CEE Mock 1, on paper

1. Stanley Miller and Harold Urey passed electric sparks through a gas mixture meant to model the early Earth's atmosphere. Which mixture did they use?

2. Which pair of structures points to common ancestry rather than to adaptation for a similar way of life?

3. Before an insecticide was first sprayed in a district, a few mosquitoes there already carried a gene for resistance to it. After years of spraying, most mosquitoes in the district are resistant. Which explanation fits this best?

4. A water vascular system, which works the tube feet used in locomotion, is a diagnostic feature of which phylum?

5. Flame cells are the excretory structures characteristic of which phylum?

6. A body cavity that is lined by mesoderm only on its outer side, with the endoderm of the gut forming its inner boundary, is found in

7. A specimen has jaws, a cartilaginous endoskeleton, placoid scales, a ventral mouth and separate gill slits with no operculum over them. In which class should it be placed?

8. In a myelinated nerve fibre of the peripheral nervous system, the myelin sheath is formed by

9. Intercalated discs are a distinguishing feature of

10. Damaged articular cartilage, which covers the ends of bones at joints, heals far more slowly than bone. The main reason is that cartilage

11. A tissue section shows a single layer of cells whose nuclei lie at different heights, so it looks layered, though every cell rests on the basement membrane. The free surface bears cilia, with goblet cells scattered among the cells. The sample most likely came from the

12. In the life cycle of Plasmodium vivax, fertilisation of the gametes takes place in the

13. A patient with malaria has bouts of chills and fever that return every 72 hours. Which species is most likely to be the cause?

14. In the earthworm Pheretima, the clitellum, the glandular band that secretes the cocoon, covers segments

15. In Pheretima, the dorsal wall of the intestine is folded into the cavity as the typhlosole from segment 26 onwards. What does this fold chiefly do?

16. During hibernation, while it lies buried in mud, the frog Rana respires mainly through its

17. A tadpole excretes mostly ammonia, but the adult frog excretes mostly urea. What best explains this change?

18. Which enzyme, secreted in an inactive form and activated by hydrochloric acid, begins the digestion of proteins in the human stomach?

19. Bile contains no digestive enzymes, yet without it fats are digested poorly. Why?

20. Most of the carbon dioxide carried in human blood travels in the form of

21. During hard exercise, working muscle becomes warmer and produces more CO₂ and acid. How do these changes affect the oxygen–haemoglobin dissociation curve, and with what result?

22. In the human heart, the impulse that starts each heartbeat normally arises in the

23. A resting adult has a heart rate of 72 beats per minute and a stroke volume of 70 mL. What is the cardiac output?

24. A patient of blood group B, Rh-negative, needs a transfusion of red cells, and no B-negative blood is available. Which donor's red cells can be given safely?

25. In a healthy nephron, nearly all the glucose in the glomerular filtrate is reabsorbed in the

26. After a long walk in the sun without drinking, a person passes a small volume of dark, concentrated urine. Which action of antidiuretic hormone (ADH) explains this?

27. During the rising (depolarisation) phase of an action potential, the inside of a neuron becomes positive. What causes this?

28. Which part of the human brain coordinates voluntary movements and maintains balance and posture?

29. The organ of Corti, whose hair cells turn sound vibrations into nerve impulses, lies in the

30. Cretinism, with stunted growth and impaired mental development, results from a deficiency in infancy and childhood of which hormone?

31. In a human female, a primary oocyte completes meiosis I shortly before ovulation. When does the resulting secondary oocyte complete meiosis II?

32. If an ovulated egg is not fertilised, menstruation follows about two weeks later. What directly triggers the breakdown of the uterine lining?

33. Which of these diseases is caused by a fungus?

34. The collapse of immunity in AIDS is mainly due to HIV destroying which cells?

35. Why are live attenuated vaccines, such as BCG and the measles vaccine, avoided in people whose immunity is severely weakened?

36. Someone bitten by a dog that may be rabid is injected with ready-made anti-rabies antibodies (immunoglobulin) as well as the vaccine. What kind of immunity do the injected antibodies themselves give?

37. Amniocentesis, in which a little amniotic fluid is drawn from the uterus during pregnancy, is used mainly to

38. During secondary treatment of sewage, the BOD of the waste water falls sharply in the aeration tank. What is the main reason?

