unit volume is 4 1. S² / 2Y 2. 2Y / S² 3. S / 2Y 4. 2S² Y Explanation : Energy stored per unit volume = 1 / 2 stress strain = 1 / 2 stress / Y = 1 / 2 S² / Y 6. The first ball of mass m moving with a velocity u collides head on with the second ball of mass m at rest. If the coefficient of restitution is e, the ratio of final velocity of the second ball to the initial velocity of the first ball is 1. 1− e 1+ e 2. 1+ e 1− e 3. 1+ e 2 4. 1-e 2 -3- 7. Two identical coils carrying equal current have a common center and their planes are at right angle to each other. What is the ratio of magnitude of the resultant magnetic field and the field due to one coil along its axis? 1. 2 : 1 2. 1 : 1 3. 1 : √2 4 4. √2 : 1 Explanation : The resultant magnetic field is “2 B The ratio = “2 B / B = “2 : 1 8. When a hydrogen atom is excited from the ground state, 1. K.E and P.E both will increase 2. K.E and P.E both will decrease 3. K.E increases but P.E decreases 4 4. K.E decreases but P.E increases Explanation : Since the hydrogen atom is excited from ground state the height increases and hence the PE increases whereas the K.E decreases. 9. A satellite is circling around the earth at a distance x from the center of Earth . If the radius of the circular orbit is reduced by 1%, then the speed will increase by 1. 0.5% 2. 1% 3. 2% 4. 3% Explanation : As the speed is inversely proportional to r, differentiating both sides w.r.t. r, we get (dvo /vo ) × 100 = 0.5% 10. A particle is moving in a circle with uniform speed. Its motion is 1. periodic, simple harmonic 2. periodic 4 3. periodic but not harmonic 4. non periodic harmonic -4- Explanation : This motion in a circle is just periodic as it is a circle, but is not harmonic as it does not oscillate. 11. When a conducting slab wholly fills the space between the two plates of a capacitor, its capacitance 4 1. becomes infinite 2. become four times the original one 3. remains same 4. becomes zero Explanation : The slab when covers the full distance d, i.e, if t = d, then the capacitance value denominator becomes 0. Hence the capacitance becomes infinite. 12. The electric lines of force at any point do not intersect because 1. the intensity at that point becomes zero 2. the intensity at that point shows infinity 3. the intensity at that point does not exist. 4 4. the intensity at that point shows two different directions Explanation : Electric lines of forces represent direction of electric field and at a point where these lines intersect the field would show two different directions which is not possible 13. If force is 2 N , then displacement is 3 cm. If displacement is 5 cm , force is 1. 1.2 N 4 2. 3.33 N 3. 2 N 4. 0.36 N Explanation : In S.H.M., force ”” displacement F = 5k, F/2 = 5/3 F = 10/3 N = 3.33 N -5- 14. A 4 µF capacitor is charged to 400V. If its plates are joined through the resistance, then heat produced in resistance will be 1. 0.16 J 4 2. 0.32 J 3. 0.64 J 4. 1.28 J Explanation : The given capacitance is 4 F and voltage is 400V. We know that Heat produced = electrical energy stored. Hence CV²/2 = (4 × 10¯v × 16000)/2= 0.32 J . 15. Given below is a list of electromagnetic spectrum and its modes of production. Which one does not match? 1. Gamma rays – Radioactive decay of the nucleus 4 2. Ultraviolet -Magnetron valve 3. Infra-red – Vibration of atoms and molecules 4. X – rays -coolidge tube Explanation : Ultraviolet ray is not produced by Magnetron valve . 16. A steam engine deliver 5.4 × 10x J of work per minute and absorbs 3.6 × 10y J of heat per minute from its boiler. What is the efficiency of the engine? 1. 10% 2. 12% 4 3. 15% 4. 18% -6- 17. When cooking oil is heated in a frying pan , the oil moves around in the pan more easily when it is hot . The main reason for this is that with rise in temperature , there is a decreases in 1. surface tension 4 2. viscosity 3. angle of contact 4. density Explanation : Viscosity is a fluid’s resistance to internal motion or flow and results from intermolecular friction. The result is that liquids show a reduction in viscosity with increasing temperature. 18. Magnification at least distance of distinct vision of a simple microscope having its focal length 5 cm is 1. 2 2. 4 3. 5 4 4. 6 19. Ratio of the largest to the shortest wavelength in Lyman series of hydrogen spectra is 1. 25 / 9 2. 17 / 6 3. 9 / 5 4. 4 / 3 Explanation : For Lyman series, ëmax / ëmin = 4 / 3 20. If the balancing lengths corresponding to two cells are 400 cm and 800 cm respectively, then the ratio of e.m.f s of two cells will be 4 1. 1 : 2 2. 2 : 1 3. 3 : 6 4. 6 : 4 -7- Explanation : E1• / E2 = l1• / l2 = 400/800 = 1/2 =1:2 21. Lenz’s law provides a relation between 1. current and magnetic field 2. inducedemf and the magnetic flux 3. force on a conductor and magnetic field 4. current and induced emf Explanation : The Lenz’s law provides a relation that change in flux induces an EMF in the coil. 22. The mutual inductance of a coil does not depend on 1. number of the turn of the coil 2. geometrical properties of the coil 3. medium between the coils 4 4. permeability Explanation : The mutual inductance of a coil is independent of the permeability. 23. A car runs at a constant speed on a circular track of radius 100m, taking 62.8 seconds for every circular lap. The average velocity and average speed for each circular lap respectively is 1. 10ms-1, 0 2. 0, 0 4 3. 0, 10ms-1 4. 10ms-1, 10ms-1 Explanation : In one circular lap, the displacement = zero The displacement covered = 2πr = 2 × 3.14 × 100m Average velocity = Displacement/Time taken = (0/62.8) = 0 Average speed = Distance travelled/ Time taken = 2 × 3.24 × (100m/62.8s) = 10ms-1 -8- 24. Angle between the plane of vibration and plane of polarization is 1. 30p 4 2. 90p 3. 60p 4. 70p Explanation : Angle between the plane of vibration and plane of polarization is 900 25. Three measurements are made as 18.425 cm, 7.21 cm and 5.0 cm. The sum of measurements upto correct number of significant figures is 1. 30.635 cm 2. 30.64 cm 3. 30.63 cm 4 4. 30.6 cm Explanation : In the question there are 3 numbers given. We have to add the 3 numbers and come out with an answer that contains the correct number of significant figures. We can see that the first number i.e 18.425 has 3 decimal places the second number 7.21 has 2 decimal places the third number 5.0 has 1 decimal place The least number of decimal places is 1. So the sum of measurement would have 1 decimal place 18.425 + 7.21+ 5.0 = 30.635 cm = 30.6 cm Addition or subtraction of measurements must contain as many decimal places as there are in the measurement containing the least number of decimal places. 26. Resultant of two SHMs at right angles with same amplitude and frequency but phase change by ð/2 is 4 1. a circle 2. ellipse 3. parabola 4. sinusoidal wave -9- Explanation : When the two resultants are at right angles differing by ð/2 the resultants inscribe a circle of the radius of the amplitude. 27. The Earth’s atmosphere is held to itself by 1. winds 2. clouds 4 3. gravity 4. rotation Explanation : The earths atmosphere is held to the earth due to the gravitational pull of the earth. It binds this thick layer to the planet due to its strong gravitational pull. 28. Wattless current is a current flowing through a 1. pure resistor 2. semiconductor 3. circuit containing a resistance and an inductance in series 4 4. pure inductor Explanation : Wattless current is the current that flows through pure inductor. Power consumed in the circuit due to the flow of wattless current is zero. 29. A body constrained to move in the z direction, is subjected to a force given by F = - 2i + 15j + 6k N. What is the work done by the force in moving the body a distance 10 m along the z-axis? 1. -20 J 2. 150 J 4 3. 60 J 4. 80 J Explanation : W = [-2i + 15j + 6k]. 10k = 60J 30. Surface tension has the same dimensions as that of 1. Coefficient of viscosity 2. momentum 4 3. spring constant 4. frequency - 10 - Explanation : Surface tension = Force = [MLT-2] = [ML0T-2].......(i) Length [L] Force = [MLT-2] = [ML0T-2].......