AIPMT 2005 Prelims Question PaperPhysics, Chemistry and Biology, with checked answers and solutions
By the RankUp team, founded by Dr. Deepak Sahu (MBBS Gold Medalist, NEET PG AIR 1731) · Updated
170 questions from the AIPMT 2005 Prelims paper, conducted by CBSE. Tap an option to check your answer and read why it is right. Each subject has a free PDF with the answer key and explanations.
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- AIPMT 2005 Prelims
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- 39 questions
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AIPMT 2005 Prelims Physics questions
35 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q1
A coil in the shape of an equilateral triangle of side l is suspended between the pole pieces of a permanent magnet such that B⃗ is in plane of the coil. If due to a current i in the triangle a torque τ acts on it, the side l of the triangle is :
Not quite — the answer is C.
With B in the plane of the coil the torque is maximum: τ = iAB with A = (√3/4)l². So l² = 4τ/(√3 Bi) and l = 2(τ/(√3 Bi))^(1/2). The trap (2/√3)(τ/Bi)^(1/2) wrongly keeps √3 outside the square root.
Q2AIPMT 2005 Prelims · Q3
A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distance of 2m and 3m respectively from the source. The ratio of the intensities of the waves at P and Q is :
Not quite — the answer is A.
A point source spreads energy over a sphere, so I ∝ 1/r². I_P/I_Q = (3/2)² = 9/4, i.e. 9 : 4. Writing 4 : 9 inverts the ratio by taking I ∝ r².
Q3AIPMT 2005 Prelims · Q4
A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 m s⁻¹. The kinetic energy of the other mass is :
Not quite — the answer is B.
Momentum conservation from rest: 18 × 6 = 12 × v, so v = 9 m/s. KE = ½ × 12 × 81 = 486 J. 243 J is half the correct value.
Q4AIPMT 2005 Prelims · Q6
Imagine a new planet having the same density as that of earth but it is 3 times bigger than the earth in size. If the acceleration due to gravity on the surface of earth is g and that on the surface of the new planet is g', then :
Not quite — the answer is A.
g = GM/R² = (4/3)πGρR, so at equal density g ∝ R. A planet with 3 times the radius has g' = 3g. g/9 would follow only if the mass stayed the same.
Q5AIPMT 2005 Prelims · Q8
Which of the following circular rods, (given radius r and length l) each made of the same material and whose ends are maintained at the same temperature will conduct most heat ?
Not quite — the answer is B.
Heat current H = kAΔT/l ∝ r²/l. For r = 2r₀, l = l₀ this is 4r₀²/l₀, the largest; r = 2r₀, l = 2l₀ gives only 2r₀²/l₀.
Q6AIPMT 2005 Prelims · Q9
In the reaction ²₁H + ³₁H → ⁴₂He + ¹₀n, if the binding energies of ²₁H, ³₁H and ⁴₂He are respectively a, b and c (in MeV), then the energy (in MeV) released in this reaction is :
Not quite — the answer is B.
Energy released = total binding energy of products − total binding energy of reactants = c − (a + b). The free neutron has zero binding energy. a + b − c has the sign reversed.
Q7AIPMT 2005 Prelims · Q11
Energy levels A, B and C of a certain atom correspond to increasing values of energy i.e., E_A < E_B < E_C. If λ₁, λ₂ and λ₃ are wavelengths of radiations corresponding to transitions C to B, B to A and C to A respectively, which of the following relations is correct ?
Not quite — the answer is B.
Photon energies add: hc/λ₃ = hc/λ₁ + hc/λ₂, so 1/λ₃ = 1/λ₁ + 1/λ₂ and λ₃ = λ₁λ₂/(λ₁ + λ₂). Adding the wavelengths directly is wrong because energy, not wavelength, is additive.
Q8AIPMT 2005 Prelims · Q12
The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation, the metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are :
Not quite — the answer is C.
E = 12400/4100 ≈ 3.0 eV. This exceeds the work functions of A (1.92 eV) and B (2.0 eV) but not C (5 eV), so only A and B emit. 'All three' ignores that 5 eV > 3 eV.
Q9AIPMT 2005 Prelims · Q13
The nuclei of which one of the following pairs of nuclei are isotones ?
Not quite — the answer is A.
Isotones have the same neutron number N = A − Z. Se: 74 − 34 = 40; Ga: 71 − 31 = 40. The Sr pair are isotopes (same Z) and the Mo/Zr pair are isobars (same A).