39. Which wetland became Nepal's first Ramsar site, in 1987?

40. A lake receives DDT washed in from nearby fields. Which organisms in its food chain would show the highest concentration of DDT in their body tissues?

41. In maltose, the two glucose units are joined by which bond?

42. Malonic acid slows the conversion of succinate to fumarate by succinate dehydrogenase, but the slowing almost disappears when succinate is added in large excess. Malonic acid is acting as:

43. The three-domain system divides living organisms into Bacteria, Archaea and Eukarya mainly on the basis of differences in their:

44. In Gram staining, Gram-positive bacteria keep the crystal violet stain after the alcohol wash because their cell wall has:

45. The genetic material of tobacco mosaic virus (TMV) is:

46. In Mucor, sexual reproduction by fusion of gametangia from two compatible (+ and −) hyphae produces a thick-walled:

47. Which statement about the life cycle of Spirogyra is correct?

48. The gemmae produced in the gemma cups on the thallus of Marchantia serve for:

49. In Pinus, the endosperm of the seed is:

50. A flower is actinomorphic and bisexual, with five united sepals, five united petals, five stamens fused to the corolla, and a superior bicarpellary ovary placed obliquely, with swollen axile placentae. It belongs to the family:

51. Reserpine, an alkaloid used to lower high blood pressure, is obtained mainly from the roots of:

52. In a hydrosere developing in a pond, the pioneer community is made up of:

53. In a pond, the pyramid of biomass is often inverted. The best explanation is that phytoplankton:

54. A farmer's field stays waterlogged for weeks and its soil becomes poorly aerated. The nitrate content of the soil falls sharply. The process mainly responsible is:

55. In Nepal, forests dominated by sal (Shorea robusta) are characteristic of the:

56. During cytokinesis in a plant cell, the cell plate is formed by the fusion of vesicles supplied mainly by the:

57. Mitochondria and chloroplasts are described as semi-autonomous organelles because they:

58. Crossing over between non-sister chromatids of homologous chromosomes takes place during which sub-stage of prophase I?

59. A plant has 2n = 24. How many chromatids are present in one cell at metaphase I of meiosis, and how many chromosomes are in each daughter cell at the end of meiosis I?

60. Which event happens in anaphase I of meiosis and distinguishes it from anaphase of mitosis?

61. That DNA replicates semiconservatively was first shown by experiment, using heavy nitrogen (¹⁵N), by:

62. Two pea plants, each heterozygous for two unlinked genes (AaBb), are crossed. What fraction of the offspring will show both dominant traits and also breed true for both?

63. Flower colour in Mirabilis jalapa (four o'clock plant) shows incomplete dominance between red and white. A pink-flowered plant is crossed with a white-flowered plant. The offspring are expected in the ratio:

64. A woman with normal colour vision, whose father was colour-blind, marries a colour-blind man. What proportion of their daughters is expected to be colour-blind?

65. A person with the karyotype 44 autosomes + XO (45 chromosomes in all) has:

66. Genes A and B lie on the same chromosome and show 8% recombination; genes A and C show 30% recombination. Which conclusion is correct?

67. Vascular bundles that are conjoint, collateral and closed, and lie scattered through the ground tissue, are characteristic of the:

68. A transverse section shows xylem and phloem on alternate radii, protoxylem towards the outside, about twelve xylem strands and a large, well-developed pith. It is most likely from a:

69. Which tissue is made of living cells whose walls are thickened unevenly at the corners with cellulose and pectin, giving flexible support to young stems and petioles?

70. A plant cell has a solute potential of −0.9 MPa and a pressure potential of +0.3 MPa. It is placed in a sucrose solution whose water potential is −0.8 MPa. What happens?

71. In C₄ plants such as maize, the first stable product of CO₂ fixation in the mesophyll cells is:

72. Photorespiration is negligible in C₄ plants such as sugarcane mainly because:

73. Oxidative decarboxylation of one pyruvate molecule to acetyl-CoA, followed by one complete turn of the Krebs cycle, releases how many molecules of CO₂?

74. When the shoot tip of a plant is cut off, the lateral buds below it start to grow. This is because the shoot tip was the main source of:

75. In which of these seeds is germination epigeal, with the cotyledons carried above the soil?

76. A typical (Polygonum-type) embryo sac of an angiosperm, at maturity, is:

77. In an angiosperm with 2n = 14, what are the chromosome numbers of the endosperm and of the egg cell?

78. A nursery wants virus-free plants of a banana variety whose whole stock is infected with a virus. Which explant should it culture?