(ii) Length [L] From (i) and (ii) we can see that surface tension spring constant have same dimensions Surface constant = 31. Two rings of the same radius and mass are placed such that their centers are at common point and their planes are perpendicular to each other . The moment of inertia of the system about an axis passing through the center and perpendicular to the plane of one of the rings is (mass of the ring =m,radius =r) 1. 1 / 2 mr² 2. mr² 4 3. 3 / 2 mr² 4. 2 mr² Explanation : Because the planes of two rings are mutually perpendicular and centers are coincident , hence an axis , which is passing through center of one of the rings and perpendicular to its plane , will be along the diameter of other ring .Hence ,moment of inertia of the system = I cm + Idiameter = mr² + mr² / 2 = 3 / 2 mr² 32. A simple pendulum is oscillating with amplitude ‘A’ and angular frequency ‘ ‘. At displacement ‘x’ from mean position, the ratio of kinetic energy to potential energy is 1. X2 A2 - X2 2. X2 - A2 X2 3. A2 - X2 X2 4. A-X X - 11 - 33. The idea of quantum nature of light emerged in an attempt to explain 1. photoelectric effect 4 2. black body radiation 3. thermionicemmission 4. atomic spectra Explanation : A black body in thermal equilibrium emits electromagnetic radiation called black body radiation. The radiation has a specific spectrum and intensity that depends only on the temperature of the body. Max Planck, in 1901, accurately described the radiation by assuming that electromagnetic radiation was emitted in discrete packets or quanta. 34. The molecular weights of oxygen and hydrogen are 32 and 2 respectively . The root mean square velocities of oxygen and hydrogen at NTP are in the ratio 1. 4 : 1 2. 1 : 16 3. 16 : 1 4 4. 1 : 4 35. The Hubble constant has the dimension of 1. time 4 2. (time)-1 3. length 4. mass Explanation : Hubble constant, H = speed of galaxy/Distance of galaxy from us H= speed/distance = 1/time = (time)-¹ - 12 - 36. A thermoelectric refrigerator works on 1. Joule effect 2. Seebeck effect 3. Thomson effect 4 4. Peltier effect Explanation : A thermoelectric refrigerator works on Peltier effect of heating and cooling of sides. 37. The mean free path of a gas depends on the molecular diameter (ó) as 1. ó 2. ó- ¹ 4 3. ó- ² 4. ó² Explanation : The free path of a gas is inversely proportional to the square of its molecular diameter. 38. Alternating current can be produced by 1. a transformer 2. a choke coil 4 3. a dynamo 4. a galvanometer Explanation : Alternating current can be produced by a dynamo . 39. The phenomenon inverse to photoelectric effect is 1. Compton effect 2. Raman effect 3. Pair production 4 4. Production of X-rays Explanation : When fast moving electrons strike on high atomic weight substance, X – ray is produced and when radiation of sufficient frequency incident on the metal surface, electrons are emitted ie. Photoelectric effect takes place, it means fast moving electrons produce X – ray and X – ray i.e. radiations produce photoelectrons. Hence, X – ray is the inverse phenomenon of photoelectric effect. - 13 - 40. Electric intensity at a point outside a charged spherical conductor surrounded by air is 6 N/C . If the space around the conductor is filled with a medium of dielectric constant 3, then the electric intensity at the same point will be 1. 20 N/C 4 2. 2 N/C 3. 2.5 N/C 4. 6.25 N/C 41. Two equal forces are acting at a point with an angle of 60° between them. If the resultant force is equal to 40√3 N, the magnitude of each force is 4 1. 40 N 2. 20 N 3. 80 N 4. 30 N Explanation : Given : Force F1• = force F2 = F or, F1• = F2 = F Resultant force R = 40√3 N Angle between two forces F1 and F2 is θ = 60° 4 = R = √F1 ² + F2 ² + 2F1 F2 cosθ or, 40√3 = √F² + F² + 2F² cos 60° = √3F or, F = 40 N 42. In elastic collision 4 1. both momentum and kinetic energy are conserved. 2. both momentum and kinetic energy are not conserved. 3. only mechanical energy is conserved. 4. only momentum is conserved. Explanation : An elastic collision is defined as one in which both conservation of momentum and conservation of kinetic energy are observed. This implies that there is no dissipative force acting during the collision and that all of the kinetic energy of the objects - 14 - before the collision is still in the form of kinetic energy afterward. 43. Sun is visible a little before the actual sunrise and until a little after the actual sunset . This is due to 1. total internal reflection 2. reflection 4 3. refraction 4. Polarization Explanation : The sun is visible a little before the actual sunrise and until a little after the actual sunset due to refraction of light through the atmosphere . 44. Sensitivity of a moving coil galvanometer can be increased by 1. decreasing the number of turns of coil 4 2. increasing the number of turns of coil 3. decreasing the area of a coil 4. by using a weak magnet 45. Pushing force making an angle è with the horizontal is applied on a block of weight W placed on a horizontal table .If the angle of friction is ϕ ,the magnitude of force required to move the body is equal to - 15 - - 16 - CHEMISTRY 46. When 4 g of iron is burnt to ferric oxide at constant pressure, heat is evolved. What is the enthalpy of formation of ferric oxide? (At .wt . of Fe = 56) 1. -40.99 kJ 2. -81.98 kJ 3. +818.8 kJ 4 4. -819.8 kJ Explanation : Weight of iron burnt = 4 g; Heat liberated = 29.28 kJ and atomic weight of iron = 56 n ferric oxide (Fe2O3 ) , moles of iron or 2 × 56 = 112 g of iron are burnt. Also when 4 g of iron are burnt, then heat liberated = 29.28 kJ. Therefore when 112g of iron are burnt, then heaat liberated 29.28 × 112 / 4 = -819.8 kJ 47. The monomer units of PTFE is 1. F3 C = CF3 4 3. F2C = CF2 2. 4. FCIC = CF2 CI2 CH = CH3 Explanation : PTFE is polytetrafluoro ethylene (Teflon) having momomeric unit, F2 C = CF2 48. In acidic medium, dichromatic ion oxidses ferrous ion to ferric ion. If the gram molecular weight of potassium dichromate is 294 grams, its gram equivalent weight is …...grams 1. 294 2. 127 3. 49 4 4. 24.5 Explanation : In acidic medium K2Cr2O7 acts as strong oxidising agent and itself gets reduced to Cr3+ +6 Cr2 O7 ²- + 6e- --> 2Cr3+ Equivalent weight of K2Cr2 O7 = Mlecular weight / 6 = 264/6 = 49 49. Bithional is 1. analgesic 3. antibiotic Explanation : Bithional is antiseptic 4 2. antacid 4. antiseptic - 17 - 50. Which among the following group 15 element forms most stable pentavalent compound? 4 1. Phosphorus 2. Antimony 3. Bismuth 4. Arsenic No Explanation 51. The rate law expression for four reactions are given below . In which case , the percentage increase in the rate of reaction would be maximum when the concentration of A is doubled ? 1. rate = K[A] 2. rate = K[A] 3 / 2 3. rate K[A]° 4 4. rate K[A]² Explanation : Larger the order of reaction, more the percent increase in the rate of reaction for a given increase in concentration. 52. Which transition metal is different among the following? 1. Cu 4 2. Hg 3. Zn 4. Cr Explanation : Hg metal is different from the rest of the transition metals. 53. Gabriel phthalimide reaction is used for preparation of 1. primary aromatic amines 2. secondary amines 4 3. primary aliphatic amines 4. tertiary amines Explanation : Gabriel phthalimide reaction is used for the preparation of primary aliphatic amines . 54. Barbiturates are 4 1. sleep producing 3. non-hypnotic 2. 4. antibiotics food preservative Explanation : Barbiturates are sleep producing pills 55. Pure hydrogen is obtained by electroylsis of a solution 1. KOH 2. NaOH 4 4. Both (a) and (b) 3. Ba(OH)2 - 18 - Explanation : 56. A solution conatining components is prepared by mixing n-heptane and ethanol. Which one of the following statements is correct regarding the behaviour of the solution ? 1. A -B attraction force is greater than A-A and B-B 2. A -B attraction force is less than A-A and B-B 4 3. A -B attraction force remains same as A-A and B-B 4. volume of solution is different from sum of volumes of solute and solvent Explanation : Raoult’s law is valid for ideal solutions only. The element of non-ideality enters into the picture when the molecules of the solute and solvent effect each others inter molecular forces.. A solution when A-B attraction force remains same as A-A and B-B. 57. Amongst the C-X bond (where X = CI Br, I), the correct bond energy order is 4 1. C – CI > C – Br > C – I 2. C – I > C – CI > C – Br 3. C – Br > C – CI > C – I 4. C – I > C – Br > C - CI Explanation : C – CI bond contains maximum ionic character due to electronegatively difference thus it is most stable and have maximum bond energy. Order of bond energy is C – CI > C – Br > C – I 58. One mole of acidified K‚ Cr‚ O‡ on reaction with excess KI will liberate .......mole (s) of I2 1. 