Q10AIPMT 2005 Prelims · Q17
The circular motion of a particle with constant speed is :
Not quite — the answer is D.
Uniform circular motion repeats after every revolution, so it is periodic. It is not SHM, because SHM is motion along a line under a restoring force ∝ displacement; only the projection of circular motion is SHM.
Q11AIPMT 2005 Prelims · Q18
A particle executing simple harmonic motion of amplitude 5 cm has maximum speed of 31.4 cm/s. The frequency of its oscillation is :
Not quite — the answer is D.
v_max = Aω, so ω = 31.4/5 = 6.28 rad/s and f = ω/2π = 1 Hz. Taking 6.28 as the frequency or dividing wrongly gives 2 Hz or 0.5 Hz.
Q12AIPMT 2005 Prelims · Q19
The ratio of the dimensions of Planck's constant and that of the moment of inertia is the dimension of :
Not quite — the answer is A.
[h] = ML²T⁻¹ and [I] = ML², so [h/I] = T⁻¹, the dimension of frequency. Angular momentum has the dimensions of h itself, not h/I.
Q13AIPMT 2005 Prelims · Q20
Which of the following processes is reversible ?
Not quite — the answer is D.
A quasi-static isothermal compression can be retraced through the same equilibrium states, so it is reversible. Heat flow by conduction or radiation across a finite temperature difference and Joule heating are irreversible.
Q14AIPMT 2005 Prelims · Q22
A photosensitive metallic surface has work function, hν₀. If photons of energy 2hν₀ fall on this surface, the electrons come out with a maximum velocity of 4 × 10⁶ m/s. When the photon energy is increased to 5hν₀, then maximum velocity of photoelectrons will be :
Not quite — the answer is D.
KE_max = E − hν₀. With 2hν₀ it is hν₀; with 5hν₀ it is 4hν₀. Since v ∝ √KE, the speed doubles to 8 × 10⁶ m/s. 16 × 10⁶ m/s wrongly takes v ∝ KE.
Q15AIPMT 2005 Prelims · Q23
Fission of nuclei is possible because the binding energy per nucleon in them :
Not quite — the answer is B.
At high mass numbers the binding energy per nucleon falls as A increases, so splitting a heavy nucleus into medium nuclei raises the binding energy per nucleon and releases energy. Increase with A at low mass numbers explains fusion, not fission.
Q16AIPMT 2005 Prelims · Q25
The displacement x of a particle varies with time t as x = ae^(−αt) + be^(βt), where a, b, α and β are positive constants. The velocity of the particle will :
Not quite — the answer is D.
v = −aαe^(−αt) + bβe^(βt) and dv/dt = aα²e^(−αt) + bβ²e^(βt) > 0 for all t, so the velocity keeps increasing. It clearly depends on α and β, and α = β does not make it zero for all times.
Q17AIPMT 2005 Prelims · Q27
In any fission process the ratio (mass of fission products/mass of parent nucleus) is :
Not quite — the answer is A.
Fission releases energy Q = Δm c², which comes from a loss of mass, so the products are lighter than the parent nucleus and the ratio is less than 1. 'Equal to 1' ignores the mass defect.
Q18AIPMT 2005 Prelims · Q28
An ideal gas heat engine operates in Carnot cycle between 227°C and 127°C. It absorbs 6 × 10⁴ cal of heat at higher temperature. Amount of heat converted to work is :
Not quite — the answer is C.
η = 1 − T₂/T₁ = 1 − 400/500 = 0.2 (temperatures in kelvin). W = 0.2 × 6 × 10⁴ = 1.2 × 10⁴ cal. Using Celsius temperatures or the rejected heat (4.8 × 10⁴ cal) gives the wrong choices.
Q19AIPMT 2005 Prelims · Q29
If a vector 2î + 3ĵ + 8k̂ is perpendicular to the vector 4ĵ − 4î + αk̂, then the value of α is :
Not quite — the answer is C.
Perpendicular vectors have zero dot product: 2(−4) + 3(4) + 8α = 0, so 4 + 8α = 0 and α = −1/2. Ignoring the sign of the î component gives the wrong −2 or 2.
Q20AIPMT 2005 Prelims · Q32
A stone tied to the end of a string of 1 m long is whirled in a horizontal circle with a constant speed. If the stone makes 22 revolutions in 44 s, what is the magnitude and direction of acceleration of the stone ?
