Test-4 (Code-A)_(Answers) All India Aakash Test Series for NEET-2020
All India Aakash Test Series for NEET - 2020
TEST - 4 (Code-A)
Test Date : 08/12/2019
ANSWERS 1. (2) 37. (1) 73. (3) 109. (2) 145. (4) 2. (3) 38. (1) 74. (1) 110. (4) 146. (2) 3. (4) 39. (3) 75. (4) 111. (3) 147. (1) 4. (1) 40. (1) 76. (1) 112. (1) 148. (2) 5. (3) 41. (3) 77. (2) 113. (3) 149. (3) 6. (2) 42. (2) 78. (3) 114. (4) 150. (3) 7. (1) 43. (2) 79. (2) 115. (3) 151. (3) 8. (2) 44. (1) 80. (2) 116. (2) 152. (4) 9. (4) 45. (2) 81. (2) 117. (4) 153. (2) 10. (3) 46. (4) 82. (1) 118. (2) 154. (3) 11. (1) 47. (2) 83. (3) 119. (3) 155. (4) 12. (3) 48. (4) 84. (1) 120. (4) 156. (2) 13. (2) 49. (4) 85. (2) 121. (2) 157. (3) 14. (1) 50. (4) 86. (1) 122. (1) 158. (2) 15. (3) 51. (4) 87. (4) 123. (4) 159. (1) 16. (1) 52. (1) 88. (3) 124. (3) 160. (2) 17. (4) 53. (4) 89. (3) 125. (2) 161. (1) 18. (3) 54. (3) 90. (1) 126. (1) 162. (1) 19. (3) 55. (2) 91. (3) 127. (3) 163. (4) 20. (2) 56. (2) 92. (2) 128. (3) 164. (4) 21. (3) 57. (2) 93. (1) 129. (2) 165. (2) 22. (1) 58. (4) 94. (4) 130. (4) 166. (2) 23. (2) 59. (2) 95. (3) 131. (2) 167. (3) 24. (3) 60. (3) 96. (2) 132. (3) 168. (2) 25. (1) 61. (4) 97. (2) 133. (2) 169. (2) 26. (2) 62. (4) 98. (4) 134. (4) 170. (4) 27. (3) 63. (1) 99. (3) 135. (3) 171. (4) 28. (4) 64. (4) 100. (3) 136. (3) 172. (3) 29. (4) 65. (3) 101. (4) 137. (4) 173. (1) 30. (3) 66. (1) 102. (2) 138. (1) 174. (3) 31. (4) 67. (3) 103. (2) 139. (1) 175. (1) 32. (4) 68. (2) 104. (4) 140. (4) 176. (3) 33. (3) 69. (3) 105. (1) 141. (3) 177. (4) 34. (1) 70. (3) 106. (3) 142. (1) 178. (4) 35. (1) 71. (3) 107. (1) 143. (1) 179. (4) 36. (3) 72. (2) 108. (3) 144. (3) 180. (3)
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1/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
HINTS & SOLUTIONS [PHYSICS] 1. Answer (2) Sol. : Hint and Sol. : Light of all wavelengths in vacuum 1 Case - I : h mv2 ...(i) travel with same speed, so 2 1 c ° 1 Case - II : 4h mv 2 ...(ii) 2. Answer (3) 2 2 E Divide (i) by (ii) Hint : Momentum of photon p 2 c h mv1 2 2 Sol. : Energy of photon = 3 MeV 4h mv2 2 = 3 × 1.6 × 10–13 joule 2 2 4mv1 8 mv 2 2 E 3 1.6 1013 p 2 2 6 8 v4 v c 3 10 2 1 m –21 p = 1.6 × 10 kg m/s v2 2 v 1 3. Answer (4) 6 Answer (2)
Hint : Energy of photon = 0 + eV0 Hint : Kinetic energy of charged particle = qV h h Sol. : Work function of surface = 5.1 eV Sol. : de-Broglie wavelength Energy of incident photons = (5.1 + 6) eV p 2 mK
= 11.1 eV 2 h For deuteron (H)1 D 12400 2qV (2 m) Wavelength of photons = Å 11.1 4 h For -particle (2 He ) 1117 Å 2(2q ) V (4 m) Wavelength 1117 Å lies in ultraviolet region. 2 D 4. Answer (1) 1 Hint : Maximum kinetic energy of photo electron 7. Answer (1) Hint and Sol. : Point source is placed at focus of = eVC convex lens, so after refraction light rays become Sol. : Work function of surface = h0 parallel. Hence on changing the distance, there is no change in number of photons striking on 6.6 1034 5 10 14 photocell. So saturated current and cut-off potential 1.6 1019 remains same. = 2.06 eV 8. Answer (2) Wavelength of incident radiation = 4000 Å Hint and Sol. : Stopping potential is greater for b than a it means > . Saturation photo current is 12400 b a Energy of incident radiation = = 3.1eV same for a and b it means I = I 4000 a b 9. Answer (4) Energy of photon = + eV c Hint and Sol. : One of the electrons enters in 3.1 = 2.06 + eVc magnetic field, so there is no change in magnitude of linear momentum. Hence remains same. While eVc = 1.04 eV 1 second electron enters in electric field, and it will V = 1.0 V c accelerate, so its magnitude of momentum may 5. Answer (3) increase, decrease or at some instant may be equal
1 to the first electron. Hence 1 may be greater than Hint : h mv2 2 equal or less than 2. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
2/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
10. Answer (3) 15. Answer (3) Hint : In electric fields particle will accelerate so its Hint : The radius of Bohr orbit of hydrogen like momentum will change. 2 n element is rn 0.529 Å Sol. : Electric force on charge F qEi Z qE Sol. : Radius of first orbit of hydrogen Acceleration of charge a i m r1 = 0.529 Å Velocity along x-axis vx (as a function of time) Radius of second orbit of helium ion qE 0.529 4 t r Å m 2 2 h h = 1.058 Å 3mv 2 2 –11 0 ()()mv0 qEt = 10.58 × 10 m 2 2 2 2 2 2 2 16. Answer (1) 9m v0 = m v0 + q E t 2 2 2 2 2 Z 8m v0 = q E t Hint : Speed of electron in any orbit v n n 2 2mv t 0 2 qE n Radius of Bohr orbit rn 11. Answer (1) Z Hint : Einstein’s equation of photoelectric effect. Sol. : vn = rnn
hc n 1 Sol. : eV0 w vn r n hc Case - I : 3eV0 w ...(i) n 1 2 vn n hc Case - II : eV w ...(ii) 17. Answer (4) 0 2 Hint and Sol. : Wavelength of first line of Balmer Multiply equation (ii) with 3 and subtract equation (i) series. hc hc 2w 0 2 w 1 1 1 2 2 R 22 3 2 hc hc B 2 1 1 5R 0 2 R 4 9 36 0 = 4 Wavelength of second line of lyman series. 12. Answer (3) Hint : Total energy of electron in any orbit is half of 1 1 1 8R R potential energy. L 1 9 9 1 Ze2 Sol. : Total energy of electron B 32 ETot 40 2rn L 5 2 1 Ze 18. Answer (3) Potential energy of electron EPot 40 rn Hint and Sol. : Average mass density EPot : ETot = 2 : 1 M Am d P 13. Answer (2) V 4 3 R Hint and Sol. : Absorption of energy is possible only 3 from ground state n = 1. So in absorption spectrum 1 possible spectral lines are 3. RRA 3 14. Answer (1) 0 Hint and Sol. : Intensity of x-rays depends on 3Am d P number of photons, which depends on number of 3 4RA0 electrons striking at target. The number of electrons can be increased by increasing current in filament. d A° Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
3/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
19. Answer (3) 25. Answer (1)
Hint and Sol. : Hint : Mean life = 1.44 T1/2 50 N Sol. : Initial value 50% NN 0 0100 0 2 3.125 N Remaining value 3.125% NN 0 0100 0 32 n 1 NN 0 2 n -particle of all the energies from 0 to a certain NN 1 maximum value emitted from same element. So 0 0 32 2 2 spectrum is continuous spectrum. 4 n 20. Answer (2) 1 1 Hint and Sol. : Nuclear forces between two 2 2 nucleons having like spin is different than those 40 having unlike spin, so nuclear forces are spin Half life of element 10 s dependent. 4 21. Answer (3) Mean life = 10 × 1.44 = 14.4 s 26. Answer (2) 1 Hint and Sol. : 1 atomic mass unit [mass of Hint and Sol. : Concentration of holes is greater 12 12 than number of free electrons, so it is a P-type one 6C carbon atom]. semiconductor. 22. Answer (1) 27. Answer (3) Hint : In this process momentum remains constant. Hint and Sol. : As doping concentration increased Sol. : According to law of conservation of width of depletion layer decreases. momentum 28. Answer (4) 0 m1 v 1 m 2 v 2 Hint and Sol. : A zener diode is highly doped and used in reverse biased. 0 = m1v – m2 (27v) 29. Answer (4) m 27 1 Hint and Sol. : Extrinsic semiconductors are also m2 1 electrically neutral because they contain equal 4 number of acceptors and donors. R3 1 27 30. Answer (3) 3 4 Hint and Sol. : In reverse bias the barrier potential R3 1 3 2 (V0 + Vr) becomes large. Therefore, the diffusion current is usually negligible for reverse bias. R : R = 3 : 1 1 2 31. Answer (4) 23. Answer (2) Hint and Sol. : In forward biases P-type is at high Hint : Energy will be released in nuclear reaction, potential and n-type at low potential so diode in when energy of product nuclei is greater than the option (4) is forward biased. energy of reactant nuclei 32. Answer (4) Sol. : Energy of product nuclei = 4c Hint and Sol. : Truth table of given circuit Energy of reactant nuclei = (a + 3b) A B Y Energy released = 4c – (a + 3b) 0 0 1 = 4c – a – 3b 24. Answer (3) 1 0 1 Hint and Sol. : As the mass of radioactive sample 0 1 1 is increased, then number of nuclei will also 1 1 0 increase, so activity will increase. Decay constant is the property of element, so it remains same. The given truth table is for NAND gate.