6 2. 1 3. 7 4 4. 3 Explanation : Cr2 O7 2- + 14H+ + 6I- --> 2Cr3+ + 7H2 O +3I2 Thus, 3 moles of I‚ are liberated from 1 mole of K2Cr2O7 - 19 - 59. The number of isomeric primary alcohols of the molecular formula C4 H10O is 1. 1 4 2. 2 3. 3 4. 4 Explanation : The isomers are : (1) CH3CH2CH2CH2OH (2) 60. The drug used for the treatment of typhoid is 1. Opium 2. Procain 4 3. Chloramphenicol 4. Xylocain Explanation : Typhoid can be treated using Chloramphenicol as the drug reagent. 61. Hinsberg reagent is 1. aliphaticsulphonyl chloride 2. phthalamide 4 3. aromaticsulphonyl chloride 4. anhydrousZnCl2 + conc .HCl Explanation : Hinsberg’s reagent is benzenesulphonyl chloride (C6H5SO2Cl). 62. The statement that is NOT correct is : 1. afurance lined with Haematite is used to convert cast iron to wrought iron. 4 2. collectors enhance the wettability of mineral particles during froth floatation. 3. invapour phase refining , metal should form a volatile compound. 4. copper from its low grade ores is extracted by hydrometallurgy. Explanation : Collectors are added to enhance the non – wettability of mineral particles during froth floatation. - 20 - 63. The O-O-H bond angle in H‚ O‚ is 1. 106° 2. 3. 120° 4 4. 109°28' 97° Explanation : O—O—H bond angle in H2O2 is 97° 64. (i) Tensile strength of vulcanized rubber is almost ten times more than raw rubber. (ii) Elasticity of raw rubber is very high. 4 1. (I) is true (ii) is false 2. 3. Both (I) & (ii) are true 4. (I) is false (ii) is true Both (I) & (ii) are false. Explanation : Natural rubber is soft and sticky and after vulcanisation its strength increases due to cross linked formed between different monomer units. 65. Glucose is oxidised to carbon dioxide and water with oxygen in the presence of enzyme: 1. Maltose 2. á-amylase 3. Lactose 4 4. Oxidase Explanation : An oxidase is an enzyme that catalyzes an oxidation-reduction reaction, especially one involving dioxygen (O2) as the electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced to water (H2O) or hydrogen peroxide (H2O2). 66. 50 mL of gas A effuses through a pin hole in 146 seconds. The same volume of CO2 under identical condition effuses in 115 seconds. The molar mass of A is 1. 44 2. 35.5 4 3. 71 4. None of these - 21 - 67. Which one of the following statements is correct for alkaline earth metals ? 1. They are diatomic and form ions of the type M²{ 2. They are highly electronegative elements 3. They are monoatomic and form ions of the type Mz 4 4. They are monoatomic and form of the type M²z Explanation : Alkaline earth metals are monoatomic and form dipositive ions M²z . 68. 10 mL of water requires 1.47 mg of K2Cr2O7 (M. wt .= 294) for oxidation of dissolved organic matter in it in the presence of H2SO4. The C.O.D of water sample is 1. 8 ppm 4 2. 6.4 ppm 3. 16.8 ppm 4. 4.9 ppm Explanation : 10 mL water – 1.47 × 10-³ g K2Cr2O7 10v mL water – 147 g K2Cr2O7 49 g of K2Cr2O7 – 8g O2 147 g of K2Cr2O7 – 24 g of O2 69. Which of the following is an electrophile? 1. SnCI„ 2. 3. NO‚ z 4 4. SOƒ All of these Explanation : SO3, SnCI4 and NO2+ all acts as electrophiles. - 22 - 70. In the ground state configuration of Mn, how many electrons are present in the ‘N’ shell? 1. 13 4 2. 2 3. 15 4. 3 Explanation : N shell is the fourth shell. Hence the number of electrons in ground state are 2. 71. Molarity 4 1. 2. 3. 4. is defined as the number of moles of solute dissolved in one dm³ of the solution the number of moles of solute dissolved in 1 kg of solvent the number of moles of solute dissolved in 1 dm³ of the solvent the number of moles of solute dissolved in 100 ml of the solvent No Explanation 72. Which of the following exhibits the weakest intermolecular forces? 4 1. He 2. NH3 3. Hcl 4. H‚ O Explanation : In NH3, HCl, H2O intermolecular forces is due to H-bonding but in He there is weak intermolecular van der waals force of attraction. 73. If the nitrogen atom had electronic configuration 1s² 2s² 2p³ , because the electrons would be closer to the nucleus . Yet 1s7 is not observed because it violates 1. Heisenberg ‘suncertainity principle 2. Hund’s rule 4 3. Pauli’s exclusion principle 4. Bohr postulate of stationary orbits Explanation : As per Pauli’s exclusion principle, “no two electrons in the same atom can have all the four quantum numbers equal or an orbital cannot contain more than two electrons and it can accommodate two electrons only when their directions of spins are opposite.’’ 74. An organic amino compound reacts with aqueous nitrous acid at low temperature to produce an oily nitrosoamine. The compound is 1. (CH3 CH2‚ )3 N 2. CH3 CH2‚ NHCH2‚ CH3 3. CH3 CH2‚ NH2 4. CH3 NH2 Explanation : Both aliphatic aromatic secondary amines react with nitrous acid to give a yellow oily liquid called nitrosoamines . - 23 - 75. Which of the following has least electron affinity? 1. O 2. N 4 3. Ar 4. F Explanation : Noble gases have no tendency to accept electrons and thus their electron affinity is zero. 76. When atoms are placed at the corners of all 12 edges of a cube , the number of atoms present per unit cell is : 4 1. 1 2. 2 3. 4 4. 6 No Explanation 77. Which of the following ion of lanthanides is/are coloured? 1. Ce+ ³ 2. Tb+³ 4 4. both b and c 3. Er+ ³ Explanation : Both Tb+ ³ and Er+ ³ are colored in nature as they can have their ions displaced. 78. Octane number is 1. number of carbon atoms is octane 2. number of molecules of octane formed in cracking of 1.0 g of gasoline 4 3. number of hydrogen atoms in octane 4. number for representing standard rating of fuel. Explanation : The octane number is one of the characteristics of spark-ignition fuels such as gasoline. Quality of fuel is graded in terms of octane number. 79. Which one of the following can adsorb larger volume of hydrogen gas ? 1. Finely divided nickel 4 2. Colloidal solution of palladium 3. Finely divided platinum 4. Colloidal Fe(OH)3 - 24 - Explanation : Colloidal solution of palladium has maximum surface area therefore it can adsorb larger volume of hydrogen gas . 80. Considering H2O as a weak field ligand, the number of unpaired electrons in [Mn(H2 O)6 ]²+ will be (At . no of Mn = 25 ) 4 1. five 2. two 3. four 4. three Explanation : Mn(II) : 3d5. In the presence of weak field ligands, there will be no pairing of electrons. Therefore, it will form high spin complex and will have five unpaired electrons. 81. Which of the following has highest ionizing power ? 4 1. α – rays 2. β - rays 3. γ – rays 4. all of these Explanation : α – rays have highest ionizing power due to high +vecharge . 82. CH3 – Mg – Br is organometallic in nature due to the presence of 1. Mg – Br bond 4 2. C – Mg bond 3. C – Br bond 4. C – H bond Explanation : The organometallic character is due to the presence of C – Mg bond . 83. At high pressure, short-range interactions which become significant when molecules are almost in contact are 1. electrostatic interactions 2. van der Waal’s interactions 3. intermolecular interactions 4 4. repulsive interactions Explanation : At high pressure, short-range interactions which become significant when molecules are almost in contact are repulsive interactions. In physical chemistry, the van der Waals forces (or van der Waals interaction), are the residual attractive or repulsive forces between molecules or atomic groups that do not arise from a covalent bond, or ionic bonds. - 25 - 84. When concentration of the reactant in reaction A--> B is increased by 8 times the rate increases only 2 times. The order of the reaction would be 1. 2 4 2. 1/3 3. 4 4. 1/2 Explanation : Here, 8n = 2 n = 1 / 3. 85. Which property of an element is always a whole number? 1. Atomic weight 2. Equivalent weight 4 3. Atomic number 4. Atomic volume Explanation : Atomic number is the number of protons present in an atom which cannot be in fractions. 