Not quite — the answer is C.
f = 22/44 = 0.5 rev/s, so ω = 2πf = π rad/s. a = ω²r = π² × 1 = π² m s⁻², directed along the radius towards the centre (centripetal). Acceleration of uniform circular motion is never tangential or outward.
Q21AIPMT 2005 Prelims · Q33
If the magnetic dipole moment of an atom of diamagnetic material, paramagnetic material and ferromagnetic material are denoted by μd, μp and μf respectively, then :
Not quite — the answer is C.
Atoms of diamagnetic substances have no net permanent dipole moment, while atoms of paramagnetic and ferromagnetic substances do. So μd = 0 and μp ≠ 0; any option with μd ≠ 0 or μp = 0 is wrong.
Q22AIPMT 2005 Prelims · Q34
In a circuit, L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by 45°. The value of C is :
Not quite — the answer is A.
Current leading the voltage means the circuit is net capacitive: tan 45° = (X_C − X_L)/R = 1, so X_C = X_L + R. 1/(2πfC) = 2πfL + R gives C = 1/[2πf(2πfL + R)]. The form with (2πfL − R) would come from X_C = X_L − R, which makes the circuit inductive with current lagging.
Q23AIPMT 2005 Prelims · Q36
Two vibrating tuning forks produce progressive waves given by y₁ = 4 sin 500πt and y₂ = 2 sin 506πt. Number of beats produced per minute is :
Not quite — the answer is B.
ω₁ = 500π gives f₁ = 250 Hz and ω₂ = 506π gives f₂ = 253 Hz. Beat frequency = 3 per second = 180 per minute. 360 per minute would double the true beat frequency of 3 Hz.
Q24AIPMT 2005 Prelims · Q37
When a wire of uniform cross-section a, length l and resistance R is bent into a complete circle, resistance between two of diametrically opposite points will be :
Not quite — the answer is A.
Each semicircle has resistance R/2 and the two halves are in parallel between diametrically opposite points: (R/2 × R/2)/(R/2 + R/2) = R/4. R/2 is the resistance of only one half.
Q25AIPMT 2005 Prelims · Q38
Carbon, silicon and germanium atoms have four valence electrons each. Their valence and conduction bands are separated by energy band gaps represented by (Eg)C, (Eg)Si and (Eg)Ge respectively. Which one of the following relationships is true in their case ?
Not quite — the answer is A.
Band gaps fall down group 14: carbon (diamond) ≈ 5.5 eV, Si ≈ 1.1 eV, Ge ≈ 0.7 eV. So (Eg)C > (Eg)Si; diamond is an insulator, not a material with a smaller gap.
Q26AIPMT 2005 Prelims · Q39
If λv, λx and λm represent the wavelengths of visible light, X-rays and microwaves respectively, then :
Not quite — the answer is C.
In the EM spectrum microwaves (mm–cm) are longer than visible light (400–700 nm), which is longer than X-rays (≈ 0.01–10 nm). So λm > λv > λx.
Q27AIPMT 2005 Prelims · Q40
Two boys are standing at the ends A and B of a ground, where AB = a. The boy at B starts running in a direction perpendicular to AB with velocity v₁. The boy at A starts running simultaneously with velocity v and catches the other boy in a time t, where t is :
Not quite — the answer is B.
The catcher runs along the hypotenuse of a right triangle with legs a and v₁t: (vt)² = a² + (v₁t)², so t = √(a²/(v² − v₁²)). a/(v − v₁) would apply only if both ran along the same line.
Q28AIPMT 2005 Prelims · Q41
A 5-A fuse wire can withstand a maximum power of 1 W in circuit. The resistance of the fuse wire is :
Not quite — the answer is D.
P = I²R, so R = P/I² = 1/25 = 0.04 Ω. Using P = IR gives 0.2 Ω.
Q29AIPMT 2005 Prelims · Q42
Two bodies have their moments of inertia I and 2I respectively about their axis of rotation. If their kinetic energies of rotation are equal, their angular momenta will be in the ratio :
Not quite — the answer is D.
E = L²/2I, so L = √(2IE). For equal E, L₁/L₂ = √(I/2I) = 1 : √2. The body with the larger moment of inertia has the larger angular momentum, not the smaller.
Q30AIPMT 2005 Prelims · Q43
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to :
Not quite — the answer is C.
The orbiting electron is a current I = ev/(2πr), giving B = μ₀I/(2r) = μ₀ev/(4πr²). So r² ∝ v/B and r ∝ √(v/B). v/B would follow from B ∝ v/r, which ignores that the current itself depends on r.