79. In paddy fields, the water fern Azolla is used as a biofertiliser because it houses a nitrogen-fixing symbiont in its leaf cavities. The symbiont is:

80. In genetic engineering, the enzyme used to cut DNA at a specific base sequence is:

81. 4.0 g of hydrogen gas is sparked with 16.0 g of oxygen gas. What mass of water is formed? (H = 1, O = 16)

82. The lines of the Balmer series in the hydrogen spectrum are produced when the electron drops from a higher orbit to the orbit with

83. How many unpaired electrons does a ground-state Fe³⁺ ion (Z = 26) have?

84. Which of these isoelectronic ions has the smallest radius?

85. According to VSEPR theory, what is the shape of the ClF₃ molecule?

86. How many σ and π bonds does a molecule of ethyne, C₂H₂, contain?

87. A fixed amount of an ideal gas occupies 600 mL at 27 °C and 1 atm. At what temperature will it occupy 400 mL at 2 atm?

88. How many Bravais lattices are possible across the seven crystal systems?

89. For the reaction N₂(g) + 3H₂(g) ⇌ 2NH₃(g), how are Kp and Kc related?

90. What volume of 0.2 N NaOH solution is needed to neutralise 25 mL of 0.1 M H₂SO₄?

91. 50 mL of 0.10 M HCl is mixed with 50 mL of 0.06 M NaOH. What is the pH of the mixture? (log 2 = 0.30)

92. Which salt gives an acidic solution when dissolved in water?

93. A first-order reaction has a half-life of 20 min. How long does it take for 87.5% of the reactant to be used up?

94. A current of 9.65 A is passed through aqueous CuSO₄ for 2000 s. What mass of copper is deposited at the cathode? (Cu = 63.5, F = 96500 C mol⁻¹)

95. The enthalpies of combustion of graphite, hydrogen and methane are −394, −286 and −891 kJ mol⁻¹ respectively. What is the enthalpy of formation of methane?

96. When a nucleus emits a β⁻ particle, what happens to its atomic number and mass number?

97. What is the oxidation number of chromium in K₂Cr₂O₇?

98. Which oxide is amphoteric, reacting with both dilute HCl and NaOH solution?

99. Chlorofluorocarbons broken apart by ultraviolet light in the stratosphere release a species that destroys ozone in a chain reaction. Which species is it?

100. Sulphur dioxide bleaches moist coloured matter, but the colour slowly returns on standing in air. This is because SO₂ bleaches by

101. In the blast-furnace extraction of iron, which substance is added as a flux to remove the silica gangue as slag?

102. Which ore is converted into its oxide by calcination (heating in the absence or a limited supply of air) rather than by roasting?

103. Sodium burns in excess air. What is the main product?

104. In an octahedral crystal field, which d orbitals form the higher-energy eg set?

105. What is the spin-only magnetic moment of the Cr³⁺ ion (Z = 24)?

106. What is the chemical formula of corrosive sublimate?

107. Itai-itai disease, which softens the bones and damages the kidneys, results from chronic poisoning by

108. What is the IUPAC name of (CH₃)₂CH–CH₂–COOH?

109. Which of the following species acts as a nucleophile?

110. How many structural isomers, counting alcohols and ethers together, have the molecular formula C₄H₁₀O? (Ignore stereoisomers.)

111. Which compound is the reference fuel assigned an octane number of 100?

112. Propene reacts with HBr in the presence of benzoyl peroxide. What is the major product?

113. Which hydrocarbon gives a white precipitate with ammoniacal silver nitrate solution?

114. In the nitration of benzene with a mixture of concentrated nitric and sulphuric acids, which electrophile attacks the ring?

115. Which alkyl bromide is hydrolysed fastest by the SN1 mechanism?

116. Chloroform is stored in dark bottles filled to the top because air and light slowly oxidise it to a poisonous gas. Which gas?