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4/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
33. Answer (3) 8.64 1012 n 3.375 1023 R 11 Hint : Power gain P 2 L 3.2 0.8 10 R in 235 3.375 1023 Mass of uranium 2 2000 6.023 1023 Sol. : P (5) 5000 10 = 132 g (app.) 34. Answer (1) 38. Answer (1) Hint : When amplifiers are connected in series Hint and Sol. : then resultant voltage gain A = A1 × A2. Potential drop in D2 = 0.7 V Sol. : Net voltage gain A = 20 × 20 = 400 35. Answer (1) Hint and Sol. : Truth table of NOR gate.
ABYY 0 0 0 1 0.7 1 0 1 0 0.2 mA Current in 3.5 k 3 0 1 1 0 3.5 10 1 1 1 0 39. Answer (3) Hint and Sol. : In common emitter amplifier input 36. Answer (3) and output voltage are in opposite phase. Hint : The rate of disintegration of x is more than 1 V A out x2. Vin 10 t Sol. : Nx N0 e 1 Vout = 0.04 × 100 = 4 V N N et 3 x2 0 V(4 V)sin t 10 t 2 Nx e 1 40. Answer (1) N et x2 Hint : Current will flow in junction diode when it is 1 forward biased. e9 t e3 Sol. : If P is at low potential and Q at high potential, then no diode will conduct, so 1 1 RPQ = 4 e3 e 9t e9t = e3 9t = 3 1 t 3 37. Answer (1) Hint and Sol. : Energy released per fission = 200 MeV –11 = 3.2 × 10 J 41. Answer (3) Total energy produced per day Hint and Sol. : Diode is in forward bias, hence 6 = 100 × 10 × 86400 (3 1) = 8.64 × 1012 J I 20 mA 100 Number of fission per day = n 42. Answer (2) Efficiency of reactor = 80% Hint : Zener diode will conduct when potential 80 n × 3.2 × 10–11 × 8.64 1012 difference across zener is more than break down 100 voltage. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
5/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
ABY 0 0 1 Sol. : 1 0 0 0 1 0 1 1 0
Potential drop across dropping resistance = 20 V It is a NOR gate 20 Current in dropping resistance i 40 mA 44. Answer (1) 500 Hint : During decay mass number decrease by 4 10 Current in 1 k, i 10 mA and no change in mass number during decay. 1 1000 Current in zener diode = (40 – 10) mA Sol. : 4 × n = 32 = 30 mA n = 8 43. Answer (2) and 6 Hint and Sol. : 45. Answer (2) Hint and Sol. : Base in transistor is lightly doped and thin.
[CHEMISTRY] 46. Answer (4) Sol. :
Hint : N-Ethylbenzamide is Sol. :
49. Answer (4)
47. Answer (2) Hint : Hint :
50. Answer (4)
Sol. : Hint : Carboxylic acid is a stronger acid than carbonic acid.
Sol. :
48. Answer (4) Hint : Nylon 6 is a polyamide D reacts with NaHCO3 to release CO2 Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
6/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
51. Answer (4) 57. Answer (2) Hint : Cinnamaldehyde is an , unsaturated Hint : aromatic aldehyde. Artificial sweetener Sweetness value in Comparison to cane sugar Aspartame 100 52. Answer (1) Saccharin 550 Hint : Homopolymers consist of only one type of Sucralose 600 monomeric species Alitame 2000 Sol. : 58. Answer (4) Polymer Monomer Hint : Xerophthalmia is the hardening of cornea of eye. PVC Vinyl chloride Sol. : This happens due to the deficiency of Teflon Tetrafluoroethene vitamin A. Neoprene 2-chloro-1,3-butadiene 59. Answer (2) 53. Answer (4) Hint : Hint : Polypropene is used in the manufacture of ropes. Benzenamine is Sol. : Polystyrene is used as insulator. Urea-formaldehyde resin is used for making Sol. : Order of basic character : unbreakable cups and laminated sheets. Bakelite (Polymer of phenol and formaldehyde) is used for making electrical switches) 60. Answer (3) 54. Answer (3) Hint : In maltose, C-1 of one -D-Glucopyranose is Hint : Compounds in which carbonyl group is least linked to C-4 of another -D-Glucopyranose hindered are found to be most reactive towards molecule by glycosidic linkage. nucleophilic addition reaction. Sol. : Sol. : Carbonyl group in formaldehyde is least hindered. 55. Answer (2)
Hint : CrO2Cl2 can be used to oxidise toluene to benzaldehyde.
Sol. : 61. Answer (4) Hint : D-ribose is in furanose form Sol. :
56. Answer (2) Hint : PCC is a mild oxidising agent.
Sol. : 62. Answer (4) PCC Hint : PHBV and Nylon-2-Nylon 6 are biodegradable CH3 CH 2 CH 2 CH 2 OH CH 3 CH 2 CH 2 CHO Butanal polymer. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
7/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
63. Answer (1) 70. Answer (3) Hint : Tranquilizers relieve or reduce the stress and Hint : Lower aliphatic amines are more soluble in anxiety. water than higher aliphatic amines. Sol. : Tranquilizers : Equanil, Phenelzine Sol. : Solubility of amines in water decreases with 64. Answer (4) increase in molar mass of amines due to increase Hint : An elastomer involves weakest van der Waals in size of the hydrophobic alkyl part. interactions. 71. Answer (3) Sol. : Buna–N is an elastomer Hint : 65. Answer (3) Hint : Hinsberg’s reagent is
reacts with Br2 water, NH2OH, HCN
Sol. : reacts with acetic anhydride Sol. :
2°-amine CH3NHCH3 reacts with Hinsberg’s 66. Answer (1) reagent (or, benzenesulphonyl chloride). Hint : Essential amino acids cannot be synthesised 72. Answer (2) in the body. O Sol. : Essential amino acids : Histidine
67. Answer (3) Hint : Acrolein is H — C— CH CH2 Hint : Albumin is a globular protein. Sol. : Sol. : Globular proteins are usually soluble in water. 68. Answer (2) Hint : O
Acetamide is CH3 — C— NH 2
Sol. : 73. Answer (3) CH3 COOH NH 3 CH 3 COO NH 4 HO2 Hint : O CH3 — C— NH 2 Acetanilide is 69. Answer (3) Hint : Benzene diazonium chloride reacts with Sol. : phenol and aniline in basic and acidic medium respectively. Sol. :
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8/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
74. Answer (1) 80. Answer (2)
Hint : Cyanide group (CN) is reduced into Hint : Et—Br undergoes SN2 reaction in Gabriel – CH2NH2 phthalimide synthesis of 1° amines. Sol. : Sol. :
75. Answer (4) Hint : Carboxylic acids are generally stronger acid than alcohols and phenols. Sol. :
76. Answer (1) Hint : Lone pairs of N2 and N3 are involve in resonance with keto group. 81. Answer (2) Hint : During cannizzaro reaction, disproportionation of aldehydes takes place with conc. NaOH. Sol. : Sol. : Aldehydes which do not have an -hydrogen atom, undergo oxidation and reduction (disproportionation) reaction on heating with concentrated NaOH or KOH. 77. Answer (2) For example : Formaldehyde, benzaldehyde. Hint : Nitrile on complete hydrolysis, gives 82. Answer (1) carboxylic acids. Hint : Nitrobenzene gives different products in Sol. : alkaline medium under different conditions. Sol. :
78. Answer (3) Hint : Cleavage of > C = C < take palce
Sol. : 83. Answer (3) Hint : This is an example of Iodoform test. Sol. : 79. Answer (2) Hint : B·P· of carboxylic acid is more than that of aldehydes with comparable molecular mass. Sol. : Formic acid exists as dimer in the vapour phase. Benzoic acid is nearly insoluble in cold water due to larger size of its hydrophobic ring. Acetic acid is miscible in water.
