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3 questions

When gene targetting involving gene amplification is attempted in an individual’s tissue to treat disease, it is known as : Answer: 2. Gene therapy Treating a disease by correcting a defective gene, by delivering a normal gene into a person's cells and tissues, is... Applications in health: human insulin, vaccines, gene therapy 1 answer
The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which, during pollination, brings genetically different types of pollen grains to stigma, is : Answer: 1. Xenogamy Pollen transfer from the anther of one plant to the stigma of a genetically different plant is xenogamy, and it brings g... Pollination: types, agencies, examples 1 answer
Which of the following is a correct sequence of steps in a PCR (Polymerase Chain Reaction) ? Answer: 1. Denaturation, Annealing, Extension Each PCR cycle has three steps in order: denaturation (double strand separated at about 94 °C)... Processes of recombinant DNA technology 1 answer
The amount of nutrients, such as carbon, nitrogen, phosphorus and calcium present in the soil at any given time, is referred as : Answer: 3. Standing state The amount of nutrients such as C, N, P and Ca present in the soil at a given time is the standing state. Standing... Ecosystem patterns and components 1 answer
The first stable product of CO_2 fixation in sorghum is : Answer: 2. Oxaloacetic acid Sorghum is a C4 plant. Its mesophyll cells fix CO ₂ with PEP carboxylase, so the first stable product is a 4-car... C3 and C4 pathways, photorespiration 1 answer
In the equation GPP-R=NPPR represents : Answer: 4. Respiration losses Net primary productivity is gross primary productivity minus the energy used by plants in respiration. So NPP... Productivity and decomposition 1 answer
Gemmae are present in : Answer: 4. Some Liverworts Gemmae are small green multicellular buds that form in gemma cups on the thallus. They are a means of asexual rep... Plant kingdom: algae, bryophytes, pteridophytes, gymnosperms 1 answer
The incorrect statement among the following is : Answer: 2. Most of the trivalent Lanthanoid ions are colorless in the solid state. Key idea: compare f-block properties. Actinoid contractio... Lanthanoids and lanthanoid contraction 1 answer
The RBC deficiency is deficiency disease of : Answer: 1. Vitamin B₁₂ Key idea: vitamin mathrmB₁₂ is needed for red blood cell formation. Its deficiency causes pernicious anaemia (reduced... Vitamins 1 answer
Tritium, a radioactive isotope of hydrogen, emits which of the following particles ? Answer: 1. Beta ( β^- ) Key idea: tritium ( ³₁H ) is a beta emitter. ³₁H→³₂He+β^-+barν : a neutron changes into a proton, emitting a β^- par... Atomic and molecular masses, mole concept, molar mass 1 answer
Match List - I with List - II.List - I : (a) 2SO_2(g) + O_2(g) → 2SO_3(g) (b) HOCl(g) h OH + Cl (c) CaCO_3 + H_2SO_4 → CaSO_4 + H_2O + CO_2 (d) NO_2(g) h NO(g) + O(g)List - II : (i) Acid rain (ii) Smog (iii) Ozone depletion (iv) Tropospheric pollutio… Answer: 3. (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii) Key idea: identify each reaction with its environmental context. (a) SO₂ oxidised to SO₃ i... Types of organic reactions 1 answer
CH_3CH_2COO^-Na^+ [Heat]NaOH,\ +\ ? CH_3CH_3 + Na_2CO_3.Consider the above reaction and identify the missing reagent/chemical. Answer: 3. CaO Key idea: decarboxylation of a sodium carboxylate with soda lime. mathrmCH₃CH₂COONa+NaOHxrightarrowCaO,\ ΔCH₃CH₃+Na₂CO₃ . The... Classification, isomerism, nomenclature, preparation 1 answer
The product formed in the following chemical reaction is :2-(methyl-substituted) cyclohexanone bearing CH_2-C(=O)-OCH_3 and CH_3 groups [C_2H_5OH]NaBH_4 ? Answer: 4. Cyclohexane ring with OH, CH₃ and CH₂-C(=O)-OCH₃ substituents Key idea: NaBH₄ is a mild reducing agent. It reduces aldehydes and... Aldehydes and ketones: HCN, NH3 derivatives, Grignard, oxidation, reduction (Wolff-Kishner, Clemmensen) 1 answer