86. In the reaction, 3CuO + 2NH3 --> N2 + 3H2O +3Cu the change of NH3 to N2 involves 4 1. Loss of 6 electrons per mol of N2 2. Loss of 3 electrons per mol of N2 3. Gain of 6 electrons per mol of N2 4. Gain of 3 electrons per mol of N2 Loss of 6 electrons for 2 mol of N2 87. Poisonous gas prevent in the exhaust fumes of car is 1. CH4 2. C2H2 4 3. CO 4. CO2 Explanation : CO is the poisonous gas present in exhaust fumes of car. - 26 - 88. Molarity of 0.2 N H2SO4 is 1. 0.2 3. 0.6 2. 4 4. 0.4 0.1 Explanation : Molarity is half of the normality since the acid present is dibasic Hence, the molarity is 0.1 M. 89. In sodium fusion test of organic compounds, the nitrogen of the organic compound is converted into 1. sodamide 4 2. sodium cyanide 3. sodium nitrite 4. sodium nitrate Explanation : Sodium cyanide (Na + C + N -->NaCN) 90. When a mixture of methane and oxygen is passed through heated molybdenum oxide, the main product formed is 1. methanoic acid 2. ethanal 3. methanol 4 4. methanol - 27 - BIOLOGY 91. Leguminous plants are able to fix atmospheric nitrogen through the process of symbiotic nitrogen fixation. Which one of the following statements is not correct during this process of nitrogen fixation? 1. Leghaemoglobin scavenges oxygen and is pinkish in color 2. Nodules act as sites for nitrogen fixation 3. The enzyme nitrogenase catalyze the conversion of atmospheric N2 to NH3 4 4. Nitrogenase is insensitive to oxygen Explanation : Nitrogenase enzyme of leguminous plants is sensitive to oxygen, Leghaemoglobin (a pinkish pigment) scavenges oxygen and in this way protects nitrogen fixing enzyme nitrogenase which can function only in anaerobic conditions. 92. Which one of the following conditions of the zygotic cell would lead to the birth of a normal human female child? 4 1. Two X chromosomes 2. Only one Y chromosome 3. Only one X chromosome 4. One X and one Y chromosome Explanation : In humans , the female has a pair of X chromosomes (homogametic composition) and the male has XY chromosomes (heterogametic composition). Therefore two normal X chromosomes in zygotic cell lead to the birth of a normal human female child. 93. Dough kept overnight in warm weather becomes soft and spongy because of 1. absorption of CO‚ from atmosphere 4 2. fermentation 3. cohesion 4. osmosis Explanation : Saccharomyces converts starch or sugars to pyruvic acid through EMP pathway.Then this pyruvic acid is converted to acetaldehyde and finally to ethy1 alcohol in the absence of oxygen.This entire process is called fermentation. C6 H12O6 --> 2C2 H5OH + 2CO2 This released carbon dioxide from yeast makes the dough to rise and gives spongy nature to it. - 28 - 94. A patient brought to a hospital with myocardial infarction is normally immediately given 1. penicillin 4 2. streptokinase 3. cyclosporin -A 4. statins Explanation : Streptokinase (Tissue Plasminogen Activator or TPA) is an enzyme obtained from the culture of some haemolytic bacterium streptococcus which is modified genetically to function as clot buster. Therefore, it helps in clearing blood clots inside the blood vessels through dissolution of intravascular fibrin during myocardial infraction. 95. During gamete formation, the enzymes recombinase participate during 1. metaphase -I 2. anaphase -II 4 3. prophase -I 4. prophase -II Explanation : During gamete formation the enzyme recombinase participates during pachytene stage of prophase -I. Crossing over is the exchange of genetic material between two homologous chromosomes. 96. Which of the following is an epidermal cell containing chloroplast? 1. Hydathode 2. Stomata 4 3. Guard cell 4. None of these Explanation : Guard cells are the specialized epidermal cells containing chloroplasts. 97. In a standard ECG which one of the following alphabets is the correct representation of the respective activity of the human heart? 1. S - start of systole 2. T - end of diastole 3. P - depolarisation of the atria 4. R – repolarisation of ventricles Explanation : A normal electrocardiogram (ECG) is composed of a P wave, a QRS wave and a T wave. The P wave is a small upward wave that indicates the depolarisation of the atria. This is caused by the excitation of SA node. - 29 - 98. Cry I endotoxins obtained from Bacillus thuringiensis are effective against 1. nematodes 4 2. bollworms 3. mosquitoes 4. flies Explanation : Bt toxin is insect group-specific and is coded by a gene named cry. These genes were isolated from Bacilusthuringiensis<>/i and incorporated into several crop plants. The proteins encoded by the genes cry Iac and cry IIAb control the cotton bollworms. 99. What is true about ribosomes? 4 1. The prokaryotic ribosomes are 80S, where ‘’S’’ stands for sedimentation coefficient 2. These are composed of ribonucleic acid and proteins 3. These are not composed of ribonucleic acid and proteins 4. These are self – splicing introns of some RNAs. Explanation : Ribosome is a small spherical body within a living cell that is the site of protein synthesis . Ribosomes consist of two subunits one large and one small each of which comprises a type of RNA (called ribosomal RNA) and proteins. 100. Which of the following is not used as a biopesticide? 1. Trichodermaharzianum 2. Nuclear polyhedrosis virus (NPV) 4 3. Xanthomonascampestris 4. Bacillus thuringiensis Explanation : Nucleopolyhedrosis virus (NPV) is used to control Heliothissp, a cosmopolitan pest attacking at least 30 food and fibre yielding crop plant. Trichoderma is used to kill fungal plant pathogen of groundnut, chick pea etc. Bacillus thuringiensis produces protoxin crystal protein which is used to kill lepidopteran& dipteran larvae. 101. Peptide synthesis inside a cell takes place in 1. chloroplast 2. mitochondria 3. chromoplast 4 4. ribosomes Explanation : Peptide synthesis inside a cell takes place in ribosome . Ribosomes found in all cells are involved in proteins synthesis. The major constituents of ribosomes are RNA and proteins present in approximately equal amounts. - 30 - 102. The ‘’eyes’’ of the potato tuber are 1. root buds 2. flower buds 3. shoot buds 4 4. axillary buds Explanation : Potato is the common example of stem tuber. These process axillary buds over their nodes or eyes. The buds produce new plantlets when a stem-tuber or a part of it having an eye is placed in the soil. 103. The upright pyramid of number is absent in 1. pond 4 2. forest 3. lake 4. grassland Explanation : In forests a single tree can support a large number of birds thus base showing producers in pyramid of numbers will be narrower than the next slab showing primary consumers. Hence a upright pyramid of number is not formed in a forest ecosystem. 104. In an area where DDT had been used extensively the population of birds declined significantly because 1. birds stopped laying eggs 2. earthworm in the area got eradicated 3. cobras were feeding exclusively on birds 4 4. many of the birds eggs laid did not hatch Explanation : Higher amounts of DDT disturb calcium metabolism of birds resulting in thinking of egg shells and their premature breaking that kills the embryos. Thus many of the eggs laid by birds did not hatch. 105. Which one of the following pairs of nitrogenous bases of nucleic acids is wrongly matched with the category mentioned against it? 1. Guanine, Adenine – purines 4 2. Adenine, Thymine -Purines 3. Thymine, Uracil -Pyrimdines 4. Uracil, Cytosine -Pyrimidines Explanation : Adenine and guanine are purine bases while thymine , uracil and cytosine are pyrimidine bases - 31 - 106. Which one of the following is not a bioindicator of water pollution? 1. Blood-worms 4 2. Stone flies 3. Sewage fungus 4. Sludge-worms Explanation : Contamination of water bodies by pollutant reduces DO content and sensitive organisms like plankton, molluscs and fish are eliminated. Only a few tolerant species like annelid worm, Tubifex and some insect larvae may survive in highly polluted, low DO water and they may be recognized as indicator species for polluted waters. 