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9/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
84. Answer (1) 88. Answer (3) Hint : Hint : Low density polythene is used in the insulation of electricity carrying wires. 89. Answer (3)
Sol. : Formaldehyde gives positive Tollens’ test. Hint : C2H4O is an aldehyde. 85. Answer (2) Sol. : Hint : Given carbohydrate is sucrose Sol. : Sucrose consists of -D-glucose and -D- fructose 86. Answer (1) Hint : DNA contains four bases : A, G, C, T 90. Answer (1) Sol. : DNA does not contain uracil (U) Hint : Partial reduction take place 87. Answer (4) Hint : Ester is reduced into aldehyde by using Sol. : DIBAL – H (i) DIBAL H in toluene CH(CH)COOCH CH(CH)CHO 3 2 9 2 5 3 2 9 (ii) H3 O [BIOLOGY] 91. Answer (3) 95. Answer (3) Hint : Net primary productivity is the rate of organic Hint : In a food chain, transfer of energy at different matter build up or stored by producers in excess of trophic levels occur according to “10% law of energy respiratory utilization. transfer”. Sol. : Net primary productivity (NPP) is the Sol. : If NPP is 2000 J then fixed energy in available biomass for the consumption of herbivores (primary consumer) is 200 J, secondary heterotrophs i.e. herbivores and decomposers. It consumers 20 J, tertiary consumers 2 J. depends upon various environmental factors. NPP of terrestrial ecosystems is generally higher than 96. Answer (2) ocean. Hint : Plants capture approximately 1-5% of 92. Answer (2) incident solar radiation for photosynthesis. Hint : Decomposition process is slower when Sol. : Plants capture 2-10% of PAR for detritus contains complex and water-insoluble synthesising their food. compounds. 97. Answer (2) Sol. : Decomposition of detritus containing lignin, chitin and cellulose is slower. Process of Sol. : Ecological pyramids accommodate a simple decomposition requires aeration, activity of soil food chain not a food web. Saprophytes, microbes, warm and moist soil. decomposers and microbes are not given any place in ecological pyramid. 93. Answer (1) Hint : Stratification is vertical distribution of 98. Answer (4) different species occupying different levels. Sol. : During succession, total biomass of the Sol. : In a forest, vertical subdivision or strata are ecosystem increases. a. Trees – Top layer 99. Answer (3) b. Shrubs – Second layer Sol. : For tree ecosystem, pyramid of number c. Grasses and herbs – Bottom layer could be inverted or spindle shaped. 94. Answer (4) 100. Answer (3) Sol. : Detritus food chain begins with detritus or Hint : Anthropogenic ecosystems are created and dead organic matter. maintained by humans.
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10/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
Sol. : Characteristics of anthropogenic ecosystem 109. Answer (2) a. Low species diversity. Hint : Among the invertebrates, insects are the b. High productivity. most species rich. c. Presence of simple food chain. Sol. : In the given pie chart d. Absence of self regulatory mechanisms. A – Insects e. Little cycling of nutrients. B – Molluscs 101. Answer (4) C – Crustaceans Hint : In secondary succession, pioneer 110. Answer (4) community establishes with comparatively more Hint. : Biodiversity is important for ecosystem ease. stability, productivity, resistance etc. Sol. : Secondary succession starts in areas that Sol. : Communities with more biodiversity are somehow lost all the living organisms that existed more stable and more resistant to natural there. It has some soil or sediment existing at the disturbances, man-made disturbances and invasion site of succession. Here climax is also reached more by alien species. Rich biodiversity decreases year- quickly. to-year variations in productivity of an ecosystem. 102. Answer (2) 111. Answer (3) Hint : In hydrarch succession, the successional Sol. : Some examples of most recent extinctions series progress from hydric to mesic conditions. are Sol. : Transitional communities in hydrarch Dodo – Mauritius succession are – Quagga – Africa Submerged plant stage Submerged free-floating Thylacine – Australia plant stage Reed-swamp stage Marsh- Steller’s sea cow – Russia meadow stage Scrub stage. 112. Answer (1) 103. Answer (2) Sol. : Cichlid fishes of Lake Victoria of East Africa Hint : Part of water soluble substances present in are the native species of that area. fragmented and decomposing detritus go down in 113. Answer (3) soil horizon by percolating water is called leaching. Hint : Species with small population are more Sol. : During decomposition, fragmentation of susceptible to extinction. detritus involves activity of detrivores while Sol. : Large body size, low reproductive rate, high humification and mineralisation involve activity of trophic level in food chain, fixed habitat and saprophytic fungi and bacteria. Leaching process migratory route are some characteristics of those does not directly involve activity of living organisms. species which are highly susceptible to extinction. 104. Answer (4) 114. Answer (4) Sol. : Reservoir pool of a gaseous cycle is Hint : in-situ conservation strategies are also atmosphere or hydrosphere. Lithosphere or earth’s called on-site conservation strategies. crust is the reservoir pool for sedimentary cycle. Sol. : Hot-spots, national parks, sacred lakes and 105. Answer (1) biosphere reserves are in-situ conservation Hint : Phosphorus cycle is a sedimentary cycle. strategies. Sol. : There is no respiratory release of 115. Answer (3) phosphorus into atmosphere by living organisms. Hint : Direct economic benefits derived from nature 106. Answer (3) are called narrowly utilitarian benefits. Sol. : Humus is dark coloured, amorphous, more Sol. : Pollination, oxygen and aesthetic pleasure or less decomposed organic matter. It is slightly are broadly utilitarian benefits of ecosystem. Rest acidic and resistant to microbial action. are narrow utilitarian benefits. 107. Answer (1) 116. Answer (2) th Hint : India is on 8 rank among 12 megadiversity Hint : Rivet popper hypothesis was given by Paul countries. Ehrlich which explains relation between biodiversity Sol. : India has only 2.4% of world’s land area but and ecosystem health. it possesses 8.1% species diversity of the world. Sol. : According to Rivet popper hypothesis, loss 108. Answer (3) of key species is major threat to ecosystem safety Sol. : Species area relationship of biodiversity was because key species drive major ecosystem given by Alexander von Humboldt. functions. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
11/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
117. Answer (4) Sol. : EcoSan toilets are hygienic, cost-effective Sol. : Khasi and Jaintia hills are situated in and efficient solution of human waste disposal. Meghalaya. 127. Answer (3) 118. Answer (2) Hint : Global warming leads to melting of polar ice Sol. : Snow leopards are protected in caps. Khangchendzonga National park of Gangtok, Sol. : Global warming causes melting of polar ice Sikkim. caps and rise in sea level. 119. Answer (3) 128. Answer (3) Hint : Trees such as Neem and Ashoka are Hint : Ozone depletion can cause UV radiation planted under green muffler scheme to reduce noise mediated damages to humans. pollution. Sol. : If ozone depletion occurs, UV radiation Sol. : specially UV-B can cause DNA damage, mutations, Removal of particulate matter – Electrostatic skin cancer, ageing of skin, damage to cornea and snow blindness. precipitator. CO fertilisation effect and cooling of troposphere Controls SO pollution – Scrubber 2 2 are associated with greenhouse effect. Hospital waste disposal – Incinerators 129. Answer (2) 120. Answer (4) Hint : Polyblend mixed with bitumen is used to lay Sol. : Ozone (O3) is a secondary air pollutant. roads. 121. Answer (2) Sol. : Polyblend is a fine powder of modified Hint : High sulphur content in petrol or diesel recycled plastic developed by Ahmed Khan.
increases SO2 pollution. 130. Answer (4) Sol. : One of the important measures taken by the Sol. : Painful skeletal deformities or itai-itai is due government to reduce air pollution is, use of low- to cadmium toxicity. sulphur petrol or diesel. 131. Answer (2) 122. Answer (1) Hint : This area is at the south pole of earth. Hint : In the 3rd session of conference of parties a Sol. : Every year between late August and early protocol was proposed for countries to take October ozone hole is observed over the Antarctic appropriate measure to reduce overall levels of region. greenhouse gas emission. 132. Answer (3) Sol. : 3rd session of conference of parties (COP) Hint : Jhum cultivation is slash and burnt was held in Kyoto, Japan was an important initiative agricultural practice used in north-eastern states of to take measures towards global climate change. India. 123. Answer (4) Sol. : Jhum cultivation leads to deforestation while Sol. : In Bhopal gas tragedy, the poisonous gas Van Mahotsava, Chipko movement and Joint forest Methyl isocynate (MIC) was leaked. management are associated with maintenance and conservation of forests. 124. Answer (3) 133. Answer (2) Hint : Biochemical oxygen demand (BOD) is a measure of oxygen required by aerobic Sol. : Ramesh Chandra Dagar is related to organic decomposers for degradation of organic waste farming in Haryana, India. material in water. 134. Answer (4) Sol. : Increase in amount of biodegradable organic Hint : Water hyacinth (Eichhornia crassipes) is wastes in water increases BOD and leads to low called terror of Bengal. amount of dissolve oxygen. Sol. : Water hyacinth is an invasive problematic 125. Answer (2) aquatic weed of eutrophic lakes. Sol. : High concentration of DDT causes thinning 135. Answer (3) of egg shells and their premature breaking by Hint : All the buses of Delhi were shifted to CNG by disturbing calcium metabolism. year 2002 by the government. 126. Answer (1) Sol. : CNG burns more efficiently than petrol and Hint : Ecosanitation uses dry composting toilets to diesel. It cannot be adulterated like petrol and recycle human excreta into natural fertilizers. diesel. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
12/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