Q31AIPMT 2005 Prelims · Q44
Choose the only false statement from the following :
Not quite — the answer is D.
In a semiconductor more electrons cross the band gap as temperature rises, so conductivity increases and resistivity decreases. The statement that resistivity increases with temperature is therefore the false one; the other three are true.
Q32AIPMT 2005 Prelims · Q45
If the angle between the vectors A⃗ and B⃗ is θ, the value of the product (B⃗ × A⃗) · A⃗ is equal to :
Not quite — the answer is D.
B⃗ × A⃗ is perpendicular to A⃗, so its dot product with A⃗ is zero for any θ. The sin θ and cos θ forms wrongly treat the product as non-zero.
Q33AIPMT 2005 Prelims · Q46
The moment of inertia of a uniform circular disc of radius R and mass M about an axis passing from the edge of the disc and normal to the disc is :
Not quite — the answer is D.
About the central perpendicular axis I = MR²/2. By the parallel-axis theorem, about a parallel axis through the edge I = MR²/2 + MR² = (3/2)MR². (5/2)MR² wrongly adds 2MR².
Q34AIPMT 2005 Prelims · Q48
The total energy of an electron in the first excited state of hydrogen is about −3.4 eV. Its kinetic energy in this state is :
Not quite — the answer is D.
In a Bohr orbit KE = −E_total, so KE = +3.4 eV. Kinetic energy can never be negative, which rules out −3.4 eV and −1.7 eV.
Q35AIPMT 2005 Prelims · Q50
A ball is thrown vertically upward. It has a speed of 10 m/s when it has reached one half of its maximum height. How high does the ball rise ? (Taking g = 10 m/s²)
Not quite — the answer is B.
From H/2 to the top the speed drops from 10 m/s to 0: 10² = 2g(H/2) = gH, so H = 100/10 = 10 m. 5 m would be just the upper half.
Physics: not in the current NEET syllabus
These 5 questions are from topics NCERT dropped in its 2023 revision. Shown for completeness; you can skip them for NEET 2027.
5 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q5
A drum of radius R and mass M, rolls down without slipping along an inclined plane of angle θ. The frictional force :
Not quite — the answer is A.
In rolling without slipping the contact point is momentarily at rest, so static friction does no work and dissipates no heat. Its torque speeds up the rotation while it slows the translation, so it converts translational energy into rotational energy.
Q2AIPMT 2005 Prelims · Q21
The temperature of inversion of a thermocouple is 620°C and the neutral temperature is 300°C. what is the temperature of cold junction ?
Not quite — the answer is C.
The neutral temperature is the mean of the cold-junction and inversion temperatures: 300 = (θc + 620)/2, so θc = −20°C. Taking the difference instead of the mean gives 20°C.
Q3AIPMT 2005 Prelims · Q30
Zener diode is used for :
Not quite — the answer is C.
In reverse breakdown a Zener diode keeps a nearly constant voltage across itself over a wide range of current, so it is used as a voltage regulator (stabiliser). Rectification uses ordinary p-n diodes.
Q4AIPMT 2005 Prelims · Q35
The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 Å is of the order of :
Not quite — the answer is D.
Limit of resolution θ ≈ 1.22λ/D = 1.22 × 5 × 10⁻⁷/0.1 ≈ 6 × 10⁻⁶ rad, i.e. of the order of 10⁻⁶ rad. 10⁻⁴ rad would need a 1 mm aperture.
Q5AIPMT 2005 Prelims · Q47
Copper has face-centered cubic (fcc) lattice with interatomic spacing equal to 2.54 Å. The value of lattice constant for this lattice is :
Not quite — the answer is D.
In an fcc lattice atoms touch along the face diagonal, so the nearest-neighbour distance d = a/√2. a = √2 × 2.54 ≈ 3.59 Å. Taking a = d or dividing by √2 gives the smaller values.
Chapter-wise split of AIPMT 2005 Prelims Physics
- Nuclei4 Q
- Motion in a Plane4 Q
- Moving Charges and Magnetism2 Q
- Waves2 Q
- Atoms2 Q
- Dual Nature of Radiation and Matter2 Q
- Oscillations2 Q
- Thermodynamics2 Q
- Motion in a Straight Line2 Q
- Current Electricity2 Q
- Semiconductor Electronics: Materials, Devices and Simple Circuits2 Q
- System of Particles and Rotational Motion2 Q
- Laws of Motion1 Q
- Gravitation1 Q
- Thermal Properties of Matter1 Q
- Units and Measurements1 Q
- Magnetism and Matter1 Q
- Alternating Current1 Q
- Electromagnetic Waves1 Q
AIPMT 2005 Prelims Chemistry questions
35 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q51
Which amongst the following is the most stable carbocation ?