107. Pattern baldness in human males is an example of 1. sex-linked traits 2. sex limited traits 4 3. sex influenced traits 4. sex determining traits Explanation : Sex influenced traits are autosomal traits that are influenced by sex i.e. the allele behave as dominant in one sex and as recessive in other. For some traits , if a male has one allele he will show that trait but it will take two alleles for the female to show the same trait e.g, pattern baldness. 108. Prolonged liberal irrigation of agricultural fields is likely to create the problem of 1. acidity 2. aridity 4 3. salinity 4. metal toxicity Explanation : Irrigation induced salinity can arise as a result of the use of any irrigation water, irrigation of saline water etc. Combined with inadequate leaching. Since all surface and ground water contains salts to varying degrees, irrigation is often seen as the primary culprit for bringing salts into the field. 109. An organism used as a biofertilizer for raising soyabean crop is 1. Azotobacter 2. Azospirillum 4 3. Rhizobium 4. Nostoc Explanation : Rhizobium is used as a biofertilizers for raising various crops as it can fix atmospheric nitrogen into soil thereby making it rich in nitrogen. Rhizobium japonicum forms symbiotic association in the roots of the leguminous plants like soyabean. - 32 - 110. Which element is located at the center of the porphyrin ring in chlorophyll? 1. calcium 4 2. magnesium 3. potassium 4. manganese Explanation : The empirical formula of chlorophyll – á molecule is C55H72O5N4Mg. It consist of a porphyrin head and a phytol tail. Porphyrin is a cyclic tetrapyrrole structure, having a magnesium atom in the center. Tail consists of phytol alcohol and it is attached with one of the pyrrole rings. 111. Nucelarpolyembryony is reported in species of 4 1. Citrus 2. Gossypium 3. Triticum 4. Brassica Explanation : In nucellarpolyembryony, some of the nucelar cells surrounding the embryo sac start dividing. In such species, each ovule contains many embryos. Occurrence of more than one embryo in a seed is referred to as polyembryony. Nuclear polyembryony is found in many of the citrus and mango varieties. 112. Which one of the following does not act as a neurotransmitter? 4 1. Cortisone 2. acetylcholine 3. Epinephrine 4. Norepinephrine Explanation : Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a neuron and another cell. Substances that act as neurotransmitters can be categorized into three major groups: some amino acids, peptides and monoamines plus acetylcholine. Cortisone is a glucocorticoid steroid hormone, produced by the adrenal glands and has anti-inflammatory and immune -system suppressing properties. 113. Which one of the following is used as vector for cloning genes into higher organism? 1. Baculovirus 2. Salmonella typhimurium 3. Rhizopusnigricans 4 4. Retrovirus - 33 - Explanation : Retroviruses in animals have the ability to transform normal cells into cancerous cells. These have been transformed into useful vectors for delivering genes of interest in humans. Retroviruses have been disarmed and are now used to deliver desirable genes into animal cells. So once a gene or a DNA fragment has been ligated into a suitable retroviral vector it is transferred into a bacterial, plant or animal host (where it multiples). 114. Root development is promoted by 1. abscisic acid 2. auxin 3. gibberellin 4 4. ethylene Explanation : Ethylene promotes root growth and root hair formatio . In low concentration ethylene is used for initiation of roots and also of lateral roots. 115. Sweet potato is homologous to 1. potato 2. colocasia 3. ginger 4 4. turnip Explanation : Sweet potato is homologous to turnip as both are having same origin i.e both are roots but modified for different function. Sweet potato is a modified root for storage and vegetative while turnip is modified for storage only . 116. In oogenesis haploid egg is fertilized by sperm at which stage? 1. Primary oocyte 4 2. Secondary oocyte 3. Oogonium 4. Ovum Explanation : Seminal plasma in human is rich in fructose, calcium and certain enzymes. Fructose is the source of energy for the sperm. Enzymes nourish and activities the spermatozoa to swim. - 34 - 117. The ciliated columnar epithelial cells in humans are known to occur in 1. eustachian tube and stomach lining 4 2. bronchioles and fallopian tube 3. bile duct and oesophagus 4. fallopian tube and urethra Explanation : The epithelial tissues present on the inner surface of bronchioles and Fallopian tube is ciliated columnar epithelial tissue. 118. A man and a woman , who do not show any apparent signs of a certain inherited disease have seven children (2 daughter and 5 sons). Three of the sons suffer from the given disease but none of the daughter affected. Which of the following mode of inheritance do you suggest for the disease? 1. Sex-linked dominant 4 2. Sex-linked recessive 3. Sex-limited recessive 4. Autosomal dominant Explanation : The trait must be governed by sex-linked recessive gene present on X chromosomes. 119. Which of the following statements is not true for retroviruses? 4 1. DNA is not present at any stage in the life cycle of retroviruses 2. Retroviruses carry gene for RNA dependent DNA polymerase 3. The genetic material in mature retroviruses is RNA 4. Retroviruses are causative agents for certain kinds of cancer in man Explanation : Retroviruses contain RNA as genetic material and this RNA is converted to DNA using enzymes reverse transcriptase 120. Withdrawal of which of the following hormones is the immediate causes of menstruation? 4 1. Progesterone 2. Estrogen 3. FSH 4. FSH-RH Explanation : During menstrual phase the production of LH is considerably reduced. The withdrawal of this hormone causes degeneration of the corpus luteum and therefore progesterone production is reduced. The endometrium degenerates and breaks down and thus menstruation begins. - 35 - 121. During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP ? 1. Glycolysis 2. Krebs’ cycle 3. Conversion of pyruvic acid to acety1 CoA 4 4. Electron transport chain Explanation : In glycolysis 2 ATP molecules are produced from ADP. Further 2NADH2 produced, 2 ×3 = 6 ATP, on oxidative phosphorylation. Similarly in Kreb’s cycle 2 ATP molecules are produced . So the greatest number of ATP molecules are produced in the electron transport chain. 122. The wavelength of light absorbed by Pr form of phytochrome is 4 1. 680 nm 2. 720 nm 3. 620 nm 4. 640 nm Explanation : Phytochrome is the photoreceptor pigments that controls flowering. It has two forms as Pr and Pf r , P r is bluish phytochrome and it absorbs light at 660 to 680 nm of wavelength Pf r is (far red) yellowish green and absorbs light at 730 nm of wavelength. 123. The Indian rhinoceros is a natural inhabitant of which one of the Indian states? 1. Uttarakhand 2. Uttar pradesh 3. Himachal Pradesh 4 4. Assam Explanation : The Indian rhinoceros is an endemic of north -east region of India. Kaziranga national park (Assam) is famous for rhinoceros. 124. Closed vascular bundles lack 1. ground tissue 2. conjunctive tissue 4 3. cambium 4. pith Explanation : Vascular bundle consists of complex tissues, the phloem and xylem. In dicots between xylem and phloem, cambium is present which helps in secondary growth. This type of vascular bundle is called open. While in monocots cambium is absent so these are called closed vascular bundles. - 36 - 125. The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorised as 1. cyanobacteria 2. archaebacteria 3. chemosynthetic autotrophs 4 4. heterotrophic bacteria Explanation : Maximum number of antibiotic are produced by mycelial bacteria known as actinomycetes and most of the actinomycets are saprotrophic (heterotrophic ). Lactic acid bacteria that are used in preparation of curd are also heterotrophic. 126. The bacterium Bacillus thuringiensis is widely used in contemporary biology as 4 1. insecticide 2. agent for production of dairy products 3. source of industrial enzyme 4. indicator of water pollution Explanation : Spores of Bacillus thuringiensis produce the insecticidal cry protein. Therefore spores of this bacterium kill larvae of certain insects. The commercial use is of spores, cry protein and an inert carrier that are sprayed into vulnerable plants like brassicas and fruit trees. 127. Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by 4 1. Base- sugar- phosphate 2. Base – sugar – OH 3. sugar - base – phosphate 4. Sugar – phosphate Explanation : Each nucleotide consists of three distinct units-a phosphate group derived from phosphoric acid, a pentose sugar and a ring shaped nitrogenous base. The base-sugar combination without phosphate group is called nucleoside. A nucleotide is formed by the reaction of sugar portion of nucleoside with phosphoric acid through dehydration e.g adenosine monophosphate is composed of ribose, adenine and phosphate. - 37 - 128. Which one of the following groups of animals is bilaterally symmetrical and triploblastic? 4 1. Aschelminthes (round warms) 2. Ctenophores 3. Sponges 4. Coelenterates (Cnidarians ) Explanation : Aschelminthes is a superphylum consisting of pseudocoelomates. These are mostly aquatic, free living or parasitic. Their body is slender, bilaterally symmetrical and triploblastic. 129. In human female which of the following is incorrect? 1. Menstrual cycle takes 28 days 2. Menopause occurs at 45-55 years 4 3. The ovulated egg released during pregnancy dies 4. Menstruation takes 4 days. Explanation : During pregnancy ovulation does not occur hence there is no question of release or death of eggs. 130. Chlorenchyma is known to develop in the 1. cytoplasm of Chlorella 2. mycelium of a green mould such as Aspergillus 4 3. spore capsule of a moss 4. pollen tube of pinus Explanation : Chlorenchyma or assimilatory parenchyma consists of parenchymatous cells that possess abundant chloroplasts capable of photosynthesis. A spore capsule of moss can perform photosynthesis because of the presence of chlorenchyma. 131. What is common between vegetative reproduction and apomixis? 1. Both are applicable to only dicot plants 2. Both by pass the flowering phase 3. Both occur round the year 4 4. Both produce progeny identical to the parent Explanation : Apomixis is a reproductive process in plants that superficially resembles normal sexual reproduction but in which there is no fusion of gamete. The embryos develop simply by division of a diploid cell the ovule. So the progenies produced are identical to the parent. - 38 - 132. When two unrelated individual or lines are crossed, the performance of F1 hybird is often superior to both its parents. This phenomenon is called 4 1. heterosis 2. transformation 3. splicing 4. metamorphosis Explanation : The increased vigour displayed by the offspring from a cross between genetically different parent is called heterosis. Hybrids from across between different crop varieties (F1 hybrids) are often stronger and produce better yields than the original varieties. 133. In germinating seeds fatty acids are degraded exclusively in the 1. peroxisomes 2. mitochondria 3. proplastids 4 4. glyoxysomes Explanation : Glyoxysomes are small, spherical vesicles enclosed by a single unit membrane. Glyoxysomes are generally found in cells of yeast, Neurospora and in germinating fatty seeds where fat is being converted into carbohydrates i.eglyoxylatecycle(gluconeogenesis). 134. Which one of the following is correct pairing of a body part and the kind of muscle tissue that moves it? 1. Biceps–Smooth muscle of upper arm fibres 2. Abdominal-smooth muscle Wall 4 3. Iris – Involuntary smooth muscle 4. Heart – Involuntary wall unstriated muscle Explanation : Smooth muscles are called as involuntary muscles as action of these muscles is controlled by autonomic nervous system i .e , not under the control of animal’s will. Iris of eyes consist of smooth involuntary muscles. 135. Which of the following are used in gene cloning? 1. Nucleoids 2. Lomasomes 3. Mesosomes 4 4. Plasmids - 39 - Explanation : Plasmid is a small circular double stranded DNA molecule present in the cytoplasm of the bacterial cell.It can replicate indepently of bacterial chromosome. Due to this characteristic of plasmid, it is used as the vector (vectors are for the transferring of a piece of DNA to target gene) in gene cloning. 136. Which of the following happen in the common cockroach? 1. Malphighian tubules are excretory organ projecting out from the colon 2. Oxygen is transported by haemoglobin in blood 3. Nitrogenous excretory product is urea 4 4. The food is ground by mandibles and gizzard Explanation : Mouth part of cockroach contain two mandibles which bears teeth. When both the mandibles work simultaneously in a horizontal plane and the food matter is cut and masticated into fine and smaller pieces. Gizzard is a part of alimentary canal . It bears six muscular folds which are covered by chitinous conical plates, the teeth used for grinding the food. 137. Ascorbic 1. 4 2. 3. 4. acid is known as Vitamin B Vitamin C Vitamin E Vitamin D Explanation : Vitamin C is a water soluble versatile vitamin. It is found in citrus fruits, amla, tomato, etc.It is known as ascorbic acid due to its anti-scorbutic property. 138. The fleshy receptacle of syconus of fig encloses a number of 1. berries 2. mericarps 4 3. achenes 4. samaras Explanation : Syconus develop from hypanthodium type of inflorescence. The flask shaped fleshy receptacles encloses female flower which produces small achene like fruitlets and has a small pore protected by scale leaves. Examples include syconus of fig. 139. A person who is on a long hunger strike and is surviving only on water will have 1. less amino acids in his urine 2. more glucose in his blood 4 3. less urea in his urine 4. more sodium in his urine - 40 - Explanation : During starvation the body must rely on body proteins for the amino acids. On high protein diets the carbon skeletons of the amino acids are oxidized for energy or stored as fat and glycogen, but the amino nitrogen must be excreted. To facilitate this process, enzymes of the urea cycle are controlled at the gene level . When dietary proteins increase significantly enzyme concentration rise. On return to a balanced diet enzyme levels decline . Under conditions of starvation, enzymes level rise as proteins are degraded and amino acid carbon skeletons are used to provide energy, thus increasing the quantity of nitrogen that must be excreted in the form of urea . 140. Toxic agents present in food which interfere with thyroxine synthesis lead to the development of 1. toxicgoitre 2. cretinism 4 3. simplegoitre 4. thyrotoxicosis Explanation : Simple goitre is caused by deficiency of iodine in diet because iodine is needed for the synthesis of thyroid hormone. Toxic agents present in the food may also interfere with thyroxine (thyroid hormones) synthesis. 141. An important criterion for modern day classification is 4 1. resemblances in morphology 2. anatomical and physiological traits 3. breeding habits 4. presence or absence of notochord Explanation : The given figure is of female thallus of Marchantia (bryophyte) in which a, b, c and d are archegoniophore, female thallus, gemma cup and rhizoids respectively. 142. In which one of the following, the BOD (Biochemical Oxygen Demand ) of sewage (S) ,distillery effluent (DE), paper mill effluent (PE) and sugar mill effluent (SE) have been arranged in ascending order? 1. SE < PE < S < DE 4 2. PE < S < SE < DE 3. S < DE < PE < SE 4. SE < S < PE < DE Explanation : The BOD of the given pollutants in ascending order is PE < S < SE <DE . - 41 - 143. Which one of the following is not a secondary messenger in hormonal action? 1. cAMP 2. cGMP 3. calcium 4 4. sodium Explanation : Secondary messengers are low-weight diffusible molecules that are used to relay signals within a cell. cAMP, cGMP and Ca2+ act as secondary messengers and are located within the cytoplasm. Sodium is an essential nutrient which helps to maintain blood volume and keeps nerves functioning. 144. What was the most significant trend in the evolution of modern man (Homo Sapiens) from his ancestor? 