136. Answer (3) 143. Answer (1) Hint : Stealing of patent. Hint : pBR322 has unique restriction site for certain Sol. : Biopiracy is the term used to refers to the use endonucleases. of bio-resources by multinational companies and Sol. : Unique restriction site for Sal I is present in other organisations without proper authorisation tetra cycline resistance gene. from the countries and people concerned with 144. Answer (3) compensatory payment. Hint : Selectable marker helps in eliminating the 137. Answer (4) non-transformants. Hint : Identify a super bug. Sol. : Purified DNA precipitates out after the Sol. : Bioremediation is a strategy that uses addition of chilled ethanol. Plasmids are naturally occurring organisms to breakdown extrachromosomal double stranded circular DNA in pollutants, such as petroleum hydrocarbons bacteria. into less toxic substances. Bioremediation by 145. Answer (4) Pseudomonas aeruginosa is also well documented. Hint : Origin of replication. 138. Answer (1) Sol. : Plasmids are extra-chromosomal DNA. They Hint : It is considered as salt retaining hormone replicate autonomously and are one of the most Sol. : The gene for human growth hormone (hGH) commonly used cloning vectors. was isolated from human pituitary gland. E. coli is 146. Answer (2) used in recombinant DNA technology for Hint : Extraction of desired product utilizes pharmaceutical manufacturing of insulin. downstream processing. 139. Answer (1) Sol. : Downstream processing is the name given to Hint : It is produced by Streptococcus. the stage after fermentation when the desired Sol. : Myocardial infarction can now be treated by product is recovered and purified. genetic engineering. Erythropoietin is synthesized 147. Answer (1) from J.G. cells of kidney promoting erythropoiesis. Hint : Bacterial cells must be made ‘competent’ to Interleukins are lymphokines that activate immune take up DNA. system. Sol. : Other methods for insertion of recombinant 140. Answer (4) DNA into the host cell/organism include Hint : Breaking dsDNA into ssDNA is DNA microinjection, biolistic etc. denaturation. 148. Answer (2) Hint : It is genetic material of Reoviruses Sol. : The temperature of melting (Tm) or denaturation is defined as the temperature at which Sol. : In nature, RNA is used for the regulation of 50% of double stranded DNA is changed to a single- specific genes and is also applied as a defence stranded DNA. The process of breaking the against pathogens. hydrogen bonds between the nucleotide base pairs 149. Answer (3) in double stranded DNA requires energy. Hint : Organisms belonging to largest phylum. 141. Answer (3) Sol. : Baculoviruses are insect pathogenic viruses Hint : They are called molecular glue. that are used for insect control and as tools to Sol. : DNA ligases form phosphodiester bonds produce recombinant proteins. They are particularly between adjacent nucleotides and covalently link valuable where traditional chemical insecticides two individual fragments of double-stranded DNA by have become ineffective. utilising energy from dNTPs. Endonucleases are 150. Answer (3) restriction enzymes. DNA polymerase synthesizes a Hint : Transformed cell may turn into a tumor. new strand of DNA complementary to an existing Sol. : Agrobacterium tumefaciens invades plants DNA template in 5 to 3 direction. at the site of wound and delivers T-DNA into normal 142. Answer (1) plant cells eventually forming a tumor. Hint : An expensive technique for treatment of 151. Answer (3) genetic disease. Hint : Fluorescent tag used in staining nucleic acid. Sol. : Gene therapy is an expensive technique that Sol. : Ethidium bromide is also called bromoethane. uses genes to treat or prevent disease. In the future, Aniline blue used as a biological dye to stain this technique may allow doctors to treat a disorder glycogen and cell organelles that appear yellow by inserting a gene into a patient’s cell instead of green under violet light. Bromophenol blue is a using drugs or surgery. tracking dye. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
13/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-A)_(Hints & Solutions)
152. Answer (4) Sol. : pBR322 is a plasmid with 4361 base pairs. It Hint : ELISA is protein based technique. has unique restriction sites for more than forty restriction enzymes. It is the most widely used vector Sol. : PCR is a powerful technique used to identify in genetic engineering. YAC has maximum carrying many genetic disorders. ELISA can detect proteins capacity among given vectors. like antigens or antibodies. 161. Answer (1) 153. Answer (2) Hint : Monocot crop with yellow core. Hint : PCR is replication on a grander scale. Sol. : Biofortification increases the nutritional value Sol. : A single PCR involves three temperature in crops. Golden rice is genetically modified in order dependent steps : Denaturation, Annealing and to produce enhanced amount of beta carotene, Primer extension (polymerisation). Taq polymerase which is not normally produced in rice. Beta cannot work on RNA samples. carotene is converted into vitamin A when 154. Answer (3) metabolized by the human body. Hint : LacZ undergoes insertional inactivation 162. Answer (1) Sol. : Blue colonies represent non-recombinants. Hint : Identify covalent bonds. R All transformants have intact Amp gene. Sol. : Insulin is a relatively small protein, 155. Answer (4) comprising two polypeptides, one of 21 amino acids Hint : Agitation is needed to mix nutrients and keep (the A chain) and the other 30 amino acids (the B fermentation homogenous. chain) that are linked together by disulphide bonds/bridges. Sol. : A popular bioreactor for continuous fermentation is the sparged tank bioreactor through 163. Answer (4) which sterile bubbles are sparged. Hint : Choose a primate. 156. Answer (2) Sol. : Polly and Molly, two ewes, were the first Hint : Agarose gel is commonly used for this mammals to have been successfully cloned from an technique. adult somatic cell and to be transgenic at the same time. Sol. : The use of agarose gel electrophoresis revolutionized the separation of DNA fragments. 164. Answer (4) The phosphate backbone of the DNA (and RNA) Hint : Mineral usage from soil is efficient in case of molecule is negatively charged, therefore when transgenic plants placed in an electric field, DNA fragments will Sol. : Transgenic plants prevent early exhaustion of migrate to the positively charged anode based on fertility of soil. size. 165. Answer (2) 157. Answer (3) Hint : This enzyme assembles nucleotides. Hint : Select an anticoagulant. Sol. : At high temperatures, Taq polymerase and Sol. : Synthetic hirudin gene is introduced into Pfu are used as they link nucleotides to a DNA Brassica napus. The resulting transgenic plant primer, thereby replicating the DNA template. yielded seeds in which hirudin accumulates. The Thermostable enzymes do not break down at high hirudin is purified and used as medicine. temperatures, necessary for copying DNA using a 158. Answer (2) PCR. Hint : cry-IIAb controls Helicoverpa armigera. 166. Answer (2) Sol. : cry-IIAb and cry-IAc are genes for controlling Hint : It is often labelled with a radioactive moiety. bollworm whereas cryIAb controls corn borer. Gene Sol. : A probe is a fragment of DNA or RNA of for synthesis of -carotene has been taken from variable length used to detect the presence of plant daffodil. nucleotide sequences that are complementary to 159. Answer (1) the sequence in the probe. Somatic hybridization involves fusion of plant cells of different varieties. Hint : Enzymes which act at palindromic sites. 167. Answer (3) Sol. : Restriction endonucleases are called n molecular scissors as they cut the DNA strands at Hint : 2 where ‘n’ is number of cycles. particular locations known as restriction sites. Sol. : PCR is a common and indispensable 160. Answer (2) technique used in medical laboratory research for variety of applications including biomedical research Hint : It was developed by Boliver and Rodriguez. and criminal forensics 230 = 1 billion. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
14/16 Test-4 (Code-A)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
168. Answer (2) Sol. : Roundup is trade name for herbicide Hint : The DNA fragments separate or resolve glyphosate. This herbicide blocks synthesis of according to their size. aromatic amino acid phenylalanine, tryptophan and tyrosine. Sol. : The separated DNA can be visualised only after staining the DNA with a compound known as 175. Answer (1) ethidium bromide followed by exposure to UV Hint : Gene substraction. radiation Sol. : Many proteins such as human insulin, 169. Answer (2) human growth hormone and a wide range of Hint : Agrobacterium is responsible for pharmaceuticals are mass produced from opportunistic infections in plants. genetically engineered bacteria and fungi. Sol. : Agrobacterium tumefaciens has been 176. Answer (3) termed as “nature’s genetic engineer”. Hint : In Flavr Savr reduced production Agrobacterium causes tumors (crown gall disease) polygalacturonase is seen. and usually infects plants through an open wound. Sol. : Flavr Savr tomatoes are the genetically 170. Answer (4) modified tomatoes. They have longer and more Hint : Each restriction enzyme recognizes a flavourful shelf life than the normal tomatoes due to specific nucleotide sequence in DNA. the presence of gene that reduces the production of Sol. : Restriction enzymes serve as chemical polygalacturonase (cell wall degrading enzyme knives to cut genes into defined fragments. responsible for fruit ripening). 171. Answer (4) 177. Answer (4) Hint : This bacteria is found in our large intestine Hint : This committee follows a case by case as symbiont. system of approvals. Sol. : Human insulin gene is spliced into a plasmid. Sol. : Genetic Engineering Appraisal Committee E. coli bacteria is then “infected” with that plasmid. (GEAC) approves or denies genetically engineered The bacteria take up the plasmid and incorporate organisms/cells from labs, hospitals etc. into the new gene and now a new strain of insulin environment. producing E. coli bacteria can be cultured in bulk to 178. Answer (4) create insulin inexpensively. Hint : It is a nucleic acid based technique. 172. Answer (3) Sol. : PCR is used for amplification of DNA. Hint : Identify a cash crop 179. Answer (4) Sol. : First genetically modified crop, an antibiotic Hint : First step of PCR renders a double stranded resistant tobacco plant was produced in 1982. Bt template DNA into two single strands. cotton produces an insecticide to combat bollworm. Sol. : The three stages of PCR are denaturation, 173. Answer (1) annealing, and primer extension. The denaturation Hint : It makes use of enzyme reverse occurs when the DNA is heated at 94°C to make it transcriptase. single stranded. Annealing occurs when the Sol. : Retrovirus is commonly used to transfer a complimentary strands are bonded. DNA fragment in human lymphocytes as they have 180. Answer (3) a very high division potential. So after modification Hint : Protein present in milk. i.e., after inactivation of the oncogenic genes of that virus it would become a vector which can carry our Sol. : 1-antitrypsin was produced by first transgenic desired gene and replicate it with itself. sheep named ‘Tracy’. Streptokinase is a clot buster 174. Answer (3) and hirudin is anticoagulant obtained from Hint : Aromatic amino acid. transgenic plant Brassica napa.