117. What volume of hydrogen at STP is released when 4.6 g of ethanol reacts completely with excess sodium? (C = 12, H = 1, O = 16; molar volume at STP = 22.4 L)

118. Phenol is a stronger acid than ethanol. What is the main reason?

119. Which pair of reagents gives the best yield of tert-butyl methyl ether, (CH₃)₃C–O–CH₃, by Williamson's synthesis?

120. Which aldehyde undergoes the Cannizzaro reaction when warmed with concentrated sodium hydroxide?

121. What is the correct order of reactivity of acid derivatives toward nucleophilic acyl substitution?

122. Nitrobenzene is reduced with tin and concentrated hydrochloric acid, and the mixture is then made alkaline. What is the organic product?

123. In Hoffmann's method for separating a mixture of primary, secondary and tertiary amines, the mixture is treated with

124. Methylmagnesium bromide reacts with acetone in dry ether, and the product is hydrolysed with dilute acid. Which alcohol is formed?

125. Plaster of Paris, which sets to a hard mass when mixed with water, has the formula

126. Which of these polymers is formed by condensation polymerisation?

127. In the Contact process, SO₃ is absorbed in concentrated H₂SO₄ rather than directly in water. Why?

128. In Lassaigne's test, the sodium fusion extract of a compound containing nitrogen but no sulphur is boiled with FeSO₄ solution and then acidified. Nitrogen is shown by

129. Glycerol decomposes before it reaches its boiling point at atmospheric pressure. How is it best purified?

130. Which indicator should be used when acetic acid is titrated against sodium hydroxide solution?

131. The coefficient of viscosity η is defined by F = ηA(dv/dx). What is its dimensional formula?

132. A ball is thrown vertically upwards and falls back into the thrower's hand. If air resistance is negligible, which quantity stays the same throughout the flight?

133. What is the moment of inertia of a thin uniform rod of mass M and length L about an axis through its centre, perpendicular to its length?

134. By Stokes' law, a small sphere of radius r moving at a steady speed v through a fluid of viscosity η experiences a viscous drag of

135. The escape velocity from the surface of the Earth is independent of

136. Poisson's ratio of a stretched wire is the ratio of

137. A particle is performing simple harmonic motion. At its mean (equilibrium) position,

138. Water rises to a height h in a clean glass capillary tube of radius r. To what height does it rise in a tube of the same glass of radius r/2, at the same temperature?

139. A 2 kg ball moving at 6 m s⁻¹ hits a stationary 1 kg ball, and the two stick together. How much kinetic energy is lost in the collision?

140. A bucket of water is swung in a vertical circle of radius 0.9 m. What is the least speed it must have at the top of the circle so that the water does not fall out? (g = 10 m s⁻²)

141. Which thermometer is suited to measuring the temperature of a furnace at about 2000 °C without touching it?

142. For an isotropic solid whose coefficient of linear expansion is α, the coefficient of cubical (volume) expansion is

143. A thermodynamic process in which no heat enters or leaves the system is called

144. The absolute temperature of a black body is doubled, its size staying the same. By what factor does the power it radiates increase?

145. The absolute temperature of an ideal gas is raised from T to 4T. The rms speed of its molecules becomes

146. How much heat is needed to turn 0.1 kg of ice at 0 °C into water at 20 °C? (Latent heat of fusion of ice = 3.36 × 10⁵ J kg⁻¹; specific heat capacity of water = 4200 J kg⁻¹ K⁻¹)

147. A Carnot engine takes in heat at 227 °C and rejects heat at 27 °C. What is its efficiency?

148. The speed of sound in an ideal gas is directly proportional to

149. An air column in a pipe closed at one end and open at the other can produce

150. Brewster's law relates the polarising angle θₚ of a surface to the refractive index μ of the medium (light incident from air). It states that

151. μᵥ, μᵣ and μ are the refractive indices of a glass for violet, red and mean (yellow) light. The dispersive power of the glass is

152. In Young's double-slit experiment, the separation between the slits is doubled and the distance from the slits to the screen is halved. The fringe width becomes

153. Sound from a room is easily heard round the edge of an open doorway, but light from the room does not bend round it noticeably. Why?