1. Shortening of Jaws 2. Binocular vision 4 3. Increasing cranial capacity 4. Upright posture Explanation : Binocular vision, smaller jaw and upright posture are the main adaptations that led to evolution of man from its ancestors. But during human evolution major and most significant changes occurred in the cranial capacity of man. In Living modern man it is about 1450 cc compared to 500 cc in Australopithecus. Increased cranial capacity accommodates larger brain and forms the basis of social, cultural and educational evolution of modern man. 145. The bacteria (Clostridium botulinum) that causes botulism is 1. an obligate aerobe 2. a facultative anaerobe 4 3. an obligate anaerobe 4. a facultative aerobe Explanation : Clostridium is a genus of Gram positive bacteria. They are obligate anaerobes capable of producing endospores. Individual cells are rod-shaped 146. Middle lamella is composed mainly of 1. muramic acid 4 2. calciumpectate 3. phosphoglycerides 4. hemicellulose - 42 - Explanation : Middle lamella of cell wall is composed of calcium and magnesium pectate. It joins the adjoining cells together and thus acts as a cementing layer. 147. Ovary is half inferior in the flowers of 1. guava 4 2. plum 3. brinjal 4. cucumber Explanation : A flower in which the other floral parts arise from around the ovary is called perigynous. Here ovary is half inferior or half superior. Examples include peach, plum etc. 148. Removal of introns and joining the exons in a defined order in a transcription unit is called 1. tailing 2. transformation 3. capping 4 4. splicing Explanation : mRNA is not made directly in a eukaryotic cell. It is transcribed as heterogeneous nuclear RNA (hnRNA) in the nucleus. hnRNA contains introns and exons. The introns are removed by RNA splicing leaving behind the exons which contain the information. The exonic regions of RNA are joined together to produce a single chain RNA required for functioning as translational template. 149. In arthropoda head and thorax are often used to form cephalothorax. In which one of the following classes is the body divided into head thorax and abdomen? 4 1. Insecta 2. Myriapoda 3. Crustacea 4. Arachnida and Crustacea Explanation : Body in arthropoda is segmented. Segments are grouped into 3 forms – head, thorax and abdomen. When head and thorax are fused then they are referred to as cephalothorax. Class insecta of arthropoda phylum have body dividend into head, thorax and abdomen. - 43 - 150. Some vascular bundles are described as open because these 1. are surrounded by pericycle but no endodermis 4 2. are capable of producing secondary xylem and phloem 3. possess conjunctive tissue between xylem and phloem 4. are not surrounded by pericycle Explanation : In dicot stem cambium is present between xylem and phloem, such vascular bundles are called open. In monocot stem, the cambium is absent and such vascular bundles are called closed. Cambium is a layer of meristematic cells which produces secondary xylem and phloem. 151. In eukaryotic cells, the amount of basic proteins is often found to be 1. more than the amount of DNA 2. less than the amount of DNA 4 3. equal to the amount of DNA 4. none of the above Explanation : The nucleosome consists of approximately equal mass of DNA and histones (including HI). The predicted mass of the nucleosome is 262,000 daltons, with protein/DNA mass ratio of 1:1 152. Parthenogenesis is a term of 4 1. Sexual reproduction 2. Asexual reproduction 3. Budding 4. Regeneration Explanation : Parthenogenes is a form of sexual reproduction in which the ovum develops into a new individual without fertilization. 153. What is the function of germ pore? 1. Emergence of radicle 2. Absorption of water for seed germination 4 3. Initiation of pollen tube 4. Release of male gamete Explanation : After pollination, the pollen grain on the stigma absorbs water and nutrients from the stigmatic secretions through its germ pores. The tube or vegetative cell enlarges and comes out of prollen grains through germ pore to form a pollen tube. - 44 - 154. Best defined function of manganese in green plants is 4 1. photolysis of water 2. Calvin cycle 3. nitrogen fixation 4. water absorption Explanation : Manganese is used for photolysis of water to produce oxygen and electrons during light reaction of photosynthesis. Its acts a an essential cofactor. 155. Alzheimer’s disease in humans is associated with the deficiency of 1. glutamic acid 4 2. acetylcholine 3. gammaaminobutyric acid (GABA) 4. dopamine Explanation : Alzheimer’s disease is a neurological disease characterized by progressive loss of intellectual ability. It is associated with general shrinkage of the brain tissue with deposit of â - amyloid protein and abnormal filaments composed of a protein in the brain and changes in the neurotransmitter systems within the brain that include a loss in the activity of cholinergic neurons (neurons releasing acetylcholine). 156. Maximum number of existing transgenic animals is of 1. fish 4 2. mice 3. cow 4. pig Explanation : Animals that have their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals. Transgenic mice, rabbits, pigs, sheep, cows and fish have been produced, although over 95 percent of all existing transgenic animals are mice. 157. A single strand of nuclei acid tagged with a radioactive molecule is called 1. Vector 2. selectable marker 3. plasmid 4 4. probe Explanation : Probes are single stranded, radio labelled molecules of nucleic acids with known sequences. The probes having sequences complementary to the gene to be identified are supplied. Probes are used as identification tool. - 45 - 158. Which one of the following is categorised as a parasite in true sense? 1. The female Anopheles bites and sucks blood from humans 2. Human foetus developing inside the uterus draws nourishment from the mother 4 3. Head louse living on the human scalp as well as laying eggs on human hair 4. The cuckoo (koel)lays its eggs in crow’s nest Explanation : Parasitism is an association in which one organism (the parasite) lives on (ectoparasitism) or in (endoparasitism) the body of another (the host) from which it obtains its nutrients. They also produce vast number of eggs there e.g , head louse living on the human scalp. 159. A student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colors of light so as to get the best possible resolution? 4 1. Blue 2. Green 3. Yellow 4. Red Explanation : Resolution of microscope is inversely proportional to wavelength of light used. Out of four option given, blue light has minimum wavelength and hence maximum resolution. 160. How many plants in the list given below have marginal placentation? Mustard, Gram, Tulip, Asparagus, Arhar, Sun hemp, Chilli, Colchicum, Onion, Moong, Pea, Tobacco, Lupin. 1. four 2. five 4 3. six 4. Three Explanation : Gram, arhar, sunhemp, moong, pea and lupin belong to family fabaceae which is characterized by marginal placentation. - 46 - 161. A major breakthrough in the studies of cells came with the development of electron microscope. This is because 1. A major breakthrough in the studies of cells came with the development of electron microscope. This is because 4 2. the resolving power of the electron microscope is much higher than that of the light microscope 3. the resolving power of the electron microscope is 200 -350 nm as compared to 0.1 -0.2 nm for the light microscope 4. electron beam can pass through thick materials, where as light microscope requires thin sections Explanation : In electron microscopes, a high energy beam of electrons is focused through electromagnetic lenses. It can magnify very small details with high resolving power. The increased resolution results from the shorter wavelength of the electron beam. 162. Photosynthetically Active Radiation (PAR) has the following range of wavelengths. 1. 340 – 450 nm 4 2. 400 – 700 nm 3. 500 – 600 nm 4. 450 – 950 nm Explanation : Wavelengths between 400 and 700 nm comprise the visible range of electromagnetic spectrum and are capable of causing photosynthesis. These are called photosynthetically active radiations. 163. The letter T in T-lymphocyte refers to 1. thalamus 2. tonsil 4 3. thymus 4. thyroid Explanation : The immature lymphocytes originate in bone marrow. Then these lymphocytes migrate via blood to the thymus. Once these cell center the thymus they are called as the thymocytes and mature as T-lymphocytes (T cells). - 47 - 164. Which one of the following is a wrong matching of microbe and its industrial product,while the remaining three are correct? 