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15/16 Test-4 (Code-B)_(Answers) All India Aakash Test Series for NEET-2020
All India Aakash Test Series for NEET - 2020
TEST - 4 (Code-B)
Test Date : 08/12/2019
ANSWERS
1 (2) 37 (4) 73 (1) 109 (4) 145 (4) 2 (1) 38 (2) 74 (4) 110 (2) 146 (4) 3 (2) 39 (1) 75 (4) 111 (3) 147 (2) 4 (2) 40 (2) 76 (3) 112 (4) 148 (2) 5 (3) 41 (3) 77 (2) 113 (3) 149 (3) 6 (1) 42 (1) 78 (4) 114 (1) 150 (2) 7 (3) 43 (4) 79 (2) 115 (3) 151 (2) 8 (1) 44 (3) 80 (2) 116 (4) 152 (4) 9 (1) 45 (2) 81 (2) 117 (2) 153 (4) 10 (3) 46 (1) 82 (3) 118 (3) 154 (1) 11 (1) 47 (3) 83 (4) 119 (1) 155 (1) 12 (1) 48 (3) 84 (1) 120 (3) 156 (2) 13 (3) 49 (4) 85 (4) 121 (1) 157 (1) 14 (4) 50 (1) 86 (4) 122 (4) 158 (2) 15 (4) 51 (2) 87 (4) 123 (2) 159 (3) 16 (3) 52 (1) 88 (4) 124 (2) 160 (2) 17 (4) 53 (3) 89 (2) 125 (4) 161 (4) 18 (4) 54 (1) 90 (4) 126 (3) 162 (3) 19 (3) 55 (2) 91 (3) 127 (3) 163 (2) 20 (2) 56 (2) 92 (4) 128 (4) 164 (4) 21 (1) 57 (2) 93 (2) 129 (2) 165 (3) 22 (3) 58 (3) 94 (3) 130 (2) 166 (3) 23 (2) 59 (2) 95 (2) 131 (3) 167 (3) 24 (1) 60 (1) 96 (4) 132 (4) 168 (2) 25 (3) 61 (4) 97 (2) 133 (1) 169 (1) 26 (2) 62 (1) 98 (3) 134 (2) 170 (2) 27 (3) 63 (3) 99 (3) 135 (3) 171 (4) 28 (3) 64 (2) 100 (1) 136 (3) 172 (3) 29 (4) 65 (3) 101 (2) 137 (4) 173 (1) 30 (1) 66 (3) 102 (3) 138 (4) 174 (1) 31 (3) 67 (3) 103 (4) 139 (4) 175 (3) 32 (1) 68 (2) 104 (1) 140 (3) 176 (4) 33 (2) 69 (3) 105 (2) 141 (1) 177 (1) 34 (3) 70 (1) 106 (4) 142 (3) 178 (1) 35 (1) 71 (3) 107 (3) 143 (1) 179 (4) 36 (3) 72 (4) 108 (2) 144 (3) 180 (3)
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1/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
HINTS & SOLUTIONS [PHYSICS] 1. Answer (2) Sol. : If P is at low potential and Q at high potential, Hint and Sol. : Base in transistor is lightly doped and then no diode will conduct, so thin. RPQ = 4 2. Answer (1) Hint : During decay mass number decrease by 4 and no change in mass number during decay. Sol. : 4 × n = 32 n = 8 and 6 3. Answer (2) Hint and Sol. : 7. Answer (3) Hint and Sol. : In common emitter amplifier input and output voltage are in opposite phase. V A out ABY Vin
0 0 1 Vout = 0.04 × 100 = 4 V 1 0 0 3 V(4 V)sin t 0 1 0 2 1 1 0 8. Answer (1) Hint and Sol. : It is a NOR gate Potential drop in D = 0.7 V 4. Answer (2) 2 Hint : Zener diode will conduct when potential difference across zener is more than break down voltage.
Sol. :
0.7 Current in 3.5 k 0.2 mA Potential drop across dropping resistance = 20 V 3.5 103 20 9. Answer (1) Current in dropping resistance i 40 mA 500 Hint and Sol. : Energy released per fission = 200 MeV 10 Current in 1 k, i 10 mA = 3.2 × 10–11 J 1 1000 Total energy produced per day Current in zener diode = (40 – 10) mA = 100 × 106 × 86400 = 30 mA = 8.64 × 1012 J 5. Answer (3) Number of fission per day = n Hint and Sol. : Diode is in forward bias, hence Efficiency of reactor = 80% (3 1) I 20 mA 80 12 100 n × 3.2 × 10–11 × 8.64 10 100 6. Answer (1) 8.64 1012 Hint : Current will flow in junction diode when it is n 3.375 1023 forward biased. 3.2 0.8 1011
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2/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
235 3.375 1023 A B Y Mass of uranium 23 6.023 10 0 0 1 = 132 g (app.) 1 0 1 10. Answer (3) 0 1 1 Hint : The rate of disintegration of x1 is more than x2. 1 1 0 Sol. : N N e10 t The given truth table is for NAND gate. x1 0 15. Answer (4) N N et x2 0 Hint and Sol. : In forward biases P-type is at high 10 t potential and n-type at low potential so diode in Nx e 1 option (4) is forward biased. N et x2 16. Answer (3)
1 9 t Hint and Sol. : In reverse bias the barrier potential e (V0 + V ) becomes large. Therefore, the diffusion e3 r current is usually negligible for reverse bias. 1 1 17. Answer (4) 3 9t e e Hint and Sol. : Extrinsic semiconductors are also e9t = e3 electrically neutral because they contain equal number of acceptors and donors. 9t = 3 18. Answer (4) 1 t Hint and Sol. : A zener diode is highly doped and 3 used in reverse biased. 11. Answer (1) 19. Answer (3) Hint and Sol. : Hint and Sol. : As doping concentration increased Truth table of NOR gate. width of depletion layer decreases. 20. Answer (2) Hint and Sol. : Concentration of holes is greater than number of free electrons, so it is a P-type ABYY semiconductor. 0 0 0 1 21. Answer (1) 1 0 1 0 Hint : Mean life = 1.44 T1/2 0 1 1 0 50 N Sol. : Initial value 50% NN 0 1 1 1 0 0100 0 2
12. Answer (1) 3.125 N0 Remaining value 3.125% NN0 0 Hint : When amplifiers are connected in series 100 32 n then resultant voltage gain A = A1 × A2. 1 NN 0 Sol. : Net voltage gain A = 20 × 20 = 400 2 n 13. Answer (3) NN 1 0 0 R 32 2 2 Hint : Power gain P 2 L R 4 n in 1 1 2 2000 2 2 Sol. : P (5) 5000 10 40 Half life of element 10 s 14. Answer (4) 4 Hint and Sol. : Truth table of given circuit Mean life = 10 × 1.44 = 14.4 s
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3/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
22. Answer (3) M Am d P Hint and Sol. : As the mass of radioactive sample 4 V R3 is increased, then number of nuclei will also 3 increase, so activity will increase. Decay constant is 1 the property of element, so it remains same. 3 RRA 0 23. Answer (2) 3AmP Hint : Energy will be released in nuclear reaction, d 3 when energy of product nuclei is greater than the 4RA0 energy of reactant nuclei d A° Sol. : Energy of product nuclei = 4c 29. Answer (4) Hint and Sol. : Wavelength of first line of Balmer Energy of reactant nuclei = (a + 3b) series. Energy released = 4c – (a + 3b) 1 1 1 = 4c – a – 3b R 22 3 2 24. Answer (1) B 1 1 5R Hint : In this process momentum remains constant. R 4 9 36 Sol. : According to law of conservation of Wavelength of second line of lyman series. momentum 1 1 1 8R 0 m v m v R 1 1 2 2 1 9 9 0 = m v – m (27v) L 1 2 32 B m1 27 L 5 m2 1 30. Answer (1) 4 Z R3 v 1 27 Hint : Speed of electron in any orbit n 3 n 4 3 1 n2 R2 Radius of Bohr orbit r 3 n Z R : R = 3 : 1 1 2 Sol. : vn = rnn 25. Answer (3) 1 n 1 v r Hint and Sol. : 1 atomic mass unit [mass of n n 12 1 12 n one 6C carbon atom]. 2 vn n 26. Answer (2) Hint and Sol. : Nuclear forces between two 31. Answer (3) nucleons having like spin is different than those Hint : The radius of Bohr orbit of hydrogen like having unlike spin, so nuclear forces are spin n2 dependent. element is rn 0.529 Å Z 27. Answer (3) Hint and Sol. : Sol. : Radius of first orbit of hydrogen r1 = 0.529 Å Radius of second orbit of helium ion 0.529 4 r Å 2 2 = 1.058 Å = 10.58 × 10–11 m
-particle of all the energies from 0 to a certain 32. Answer (1) maximum value emitted from same element. So Hint and Sol. : Intensity of x-rays depends on spectrum is continuous spectrum. number of photons, which depends on number of 28. Answer (3) electrons striking at target. The number of electrons Hint and Sol. : Average mass density can be increased by increasing current in filament.