Not quite — the answer is B.
Carbocation stability is 3° > 2° > 1° > methyl because of hyperconjugation and the +I effect of alkyl groups. (CH₃)₃C⁺ is tertiary and most stable; the methyl cation is least stable.
Q2AIPMT 2005 Prelims · Q52
Products of the following reaction : CH₃C≡C·CH₂CH₃ —[(1) O₃, (2) Hydrolysis]→ ...... are :
Not quite — the answer is C.
Ozonolysis of an alkyne followed by hydrolysis cleaves the C≡C and gives carboxylic acids. Pent-2-yne CH₃C≡CCH₂CH₃ gives CH₃COOH + CH₃CH₂COOH. Aldehydes would form from an alkene, not an alkyne.
Q3AIPMT 2005 Prelims · Q54
Which one of the following pairs represents stereoisomerism ?
Not quite — the answer is D.
Stereoisomers have the same connectivity but different spatial arrangement; geometrical and optical isomerism are the two types. Chain, structural and linkage isomerism change connectivity.
Q4AIPMT 2005 Prelims · Q55
Aniline in a set of reactions yielded a product D. C₆H₅NH₂ —(NaNO₂/HCl)→ A —(CuCN)→ B —(H₂/Ni)→ C —(HNO₂)→ D The structure of the product D would be :
Not quite — the answer is D.
Aniline → benzenediazonium chloride → (CuCN) benzonitrile → (H₂/Ni) benzylamine C₆H₅CH₂NH₂ → (HNO₂) benzyl alcohol C₆H₅CH₂OH. Benzylamine is only intermediate C; nitrous acid converts this primary aliphatic amine to the alcohol.
Q5AIPMT 2005 Prelims · Q56
The correct order in which the O — O bond length increases in the following is :
Not quite — the answer is C.
O–O bond order: O₂ = 2, O₃ = 1.5 (resonance), H₂O₂ = 1. Bond length increases as bond order decreases, so O₂ < O₃ < H₂O₂.
Q6AIPMT 2005 Prelims · Q58
In a set of reactions, acetic acid yielded a product D. CH₃COOH —(SOCl₂)→ A —(Benzene, Anhyd. AlCl₃)→ B —(HCN)→ C —(HOH)→ D The structure of D would be :
Not quite — the answer is A.
CH₃COOH → (SOCl₂) CH₃COCl → (C₆H₆, AlCl₃) acetophenone C₆H₅COCH₃ → (HCN) cyanohydrin C₆H₅C(OH)(CH₃)CN → (hydrolysis) C₆H₅C(OH)(CH₃)COOH. The cyanohydrin is only C, and no CH₂ is inserted between ring and carbon.
Q7AIPMT 2005 Prelims · Q61
The number of moles of KMnO₄ reduced by one mole of KI in alkaline medium is :
Not quite — the answer is D.
In alkaline medium MnO₄⁻ → MnO₂ (gain 3e⁻) and I⁻ → IO₃⁻ (loss 6e⁻): 2MnO₄⁻ + I⁻ + H₂O → 2MnO₂ + IO₃⁻ + 2OH⁻. So one mole KI reduces two moles KMnO₄. 'One fifth' wrongly assumes MnO₄⁻ goes to Mn²⁺ (5 electrons) with I⁻ giving only 1 electron.
Q8AIPMT 2005 Prelims · Q62
Which of the following molecules has trigonal planar geometry ?
Not quite — the answer is D.
BF₃ has three bond pairs and no lone pair on boron (sp²), so it is trigonal planar. PCl₃ and NH₃ are pyramidal (one lone pair) and IF₃ is T-shaped (two lone pairs).
Q9AIPMT 2005 Prelims · Q63
The aqueous solution containing which one of the following ions will be colourless ? (Atomic no. : Sc = 21, Fe = 26, Ti = 22, Mn = 25)
Not quite — the answer is A.
Sc³⁺ is 3d⁰, so no d–d transition is possible and its solution is colourless. Ti³⁺ (3d¹), Mn²⁺ (3d⁵) and Fe²⁺ (3d⁶) have unpaired d electrons and are coloured.