154. A source emitting sound of 450 Hz moves at 34 m s⁻¹ straight towards a stationary listener. What frequency does the listener hear? (Speed of sound = 340 m s⁻¹)

155. An object is placed 30 cm in front of a thin convex lens of focal length 20 cm. Where is the image formed?

156. Kirchhoff's current law (the junction rule) is a statement of the conservation of

157. To convert a galvanometer into an ammeter, one connects

158. The two junctions of a thermocouple are kept at different temperatures, and an emf appears in the circuit. This is called the

159. The relative permeability of a diamagnetic substance such as bismuth is

160. The iron core of a transformer is built from thin insulated sheets (laminations) mainly to reduce

161. A potentiometer is preferred to a voltmeter for measuring the emf of a cell because

162. In a series LCR circuit driven at its resonant frequency, the current and the applied voltage are

163. The current in a long solenoid is doubled and, at the same time, its number of turns per metre is halved. The magnetic field inside it

164. In a metre bridge, a 6 Ω resistor is in the left gap and an unknown resistor R in the right gap. The null point is 40 cm from the left end of the wire. What is R?

165. A charge q is enclosed by a closed surface in vacuum. By Gauss's law, the total electric flux through the surface is

166. An air-filled parallel-plate capacitor has capacitance C. When the space between its plates is completely filled with a dielectric of dielectric constant K, its capacitance becomes

167. Two point charges repel each other with a force F. If each charge is doubled and the distance between them is also doubled, the force becomes

168. Capacitors of 3 μF and 6 μF are connected in series across a 12 V battery. What is the potential difference across the 3 μF capacitor?

169. Fission of a uranium-235 nucleus and fusion of light nuclei such as deuterium both release energy. The reason is that, in each case,

170. An electron enters a uniform magnetic field with its velocity perpendicular to the field. Ignoring gravity, it moves in

171. In the photoelectric effect, the maximum kinetic energy of the emitted electrons depends on

172. Light of wavelength 400 nm falls on a metal whose work function is 2.1 eV. What is the stopping potential? (Take hc = 1240 eV nm.)

173. Which series of the hydrogen spectrum has lines in the visible region?

174. An electron and a proton have the same kinetic energy. Which has the longer de Broglie wavelength?

175. In a Coolidge X-ray tube, the intensity of the X-rays is set by the filament current. What sets their penetrating power?

176. The activity of a radioactive sample falls from 1600 to 100 decays per minute in 16 hours. What is its half-life?

177. Which of the following has the greatest ionising power in air?

178. Pure silicon is made into an n-type semiconductor by doping it with a small amount of

179. Which two-input logic gate gives an output of 1 only when both inputs are 0?

180. In the quark model, a proton is made of

181. In a certain code, PATAN is written as QBUBO. How is BIRAT written in the same code?

182. Pointing to a girl, Ramesh says, 'Her mother is the only daughter of my father.' How is the girl related to him?

183. From his house, Bikash walks 4 km east, turns left and walks 3 km, then turns left again and walks 8 km. How far is he from his house, and in which direction?

184. Anu, Bina, Chetan, Dipak and Esha sit in a row facing north. Anu is at the extreme left and Chetan is in the middle. Dipak sits immediately to Chetan's right. Bina does not sit next to Anu. Who sits at the extreme right?

185. Statements: All doctors are graduates. Some graduates are singers. Conclusions: I. Some doctors are singers. II. Some graduates are doctors. Taking the statements as true, which conclusion follows?

186. If 35% of a number is 63, what is the number?

187. The average of five numbers is 18. If the number 26 is removed, what is the average of the remaining four?

188. A bus travels 120 km between two towns at 30 km/h and returns along the same road at 60 km/h. What is its average speed for the round trip?

189. The ratio of Asha's age to her mother's age is 1 : 4. Six years from now the ratio will be 2 : 5. How old is Asha now?

190. At simple interest, a sum of money becomes 1.5 times itself in 4 years. At the same rate, in how many years will it become three times itself?

191. What number comes next in the series 4, 9, 19, 39, 79, …?

192. Which letter comes next: C, G, K, O, …?

193. Find the next term: 2B, 4E, 8H, 16K, …

194. What number comes next: 4, 9, 8, 13, 16, 17, 32, …?

195. Find the next number: 3, 4, 8, 17, 33, …

196. A mirror is held upright along the dashed line, to the right of the figure. Which option shows the figure's mirror image?

197. In this series the arrow turns through the same angle at each step. Which option replaces the question mark?

198. How many triangles are there in the figure?

199. A square sheet is folded in half, left side over the right, then in half again, top over the bottom. One hole is punched through all the layers as shown. Which option shows the sheet when it is unfolded?

200. The net is folded into a cube with the numbers on the outside. Which option shows a view of that cube?