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4/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
33. Answer (2) 37. Answer (4) Hint and Sol. : Absorption of energy is possible only Hint and Sol. : One of the electrons enters in from ground state n = 1. So in absorption spectrum magnetic field, so there is no change in magnitude of possible spectral lines are 3. linear momentum. Hence 1 remains same. While 34. Answer (3) second electron enters in electric field, and it will accelerate, so its magnitude of momentum may Hint : Total energy of electron in any orbit is half of increase, decrease or at some instant may be equal potential energy. to the first electron. Hence 1 may be greater than 1 Ze2 Sol. : Total energy of electron E equal or less than 2. Tot 4 2r 0 n 38. Answer (2) 1 Ze2 Hint and Sol. : Stopping potential is greater for b Potential energy of electron EPot than a it means > . Saturation photo current is 40 rn b a same for a and b it means I = I E : E = 2 : 1 a b Pot Tot 39. Answer (1) 35. Answer (1) Hint and Sol. : Point source is placed at focus of Hint : Einstein’s equation of photoelectric effect. convex lens, so after refraction light rays become hc parallel. Hence on changing the distance, there is Sol. : eV0 w no change in number of photons striking on photocell. So saturated current and cut-off potential hc remains same. Case - I : 3eV w ...(i) 0 40 Answer (2) Hint : Kinetic energy of charged particle = qV hc Case - II : eV0 w ...(ii) h h 2 Sol. : de-Broglie wavelength p Multiply equation (ii) with 3 and subtract equation (i) 2 mK hc hc 2 h 2w 0 2 w For deuteron (H)1 D 2 2 2qV (2 m)
hc hc 4 h 2 For -particle (2 He ) 0 2 2(2q ) V (4 m) = 4 2 0 D 36. Answer (3) 1 Hint : In electric fields particle will accelerate so its 41. Answer (3)
momentum will change. 1 2 Hint : h mv Sol. : Electric force on charge F qEi 2 Sol. : qE Acceleration of charge a i 1 2 m Case - I : h mv ...(i) 2 1 Velocity along x-axis vx (as a function of time) 1 2 qE Case - II : 4h mv2 ...(ii) t 2 m Divide (i) by (ii) h h 2 h mv1 2 2 2 3mv0 ()()mv qEt 2 0 4h mv2 2 9m2v 2 = m2v 2 + q2E2t2 2 2 0 0 4mv1 8 mv 2 2 8m2v 2 = q2E2t2 0 2 2 6 v24 v 1 2 2mv m t 0 qE v2 2 v 1
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5/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
42. Answer (1) = 11.1 eV Hint : Maximum kinetic energy of photo electron 12400 = eVC Wavelength of photons = Å 11.1 Sol. : Work function of surface = h0 1117 Å 6.6 1034 5 10 14 1.6 1019 Wavelength 1117 Å lies in ultraviolet region. = 2.06 eV 44. Answer (3) Wavelength of incident radiation = 4000 Å E Hint : Momentum of photon p 12400 c Energy of incident radiation = = 3.1eV 4000 Sol. : Energy of photon = 3 MeV
–13 Energy of photon = + eVc = 3 × 1.6 × 10 joule
3.1 = 2.06 + eVc E 3 1.6 1013 p 8 eVc = 1.04 eV c 3 10 Vc = 1.0 V p = 1.6 × 10–21 kg m/s 43. Answer (4) 45. Answer (2) Hint : Energy of photon = 0 + eV0 Hint and Sol. : Light of all wavelengths in vacuum Sol. : Work function of surface = 5.1 eV travel with same speed, so Energy of incident photons = (5.1 + 6) eV c °
[CHEMISTRY] 46. Answer (1) 50. Answer (1) Hint : Partial reduction take place Hint : DNA contains four bases : A, G, C, T Sol. : DNA does not contain uracil (U) Sol. : 51. Answer (2) Hint : Given carbohydrate is sucrose Sol. : Sucrose consists of -D-glucose and -D- 47. Answer (3) fructose 52. Answer (1) Hint : C2H4O is an aldehyde. Hint : Sol. :
Sol. : Formaldehyde gives positive Tollens’ test.
53. Answer (3) 48. Answer (3) Hint : This is an example of Iodoform test. Hint : Low density polythene is used in the insulation of electricity carrying wires. Sol. : 49. Answer (4) Hint : Ester is reduced into aldehyde by using DIBAL – H (i) DIBAL H in toluene CH (CH ) COOC H CH (CH ) CHO 3 2 9 2 5 3 2 9 (ii) H3 O
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6/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
54. Answer (1) Sol. : Hint : Nitrobenzene gives different products in alkaline medium under different conditions.
60. Answer (1) Sol. : Hint : Lone pairs of N2 and N3 are involve in resonance with keto group. 55. Answer (2) Hint : During cannizzaro reaction, disproportionation of aldehydes takes place with conc. NaOH. Sol. : Sol. : Aldehydes which do not have an -hydrogen atom, undergo oxidation and reduction (disproportionation) reaction on heating with concentrated NaOH or KOH. 61. Answer (4) For example : Formaldehyde, benzaldehyde. Hint : Carboxylic acids are generally stronger acid 56. Answer (2) than alcohols and phenols. Hint : Et—Br undergoes S 2 reaction in Gabriel N Sol. : phthalimide synthesis of 1° amines.
Sol. :
62. Answer (1) Hint : Cyanide group (CN) is reduced into – CH2NH2
Sol. :
57. Answer (2) 63. Answer (3) Hint : B·P· of carboxylic acid is more than that of aldehydes with comparable molecular mass. Hint : Acetanilide is Sol. : Formic acid exists as dimer in the vapour phase. Benzoic acid is nearly insoluble in cold water due to larger size of its hydrophobic ring. Acetic acid is miscible in water. Sol. : 58. Answer (3) Hint : Cleavage of > C = C < take palce Sol. :
59. Answer (2) Hint : Nitrile on complete hydrolysis, gives carboxylic acids. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
7/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
64. Answer (2) Sol. : O CH3 COOH NH 3 CH 3 COO NH 4 HO2 Hint : Acrolein is H — C— CH CH 2 O Sol. : CH3 — C— NH 2 69. Answer (3) Hint : Albumin is a globular protein. Sol. : Globular proteins are usually soluble in water. 70. Answer (1)
Hint : Essential amino acids cannot be synthesised 65. Answer (3) in the body. Hint : Sol. : Essential amino acids : Histidine 71. Answer (3) Hinsberg’s reagent is Hint :
reacts with Br2 water, NH2OH, HCN Sol. : Sol. : reacts with acetic anhydride 2°-amine CH3NHCH3 reacts with Hinsberg’s reagent (or, benzenesulphonyl chloride). 72. Answer (4) 66. Answer (3) Hint : An elastomer involves weakest van der Waals Hint : Lower aliphatic amines are more soluble in interactions. water than higher aliphatic amines. Sol. : Buna–N is an elastomer Sol. : Solubility of amines in water decreases with increase in molar mass of amines due to increase 73. Answer (1) in size of the hydrophobic alkyl part. Hint : Tranquilizers relieve or reduce the stress and 67. Answer (3) anxiety. Hint : Benzene diazonium chloride reacts with Sol. : Tranquilizers : Equanil, Phenelzine phenol and aniline in basic and acidic medium 74. Answer (4) respectively. Hint : PHBV and Nylon-2-Nylon 6 are biodegradable Sol. : polymer. 75. Answer (4) Hint : D-ribose is in furanose form Sol. :
68. Answer (2) Hint : 76. Answer (3) O Hint : In maltose, C-1 of one -D-Glucopyranose is linked to C-4 of another -D-Glucopyranose Acetamide is CH — C— NH 3 2 molecule by glycosidic linkage.
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8/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
82. Answer (3) Hint : Compounds in which carbonyl group is least hindered are found to be most reactive towards Sol. : nucleophilic addition reaction. Sol. : Carbonyl group in formaldehyde is least hindered. 77. Answer (2) 83. Answer (4) Hint : Hint : Polypropene is used in the manufacture of ropes. Benzenamine is Sol. : Polystyrene is used as insulator. Urea-formaldehyde resin is used for making Sol. : Order of basic character : unbreakable cups and laminated sheets. Bakelite (Polymer of phenol and formaldehyde) is used for making electrical switches)
78. Answer (4) 84. Answer (1) Hint : Xerophthalmia is the hardening of cornea of Hint : Homopolymers consist of only one type of eye. monomeric species Sol. : This happens due to the deficiency of Sol. : vitamin A. Polymer Monomer 79. Answer (2) PVC Vinyl chloride Hint : Teflon Tetrafluoroethene Artificial sweetener Sweetness value in Neoprene 2-chloro-1,3-butadiene Comparison to cane sugar 85. Answer (4) Aspartame 100 Hint : Cinnamaldehyde is an , unsaturated Saccharin 550 aromatic aldehyde. Sucralose 600
Alitame 2000 80. Answer (2) 86. Answer (4) Hint : PCC is a mild oxidising agent. Hint : Carboxylic acid is a stronger acid than Sol. : carbonic acid.