Q10AIPMT 2005 Prelims · Q64
Four successive members of the first row transition elements are listed below with their atomic numbers. Which one of them is expected to have the highest third ionization enthalpy ?
Not quite — the answer is D.
The third electron of Mn is removed from Mn²⁺ (3d⁵), a stable half-filled configuration, so Mn has the highest third ionisation enthalpy. For Fe, removal from 3d⁶ gives the stable 3d⁵, so it is easier.
Q11AIPMT 2005 Prelims · Q65
Which one of the following compounds is most acidic ?
Not quite — the answer is B.
Phenols are more acidic than alcohols because the phenoxide ion is resonance-stabilised. The –NO₂ group withdraws electrons and further stabilises the phenoxide, so o-nitrophenol is most acidic; the –CH₃ of o-cresol lowers acidity.
Q12AIPMT 2005 Prelims · Q66
A reaction occurs spontaneously if :
Not quite — the answer is B.
ΔG = ΔH − TΔS. When ΔH and ΔS are both positive, ΔG < 0 only when TΔS > ΔH. With ΔH positive and ΔS negative, ΔG is always positive.
Q13AIPMT 2005 Prelims · Q68
The correct sequence of increasing covalent character is represented by :
Not quite — the answer is C.
By Fajans' rules, a smaller, more highly charged cation polarises Cl⁻ more. Polarising power Na⁺ < Li⁺ < Be²⁺, so covalent character NaCl < LiCl < BeCl₂.
Q14AIPMT 2005 Prelims · Q69
What is the correct relationship between the pHs of isomolar solutions of sodium oxide (pH₁), sodium sulphide (pH₂), sodium selenide (pH₃) and sodium telluride (pH₄) ?
Not quite — the answer is D.
These salts are basic by anion hydrolysis. Acid strength rises H₂O < H₂S < H₂Se < H₂Te, so the conjugate bases weaken O²⁻ > S²⁻ > Se²⁻ > Te²⁻ and pH₁ > pH₂ > pH₃ > pH₄.
Q15AIPMT 2005 Prelims · Q70
Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction ?
Not quite — the answer is C.
With ΔH < 0 (exothermic) and ΔS > 0 (increasing disorder), ΔG = ΔH − TΔS is negative at every temperature. The other combinations are spontaneous only in some temperature range or never.
Q16AIPMT 2005 Prelims · Q71
The vapour pressure of two liquids P and Q are 80 and 60 torr, respectively. The total vapour pressure of solution obtained by mixing 3 moles of P and 2 moles of Q would be :
Not quite — the answer is D.
x_P = 3/5 and x_Q = 2/5. By Raoult's law P = (3/5)(80) + (2/5)(60) = 48 + 24 = 72 torr. 144 torr comes from using mole numbers instead of mole fractions.
Q17AIPMT 2005 Prelims · Q73
For a first order reaction A → B, the reaction rate at reactant concentration of 0.01 M is found to be 2.0 × 10⁻⁵ mol L⁻¹ s⁻¹. The half life period of the reaction is :
Not quite — the answer is D.
For first order, rate = k[A], so k = 2 × 10⁻⁵/0.01 = 2 × 10⁻³ s⁻¹. t½ = 0.693/k = 346.5 ≈ 347 s.
Q18AIPMT 2005 Prelims · Q74
Which of the following is the electron deficient molecule ?
Not quite — the answer is A.
B₂H₆ has only 12 valence electrons, too few for eight normal two-electron bonds, so it uses two three-centre two-electron (B–H–B) bonds and is electron deficient. C₂H₆ and SiH₄ are electron-precise and PH₃ is electron rich (lone pair).
Q19AIPMT 2005 Prelims · Q75
A nuclide of an alkaline earth metal undergoes radioactive decay by emission of three α-particles in succession. The group of the periodic table to which the resulting daughter element would belong is :
Not quite — the answer is A.
Each α-emission lowers Z by 2, so three α-particles lower Z by 6, i.e. six places back in the periodic table. From group 2 this goes to group 14 of the previous period (e.g. Ra, Z = 88 → Pb, Z = 82).
Q20AIPMT 2005 Prelims · Q80
Equilibrium constants K₁ and K₂ for the following equilibria : NO(g) + ½O₂(g) ⇌ NO₂(g) and 2NO₂(g) ⇌ 2NO(g) + O₂(g) are related as :
Not quite — the answer is D.