1. Yeast -statins 2. Acetobacteraceti – acetic acid 4 3. Clostridium butylicum -lactic acid 4. Aspergillusniger -citric acid Explanation : Microbes are used for commercial and industrial production of certain chemicals like organic acids, alcohols and enzymes. Example of acid producers are Aspergillusniger (a fungus) of citric acid, Acetobacteraceti (a bacterium) of acetic acid; Clostridium butylicum (a bacterium) of butyric acid and Lactobacillus (a bacterium) of lactic acid . 165. Parthenocarpic tomato fruits can be produced by 1. treating the plants with phenylmercuric acetate 2. removing androecium of flower before pollen grains are released 4 3. treating the plants with low concentration of gibberellic acid and auxins 4. raising the plants from vernalized seeds Explanation : Development of fruits without fertilizers is called parthenocarpy and such fruits are called parthenocarpic fruits. For parthenocraphy induction by auxin , these should be applied after anthesis (first opening of flower) and by gibberellins , these should be applied earlier at anthesis. 166. What type of placentation is seen in sweet pea? 4 1. marginal 2. basal 3. axile 4. free central Explanation : The arrangement of ovules inside the ovary on placenta is called placentation. Sweet pea or Lathyrusodoratus belongs to family leguminosae or fabaceae and in all the members of this family the placentation is marginal in which ovary is unilocular and ovules are borne on margin. 167. Fastest distribution of some injectible material / medicine and with no risk of any kind can be achieved by injecting it into the 1. muscles 2. arteries 4 3. veins 4. lymph vessels - 48 - Explanation : Intravenous injection is given for rapid distribution of drugs / substances. Intra -muscular injection is given for producing local effect. 168. Consider the following four statement (1-4) about certain desert animals such as kangaroo rat. Which one is true? 1. They have dark color and high rate of reproduction and excrete solid urine 2. They do not drink water , breathe at a slow rate to conserve water and have their body covered with thick hairs 4 3. They feed on dry seeds and do not require drinking water 4. They excrete very concentrated urine and do not use water to regulate body temperature Explanation : Kangaroo rat feeds on dry seeds. It seldom drinks water. The requirement of water is met by food (10%) and (90%). Water loss is prevented by living in burrows during the day, concentration of urine and solidification of faeces. It has a thick coat to minimise evaporative desiccation. 169. Which one of the following pairs of food components in humans reaches the stomach totally undigested? 1. starch and fat 2. fat and cellulose 4 3. starch and cellulose 4. protein and starch Explanation : Saliva contains no lipase. The stomach also lacks any fat – emulsifying agents. Fat is largely digested in the small intestine. Cellulose is not digested in human beings. 170. A nitrogen-fixing microbe associated with Azolla in rice fields is 1. Spirulina 4 2. Anabaena 3. Frankia 4. Tolypothrix Explanation : Azolla plays a very important role in rice production. Azolla and its nitrogen – fixing partner Anabaena have been used as green manure to fertilize rice paddies and increase production. - 49 - 171. What is true about Bt toxin? 1. Bt protein exists as active toxin in the Bacillus 2. The activated toxin enters the ovaries of the pest to sterilise it and thus prevent its multiplication 3. The concerned Bacillus has antitoxins 4 4. The inactive protoxin gets converted into active form in the insect gut Explanation : The cry gene of Bacillus thuringiensis produces Bt protein which forms crystalline inclusion in the bacterial spores. The crystal proteins are inactive (protoxins) in the bacterial body but when they enter in the insect gut, they convert into active form due to the alkaline pH of the alimentary canal that solubilize the crystals. The activated toxin binds to the surface of midgut epithelial cells and creates pores which cause cell swelling and lysis and finally cause death of insect. 172. Which is the mojor hot spot in India? 1. Aravalli hills 4 2. Western ghats 3. Indo-gangetic plain 4. Eastern ghats Explanation : Hot-spot are areas with high density of biodiversity or megadiversity and are also the most threatened ones. Hot spots are determined by four factors-Number of species / species diversity, Degree of endemism, Degree of threat to habitat due to its degradation and fragmentation, Degree of exploitation. 173. Which one of the following enzymes carries out the initial step in the digestion of milk in human? 4 1. pepsin 2. rennin 3. lipase 4. trypsin Explanation : Pepsin is an enzyme that breaks down proteins into smaller peptides (that is, a protease). It is produced in the stomach and is one of the main digestive enzymes in the digestive systems of humans and many other animals, where it helps digest the proteins in food. - 50 - 174. Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on 1. membrane potential 2. accumulation of Na+ ions 3. accumulation of K+ ions 4 4. proton gradient Explanation : Chemiosmotic coupling hypothesis is the most widely accepted explanation for oxidative phosphorylation in mitochondria and photophosphorylation in thylakoid membranes . Mitchell suggested that a concentration gradient of protons is established across the mitochondrial membrane because there is an accumulation of hydrogen ions on side of the mitochondrial membrane. The proton accumulation is necessary for energy transfer to the endergonic ADP phosphorylation process. 175. A plant requires magnesium for 1. protein synthesis 4 2. chlorophyll synthesis 3. cell wall development 4. holding cells together Explanation : Magnesium is an important constituent of chlorophyll, found in all green plants and essential for photosynthesis. The chlorophyll molecules has a tetrapyrrolic or porphyrin head and a phytol tail. Mg atom is present in the center of porphyrin head. 176. Which one of the following is common to multicellular fungi, filamentous algae and protonema of mosses? 1. Diplontic life cycle 2. Members of kingdom plantae 3. Mode of nutrition 4 4. Multiplication by Fragmentation Explanation : Algae and moss are included in plant kingdom while fungi constitute a separate kingdom. Among them mosses invariably show diplontic life cycle while other may or may not. Algae and moss are autotrophic while fungi are heterotrophs. But they all show multiplication by fragmentation. 177. Virus envelope is known as 4 1. capsid 2. virion 3. nucleoprotein 4. core - 51 - Explanation : The nucleic acid of a virus is surrounded by a protein coat called the capsid. The capsid is composed of protein subunits called capsomeres. In some viruses the capsid is covered by an envelope which usually consists of some combination of lipids , proteins and carbohydrates. 178. Ringworm in humans is caused by 1. bacteria 4 2. fungi 3. nematodes 4. viruses Explanation : Ringworm (tinea) is a fungal infection of the skin, scalp or nails. Ringworm is caused by the dermatophyte fungi species of Microsporum,Trichophyton and Epidermophyton. It can be spread by direct contact or via infected materials. The lesions of ringworm may form partial or complete rings and may cause intense itching. 179 Monascuspurpureus is a yeast used commercially in the producing of 1. ethanol 2. streptokinase for removing clots from the blood vessels 3. citric acid 4 4. blood cholesterol lowering statins Explanation : Statins are produced by the yeast Monascuspurpureus which have been commercialized as blood -cholesterol lowering agents. It act by competitively inhibiting the enzymes responsible for synthesis of cholesterol. 180. Which one of the following techniques is safest for the detection of cancers? 4 1. Magnetic resonance imaging (MRI) 2. Radiography (X-ray) 3. Computed tomography (CT) 4. Histopathological studies Explanation : Histopathological study is the invasive technique, Radiography and CT involves X-rays which are harmful. In MRI, strong magnetic fields and non -ionising radiations are used to detect any physiological changes in the using tissues.
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