CH CH CH CH OHPCC CH CH CH CHO 3 2 2 2 3 2 2 Sol. : Butanal 81. Answer (2)
Hint : CrO2Cl2 can be used to oxidise toluene to benzaldehyde. Sol. :
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9/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
87. Answer (4)
Hint : Sol. :
88. Answer (4) Hint : Nylon 6 is a polyamide Sol. :
90. Answer (4)
Hint : N-Ethylbenzamide is 89. Answer (2) Sol. : Hint :
[BIOLOGY] 91. Answer (3) 96. Answer (4) Hint : All the buses of Delhi were shifted to CNG by Sol. : Painful skeletal deformities or itai-itai is due year 2002 by the government. to cadmium toxicity. Sol. : CNG burns more efficiently than petrol and 97. Answer (2) diesel. It cannot be adulterated like petrol and Hint : Polyblend mixed with bitumen is used to lay diesel. roads. 92. Answer (4) Sol. : Polyblend is a fine powder of modified Hint : Water hyacinth (Eichhornia crassipes) is recycled plastic developed by Ahmed Khan. called terror of Bengal. 98. Answer (3) Sol. : Water hyacinth is an invasive problematic Hint : Ozone depletion can cause UV radiation aquatic weed of eutrophic lakes. mediated damages to humans. 93. Answer (2) Sol. : If ozone depletion occurs, UV radiation Sol. : Ramesh Chandra Dagar is related to organic specially UV-B can cause DNA damage, mutations, farming in Haryana, India. skin cancer, ageing of skin, damage to cornea and snow blindness. 94. Answer (3) CO fertilisation effect and cooling of troposphere Hint : Jhum cultivation is slash and burnt 2 are associated with greenhouse effect. agricultural practice used in north-eastern states of India. 99. Answer (3) Sol. : Jhum cultivation leads to deforestation while Hint : Global warming leads to melting of polar ice Van Mahotsava, Chipko movement and Joint forest caps. management are associated with maintenance and Sol. : Global warming causes melting of polar ice conservation of forests. caps and rise in sea level. 95. Answer (2) 100. Answer (1) Hint : This area is at the south pole of earth. Hint : Ecosanitation uses dry composting toilets to Sol. : Every year between late August and early recycle human excreta into natural fertilizers. October ozone hole is observed over the Antarctic Sol. : EcoSan toilets are hygienic, cost-effective region. and efficient solution of human waste disposal. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
10/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
101. Answer (2) Sol. : According to Rivet popper hypothesis, loss Sol. : High concentration of DDT causes thinning of key species is major threat to ecosystem safety of egg shells and their premature breaking by because key species drive major ecosystem disturbing calcium metabolism. functions. 102. Answer (3) 111. Answer (3) Hint : Biochemical oxygen demand (BOD) is a Hint : Direct economic benefits derived from nature measure of oxygen required by aerobic are called narrowly utilitarian benefits. decomposers for degradation of organic waste Sol. : Pollination, oxygen and aesthetic pleasure material in water. are broadly utilitarian benefits of ecosystem. Rest Sol. : Increase in amount of biodegradable organic are narrow utilitarian benefits. wastes in water increases BOD and leads to low 112. Answer (4) amount of dissolve oxygen. Hint : in-situ conservation strategies are also 103. Answer (4) called on-site conservation strategies. Sol. : In Bhopal gas tragedy, the poisonous gas Sol. : Hot-spots, national parks, sacred lakes and Methyl isocynate (MIC) was leaked. biosphere reserves are in-situ conservation 104. Answer (1) strategies. Hint : In the 3rd session of conference of parties a 113. Answer (3) protocol was proposed for countries to take Hint : Species with small population are more appropriate measure to reduce overall levels of susceptible to extinction. greenhouse gas emission. Sol. : Large body size, low reproductive rate, high Sol. : 3rd session of conference of parties (COP) trophic level in food chain, fixed habitat and was held in Kyoto, Japan was an important initiative migratory route are some characteristics of those to take measures towards global climate change. species which are highly susceptible to extinction. 105. Answer (2) 114. Answer (1) Hint : High sulphur content in petrol or diesel Sol. : Cichlid fishes of Lake Victoria of East Africa increases SO2 pollution. are the native species of that area. Sol. : One of the important measures taken by the 115. Answer (3) government to reduce air pollution is, use of low- Sol. : Some examples of most recent extinctions sulphur petrol or diesel. are 106. Answer (4) Dodo – Mauritius Sol. : Ozone (O3) is a secondary air pollutant. Quagga – Africa 107. Answer (3) Thylacine – Australia Hint : Trees such as Neem and Ashoka are Steller’s sea cow – Russia planted under green muffler scheme to reduce noise 116. Answer (4) pollution. Hint. : Biodiversity is important for ecosystem Sol. : stability, productivity, resistance etc. Removal of particulate matter – Electrostatic Sol. : Communities with more biodiversity are precipitator. more stable and more resistant to natural disturbances, man-made disturbances and invasion Controls SO2 pollution – Scrubber by alien species. Rich biodiversity decreases year- Hospital waste disposal – Incinerators to-year variations in productivity of an ecosystem. 108. Answer (2) 117. Answer (2) Sol. : Snow leopards are protected in Hint : Among the invertebrates, insects are the Khangchendzonga National park of Gangtok, most species rich. Sikkim. Sol. : In the given pie chart 109. Answer (4) Sol. : Khasi and Jaintia hills are situated in A – Insects Meghalaya. B – Molluscs 110. Answer (2) C – Crustaceans Hint : Rivet popper hypothesis was given by Paul 118. Answer (3) Ehrlich which explains relation between biodiversity Sol. : Species area relationship of biodiversity was and ecosystem health. given by Alexander von Humboldt. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
11/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
119. Answer (1) 127. Answer (3) Hint : India is on 8th rank among 12 megadiversity Sol. : For tree ecosystem, pyramid of number countries. could be inverted or spindle shaped. Sol. : India has only 2.4% of world’s land area but 128. Answer (4) it possesses 8.1% species diversity of the world. Sol. : During succession, total biomass of the 120. Answer (3) ecosystem increases. Sol. : Humus is dark coloured, amorphous, more 129. Answer (2) or less decomposed organic matter. It is slightly Sol. : Ecological pyramids accommodate a simple acidic and resistant to microbial action. food chain not a food web. Saprophytes, 121. Answer (1) decomposers and microbes are not given any place Hint : Phosphorus cycle is a sedimentary cycle. in ecological pyramid. Sol. : There is no respiratory release of 130. Answer (2) phosphorus into atmosphere by living organisms. Hint : Plants capture approximately 1-5% of 122. Answer (4) incident solar radiation for photosynthesis. Sol. : Reservoir pool of a gaseous cycle is Sol. : Plants capture 2-10% of PAR for atmosphere or hydrosphere. Lithosphere or earth’s synthesising their food. crust is the reservoir pool for sedimentary cycle. 131. Answer (3) 123. Answer (2) Hint : In a food chain, transfer of energy at different Hint : Part of water soluble substances present in trophic levels occur according to “10% law of energy fragmented and decomposing detritus go down in transfer”. soil horizon by percolating water is called leaching. Sol. : If NPP is 2000 J then fixed energy in Sol. : During decomposition, fragmentation of herbivores (primary consumer) is 200 J, secondary detritus involves activity of detrivores while consumers 20 J, tertiary consumers 2 J. humification and mineralisation involve activity of saprophytic fungi and bacteria. Leaching process 132. Answer (4) does not directly involve activity of living organisms. Sol. : Detritus food chain begins with detritus or 124. Answer (2) dead organic matter. Hint : In hydrarch succession, the successional 133. Answer (1) series progress from hydric to mesic conditions. Hint : Stratification is vertical distribution of Sol. : Transitional communities in hydrarch different species occupying different levels. succession are – Sol. : In a forest, vertical subdivision or strata are Submerged plant stage Submerged free-floating a. Trees – Top layer plant stage Reed-swamp stage Marsh- b. Shrubs – Second layer meadow stage Scrub stage. c. Grasses and herbs – Bottom layer 125. Answer (4) 134. Answer (2) Hint : In secondary succession, pioneer Hint : Decomposition process is slower when community establishes with comparatively more detritus contains complex and water-insoluble ease. compounds. Sol. : Secondary succession starts in areas that Sol. : Decomposition of detritus containing lignin, somehow lost all the living organisms that existed chitin and cellulose is slower. Process of there. It has some soil or sediment existing at the decomposition requires aeration, activity of soil site of succession. Here climax is also reached more microbes, warm and moist soil. quickly. 126. Answer (3) 135. Answer (3) Hint : Anthropogenic ecosystems are created and Hint : Net primary productivity is the rate of organic maintained by humans. matter build up or stored by producers in excess of respiratory utilization. Sol. : Characteristics of anthropogenic ecosystem Sol. : Net primary productivity (NPP) is the a. Low species diversity. available biomass for the consumption of b. High productivity. heterotrophs i.e. herbivores and decomposers. It c. Presence of simple food chain. depends upon various environmental factors. NPP d. Absence of self regulatory mechanisms. of terrestrial ecosystems is generally higher than e. Little cycling of nutrients. ocean. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
12/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