The second equilibrium is the first reversed and doubled. Reversing gives 1/K₁ and doubling squares it, so K₂ = 1/K₁². 1/K₁ forgets the factor of 2.
Q21AIPMT 2005 Prelims · Q81
Which of the following would have a permanent dipole moment ?
Not quite — the answer is C.
SF₄ has 4 bond pairs and 1 lone pair (see-saw), so its bond dipoles do not cancel. BF₃ (trigonal planar), SiF₄ (tetrahedral) and XeF₄ (square planar) are symmetric with zero net dipole.
Q22AIPMT 2005 Prelims · Q83
The rate of reaction between two reactants A and B decreases by a factor of 4, if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is :
Not quite — the answer is B.
rate ∝ [B]ⁿ. Doubling [B] makes the rate one quarter: 2ⁿ = 1/4, so n = −2. Order +2 would make the rate four times larger.
Q23AIPMT 2005 Prelims · Q86
Which functional group participates in disulphide bond formation in proteins ?
Not quite — the answer is B.
Disulphide bridges (–S–S–) form by oxidation of the thiol (–SH) groups of two cysteine residues. Thioethers (as in methionine) and thioesters do not form disulphide bonds.
Q24AIPMT 2005 Prelims · Q87
Which one of the following is an inner orbital complex as well as diamagnetic in behaviour ? (Atomic no. : Zn = 30, Cr = 24, Co = 27, Ni = 28)
Not quite — the answer is C.
Co³⁺ is 3d⁶; with NH₃ the electrons pair up in t₂g, leaving two 3d orbitals for d²sp³ (inner orbital) hybridisation with no unpaired electrons, so it is diamagnetic. [Cr(NH₃)₆]³⁺ is inner orbital but has 3 unpaired electrons; the Zn²⁺ and Ni²⁺ complexes are outer orbital.
Q25AIPMT 2005 Prelims · Q89
H₂S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because :
Not quite — the answer is A.
HCl suppresses ionisation of H₂S by the common-ion (H⁺) effect, lowering [S²⁻]. This low [S²⁻] still exceeds the very small Ksp of group II sulphides but not the larger Ksp of group IV sulphides. Group II sulphides have smaller, not larger, Ksp.
Q26AIPMT 2005 Prelims · Q90
Which one of the following oxides is expected to exhibit paramagnetic behaviour ?
Not quite — the answer is C.
ClO₂ has an odd number of electrons (33), so it has an unpaired electron and is paramagnetic. CO₂, SO₂ and SiO₂ have all electrons paired.
Q27AIPMT 2005 Prelims · Q91
Which one of the following is expected to exhibit optical isomerism ? (en = ethylenediamine)
Not quite — the answer is D.
cis-[Co(en)₂Cl₂]⁺ has no plane of symmetry and exists as non-superimposable mirror images, so it is optically active. The trans isomer has a mirror plane through the Cl–Co–Cl axis, and square planar [Pt(NH₃)₂Cl₂] isomers are planar and achiral.
Q28AIPMT 2005 Prelims · Q92
The energy of second Bohr orbit of the hydrogen atom is −328 kJ mol⁻¹ ; hence the energy of fourth Bohr orbit would be :
Not quite — the answer is D.
Eₙ ∝ 1/n², so E₄ = E₂ × (2/4)² = −328/4 = −82 kJ mol⁻¹. Dividing by 8 (−41 kJ mol⁻¹) wrongly uses Eₙ ∝ 1/n³.
Q29AIPMT 2005 Prelims · Q93
The correct order of acid strength is :
Not quite — the answer is A.
Acid strength of chlorine oxoacids rises with the oxidation state of Cl (+1 to +7), as more oxygen atoms delocalise the negative charge of the conjugate base: HClO < HClO₂ < HClO₃ < HClO₄. HClO₄ is the strongest, not the weakest.
Q30AIPMT 2005 Prelims · Q94
The main reason for larger number of oxidation states exhibited by the actinides than the corresponding lanthanides, is :
Not quite — the answer is A.
In actinides the 5f, 6d and 7s levels are closer in energy than 4f, 5d and 6s in lanthanides, so more electrons can take part in bonding, giving more oxidation states. A larger energy gap would do the opposite.
Q31AIPMT 2005 Prelims · Q95
Names of some compounds are given. Which one is not correct in IUPAC system ?
Not quite — the answer is D.