Match List - I with List - II.List - I : (a) [Fe(CN)_6]^3- (b) [Fe(H_2O)_6]^3+ (c) [Fe(CN)_6]^4- (d) [Fe(H_2O)_6]^2+List - II : (i) 5.92 BM (ii) 0 BM (iii) 4.90 BM (iv) 1.73 BMChoose the correct answer from the options given below. Answer: 4. (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii) Key idea: find unpaired electrons n and use μ=√(n(n+2)) BM. (a) mathrm[Fe(CN)₆]³⁻ : mathrm... Crystal field theory, colour and magnetic properties 1 answer
From the following pairs of ions which one is not an iso-electronic pair ? Answer: 4. Fe²⁺, Mn²⁺ Key idea: iso-electronic species have the same number of electrons. mathrmO²⁻ (10) and F^- (10): yes Na^+ (10) and mat... Atomic and ionic radii 1 answer
The reagent 'R' in the given sequence of chemical reaction is :2,4,6-tribromoaniline NaNO_2, HCl,\ 0-5^° C 2,4,6-tribromobenzenediazonium chloride R 1,3,5-tribromobenzene Answer: 2. CH₃CH₂OH Key idea: replacing the diazonium group by hydrogen (hydro-de-diazoniation) needs a mild reducing agent. Ethanol (or H₃P... Diazonium salts in synthesis 1 answer
Choose the correct option for the total pressure (in atm.) in a mixture of 4 g O_2 and 2 g H_2 confined in a total volume of one litre at 0^° C is :[Given R=0.082 L atm mol^-1K^-1, T=273 K] Answer: 3. 25.18 Key idea: PV=nRT with total moles of gas. n_(O_2)=4/32=0.125 ; n_(H_2)=2/2=1 ; total = 1.125 mol. P=nRT/V=1.125×0.082×273/1... Atomic and molecular masses, mole concept, molar mass 1 answer
Which of the following molecules is non-polar in nature ? Answer: 3. SbCl₅ Key idea: a molecule is non-polar if its bond dipoles cancel by symmetry. SbCl₅ is a symmetric trigonal bipyramid with no l... Electronegativity, Fajan's rule, dipole moment 1 answer
In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it ? Answer: 2. H₂O < H₂S < H₂Se < H₂Te : Increasing pK_a values Key idea: check each trend. 1: acidic strength HF < HCl < HBr < HI is correct (w... Valence, oxidation states and chemical reactivity 1 answer
The correct option for the value of vapour pressure of a solution at 45^° C with benzene to octane in molar ratio 3 : 2 is :[At 45^° C vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg. Assume Ideal gas] Answer: 3. 336 mm of Hg Key idea: Raoult's law for an ideal solution: P=x₁P₁^°+x₂P₂^° . x_benzene=3/5=0.6 , x_octane=2/5=0.4 . P=0.6(280)+0.... Vapour pressure and Raoult's law 1 answer
The molar conductivity of 0.007 M acetic acid is 20 S cm^2 mol^-1. What is the dissociation constant of acetic acid ? Choose the correct option.^°_H^+ = 350 S cm^2 mol^-1, ^°_CH_3COO^- = 50 S cm^2 mol^-1 Answer: 3. 1.75×10⁻⁵ mol L ⁻¹ Key idea: α=Lambda_m/Lambda^°_m , and K_a=Cα²/1-α≈ Cα² . Lambda^°=350+50=400 ; α=20/400=0.05 . K_a≈0.007×(0.05... Conductance, molar conductivity and its variation with concentration 1 answer
The slope of Arrhenius Plot ( k v/s 1/T) of first order reaction is -5×10^3 K. The value of E_a of the reaction is. Choose the correct option for your answer.[Given R=8.314 J K^-1mol^-1] Answer: 1. 41.5 kJ mol ⁻¹ Key idea: Arrhenius equation ln k=ln A-E_a/RT ; slope of ln k vs 1/T is -E_a/R . E_a=-slope× R=5×10³×8.314=41570\... Effect of temperature, Arrhenius equation, activation energy 1 answer
Match List - I with List - II.List - I : (a) benzene [Anhyd. AlCl_3/CuCl]CO,\ HCl (b) R-CO-CH_3 + NaOX → (c) R-CH_2-OH + R'COOH Conc. H_2SO_4 (d) R-CH_2COOH [(ii) H_2O](i) X_2/Red PList - II : (i) Hell-Volhard-Zelinsky reaction (ii) Gattermann-Koch r… Answer: 4. (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i) Key idea: match each reaction with its name. (a) benzene + CO, HCl, anhydrous AlCl₃ /CuCl:... Aldehydes and ketones: HCN, NH3 derivatives, Grignard, oxidation, reduction (Wolff-Kishner, Clemmensen) 1 answer
The intermediate compound 'X' in the following chemical reaction is :toluene + CrO_2Cl_2 CS_2 X H_3O^+ benzaldehyde Answer: 1. C₆H₅-CH(OCrOHCl₂)₂ Key idea: this is the Etard reaction: toluene is partially oxidised to benzaldehyde by chromyl chloride. Tolue... Aldehydes and ketones: HCN, NH3 derivatives, Grignard, oxidation, reduction (Wolff-Kishner, Clemmensen) 1 answer

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