136. Answer (3) Sol. : Retrovirus is commonly used to transfer a Hint : Protein present in milk. DNA fragment in human lymphocytes as they have a very high division potential. So after modification Sol. : 1-antitrypsin was produced by first transgenic i.e., after inactivation of the oncogenic genes of that sheep named ‘Tracy’. Streptokinase is a clot buster virus it would become a vector which can carry our and hirudin is anticoagulant obtained from desired gene and replicate it with itself. transgenic plant Brassica napa. 144. Answer (3) 137. Answer (4) Hint : Identify a cash crop Sol. : First genetically modified crop, an antibiotic Hint : First step of PCR renders a double stranded resistant tobacco plant was produced in 1982. Bt template DNA into two single strands. cotton produces an insecticide to combat bollworm. Sol. : The three stages of PCR are denaturation, 145. Answer (4) annealing, and primer extension. The denaturation occurs when the DNA is heated at 94°C to make it Hint : This bacteria is found in our large intestine single stranded. Annealing occurs when the as symbiont. complimentary strands are bonded. Sol. : Human insulin gene is spliced into a plasmid. E. coli bacteria is then “infected” with that plasmid. 138. Answer (4) The bacteria take up the plasmid and incorporate Hint : It is a nucleic acid based technique. the new gene and now a new strain of insulin Sol. : PCR is used for amplification of DNA. producing E. coli bacteria can be cultured in bulk to create insulin inexpensively. 139. Answer (4) 146. Answer (4) Hint : This committee follows a case by case Hint : Each restriction enzyme recognizes a system of approvals. specific nucleotide sequence in DNA. Sol. : Genetic Engineering Appraisal Committee Sol. : Restriction enzymes serve as chemical (GEAC) approves or denies genetically engineered knives to cut genes into defined fragments. organisms/cells from labs, hospitals etc. into 147. Answer (2) environment. Hint : Agrobacterium is responsible for 140. Answer (3) opportunistic infections in plants. Hint : In Flavr Savr reduced production Sol. : Agrobacterium tumefaciens has been polygalacturonase is seen. termed as “nature’s genetic engineer”. Sol. : Flavr Savr tomatoes are the genetically Agrobacterium causes tumors (crown gall disease) modified tomatoes. They have longer and more and usually infects plants through an open wound. flavourful shelf life than the normal tomatoes due to 148. Answer (2) the presence of gene that reduces the production of Hint : The DNA fragments separate or resolve polygalacturonase (cell wall degrading enzyme according to their size. responsible for fruit ripening). Sol. : The separated DNA can be visualised only 141. Answer (1) after staining the DNA with a compound known as Hint : Gene substraction. ethidium bromide followed by exposure to UV radiation Sol. : Many proteins such as human insulin, human growth hormone and a wide range of 149. Answer (3) pharmaceuticals are mass produced from Hint : 2n where ‘n’ is number of cycles. genetically engineered bacteria and fungi. Sol. : PCR is a common and indispensable 142. Answer (3) technique used in medical laboratory research for variety of applications including biomedical research Hint : Aromatic amino acid. and criminal forensics 230 = 1 billion. Sol. : Roundup is trade name for herbicide 150. Answer (2) glyphosate. This herbicide blocks synthesis of Hint : It is often labelled with a radioactive moiety. aromatic amino acid phenylalanine, tryptophan and tyrosine. Sol. : A probe is a fragment of DNA or RNA of variable length used to detect the presence of 143. Answer (1) nucleotide sequences that are complementary to Hint : It makes use of enzyme reverse the sequence in the probe. Somatic hybridization transcriptase. involves fusion of plant cells of different varieties. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
13/16 All India Aakash Test Series for NEET-2020 Test-4 (Code-B)_(Hints & Solutions)
151. Answer (2) 159. Answer (3) Hint : This enzyme assembles nucleotides. Hint : Select an anticoagulant. Sol. : At high temperatures, Taq polymerase and Sol. : Synthetic hirudin gene is introduced into Pfu are used as they link nucleotides to a DNA Brassica napus. The resulting transgenic plant primer, thereby replicating the DNA template. yielded seeds in which hirudin accumulates. The Thermostable enzymes do not break down at high hirudin is purified and used as medicine. temperatures, necessary for copying DNA using a PCR. 160. Answer (2) 152. Answer (4) Hint : Agarose gel is commonly used for this technique. Hint : Mineral usage from soil is efficient in case of transgenic plants Sol. : The use of agarose gel electrophoresis Sol. : Transgenic plants prevent early exhaustion of revolutionized the separation of DNA fragments. fertility of soil. The phosphate backbone of the DNA (and RNA) molecule is negatively charged, therefore when 153. Answer (4) placed in an electric field, DNA fragments will Hint : Choose a primate. migrate to the positively charged anode based on Sol. : Polly and Molly, two ewes, were the first size. mammals to have been successfully cloned from an 161. Answer (4) adult somatic cell and to be transgenic at the same time. Hint : Agitation is needed to mix nutrients and keep fermentation homogenous. 154. Answer (1) Sol. : A popular bioreactor for continuous Hint : Identify covalent bonds. fermentation is the sparged tank bioreactor through Sol. : Insulin is a relatively small protein, which sterile bubbles are sparged. comprising two polypeptides, one of 21 amino acids (the A chain) and the other 30 amino acids (the B 162. Answer (3) chain) that are linked together by disulphide Hint : LacZ undergoes insertional inactivation bonds/bridges. Sol. : Blue colonies represent non-recombinants. 155. Answer (1) All transformants have intact AmpR gene. Hint : Monocot crop with yellow core. 163. Answer (2) Sol. : Biofortification increases the nutritional value Hint : PCR is replication on a grander scale. in crops. Golden rice is genetically modified in order to produce enhanced amount of beta carotene, Sol. : A single PCR involves three temperature which is not normally produced in rice. Beta dependent steps : Denaturation, Annealing and carotene is converted into vitamin A when Primer extension (polymerisation). Taq polymerase metabolized by the human body. cannot work on RNA samples. 156. Answer (2) 164. Answer (4) Hint : It was developed by Boliver and Rodriguez. Hint : ELISA is protein based technique. Sol. : pBR322 is a plasmid with 4361 base pairs. It Sol. : PCR is a powerful technique used to identify has unique restriction sites for more than forty many genetic disorders. ELISA can detect proteins restriction enzymes. It is the most widely used vector like antigens or antibodies. in genetic engineering. YAC has maximum carrying 165. Answer (3) capacity among given vectors. 157. Answer (1) Hint : Fluorescent tag used in staining nucleic acid. Hint : Enzymes which act at palindromic sites. Sol. : Ethidium bromide is also called bromoethane. Aniline blue used as a biological dye to stain Sol. : Restriction endonucleases are called glycogen and cell organelles that appear yellow molecular scissors as they cut the DNA strands at green under violet light. Bromophenol blue is a particular locations known as restriction sites. tracking dye. 158. Answer (2) 166. Answer (3) Hint : cry-IIAb controls Helicoverpa armigera. Hint : Transformed cell may turn into a tumor. Sol. : cry-IIAb and cry-IAc are genes for controlling bollworm whereas cryIAb controls corn borer. Gene Sol. : Agrobacterium tumefaciens invades plants for synthesis of -carotene has been taken from at the site of wound and delivers T-DNA into normal plant daffodil. plant cells eventually forming a tumor. Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph.011-47623456
14/16 Test-4 (Code-B)_(Hints & Solutions) All India Aakash Test Series for NEET-2020
167. Answer (3) by inserting a gene into a patient’s cell instead of Hint : Organisms belonging to largest phylum. using drugs or surgery. Sol. : Baculoviruses are insect pathogenic viruses 175. Answer (3) that are used for insect control and as tools to Hint : They are called molecular glue. produce recombinant proteins. They are particularly Sol. : DNA ligases form phosphodiester bonds valuable where traditional chemical insecticides between adjacent nucleotides and covalently link have become ineffective. two individual fragments of double-stranded DNA by 168. Answer (2) utilising energy from dNTPs. Endonucleases are Hint : It is genetic material of Reoviruses restriction enzymes. DNA polymerase synthesizes a Sol. : In nature, RNA is used for the regulation of new strand of DNA complementary to an existing specific genes and is also applied as a defence DNA template in 5 to 3 direction. against pathogens. 176. Answer (4) 169. Answer (1) Hint : Breaking dsDNA into ssDNA is DNA Hint : Bacterial cells must be made ‘competent’ to denaturation. take up DNA. Sol. : The temperature of melting (Tm) or Sol. : Other methods for insertion of recombinant denaturation is defined as the temperature at which DNA into the host cell/organism include 50% of double stranded DNA is changed to a single- microinjection, biolistic etc. stranded DNA. The process of breaking the 170. Answer (2) hydrogen bonds between the nucleotide base pairs in double stranded DNA requires energy. Hint : Extraction of desired product utilizes downstream processing. 177. Answer (1) Sol. : Downstream processing is the name given to Hint : It is produced by Streptococcus. the stage after fermentation when the desired Sol. : Myocardial infarction can now be treated by product is recovered and purified. genetic engineering. Erythropoietin is synthesized 171. Answer (4) from J.G. cells of kidney promoting erythropoiesis. Hint : Origin of replication. Interleukins are lymphokines that activate immune system. Sol. : Plasmids are extra-chromosomal DNA. They replicate autonomously and are one of the most 178. Answer (1) commonly used cloning vectors. Hint : It is considered as salt retaining hormone 172. Answer (3) Sol. : The gene for human growth hormone (hGH) Hint : Selectable marker helps in eliminating the was isolated from human pituitary gland. E. coli is non-transformants. used in recombinant DNA technology for Sol. : Purified DNA precipitates out after the pharmaceutical manufacturing of insulin. addition of chilled ethanol. Plasmids are 179. Answer (4) extrachromosomal double stranded circular DNA in Hint : Identify a super bug. bacteria. Sol. : Bioremediation is a strategy that uses 173. Answer (1) naturally occurring organisms to breakdown Hint : pBR322 has unique restriction site for certain pollutants, such as petroleum hydrocarbons endonucleases. into less toxic substances. Bioremediation by Sol. : Unique restriction site for Sal I is present in Pseudomonas aeruginosa is also well documented. tetra cycline resistance gene. 180. Answer (3) 174. Answer (1) Hint : Stealing of patent. Hint : An expensive technique for treatment of Sol. : Biopiracy is the term used to refers to the use genetic disease. of bio-resources by multinational companies and Sol. : Gene therapy is an expensive technique that other organisations without proper authorisation uses genes to treat or prevent disease. In the future, from the countries and people concerned with this technique may allow doctors to treat a disorder compensatory payment.
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