For CH₃CH₂CH₂–CH(C₂H₅)–CH(CH₃)–CH₂CH₃ the substituents must be cited alphabetically: 4-ethyl-3-methylheptane, so '3-methyl-4-ethyl heptane' is incorrect. The other three names correctly identify the parent chain and lowest locants.
Q32AIPMT 2005 Prelims · Q96
Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species ?
Not quite — the answer is B.
Cl has the most negative electron gain enthalpy. F and O are less negative than Cl and S because their small size causes strong electron–electron repulsion; also halogens exceed chalcogens. So O < S < F < Cl.
Q33AIPMT 2005 Prelims · Q97
A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be :
Not quite — the answer is D.
x(pentane) = 1/5 = 0.2. p(pentane) = 0.2 × 440 = 88 mm and p(hexane) = 0.8 × 120 = 96 mm, total 184 mm. Vapour mole fraction of pentane = 88/184 ≈ 0.478.
Q34AIPMT 2005 Prelims · Q98
4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from Al³⁺ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H⁺ ions in solution by the same quantity of electric charge will be :
Not quite — the answer is C.
4.5 g Al = 1/6 mol; Al³⁺ needs 3 F per mol, so charge = 0.5 F. 0.5 F liberates 0.25 mol H₂ (2 F per mol H₂) = 0.25 × 22.4 = 5.6 L at STP. 11.2 L forgets that H₂ needs two electrons per molecule.
Q35AIPMT 2005 Prelims · Q100
The mole fraction of the solute in one molal aqueous solution is :
Not quite — the answer is C.
One molal means 1 mol solute in 1000 g water = 55.5 mol water. x(solute) = 1/(1 + 55.5) ≈ 0.0177 ≈ 0.018.
Chemistry: not in the current NEET syllabus
These 4 questions are from topics NCERT dropped in its 2023 revision. Shown for completeness; you can skip them for NEET 2027.
4 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q57
The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is : (Atomic mass Al = 27)
Not quite — the answer is D.
2Al₂O₃ + 3C → 4Al + 3CO₂. 270 kg Al = 10 kmol, needing (3/4) × 10 = 7.5 kmol C = 90 kg. 180 kg assumes CO is formed (1 C per O) instead of CO₂.
Q2AIPMT 2005 Prelims · Q67
The monomer of the polymer : (CH₃)₃C–CH₂–C⁺(CH₃)₂ is :
Not quite — the answer is A.
(CH₃)₃C–CH₂–C⁺(CH₃)₂ is the growing chain in cationic polymerisation of isobutylene: each step adds a CH₂=C(CH₃)₂ unit. So the monomer is H₂C=C(CH₃)₂. Tetramethylethylene or propene cannot produce this repeating pattern.
Q3AIPMT 2005 Prelims · Q76
The surface tension of which of the following liquid is maximum ?
Not quite — the answer is A.
Water has extensive three-dimensional hydrogen bonding, giving it the strongest intermolecular forces and hence the highest surface tension (≈ 72 mN m⁻¹). Methanol and ethanol hydrogen bond less extensively and benzene not at all.
Q4AIPMT 2005 Prelims · Q78
Which one of the following forms micelles in aqueous solution above certain concentration ?
Not quite — the answer is B.
Dodecyl trimethyl ammonium chloride is a cationic surfactant with a long hydrophobic tail and an ionic head, so above the critical micelle concentration it forms micelles. Urea, glucose and pyridinium chloride lack a long hydrophobic chain.
Chapter-wise split of AIPMT 2005 Prelims Chemistry
- Chemical Bonding and Molecular Structure5 Q
- Organic Chemistry: Some Basic Principles and Techniques3 Q
- The d- and f-Block Elements3 Q
- Equilibrium3 Q
- Solutions3 Q
- Thermodynamics2 Q
- Chemical Kinetics2 Q
- Classification of Elements and Periodicity in Properties2 Q
- Coordination Compounds2 Q
- Hydrocarbons1 Q
- Amines1 Q
- Aldehydes, Ketones and Carboxylic Acids1 Q
- Redox Reactions1 Q
- Alcohols, Phenols and Ethers1 Q
- Biomolecules1 Q
- Structure of Atom1 Q
- Electrochemistry1 Q
AIPMT 2005 Prelims Biology questions
72 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q101
The main organelle involved in modification and routing of newly synthesized proteins to their destinations is :
Not quite — the answer is B.
Proteins made on ribosomes attached to the rough endoplasmic reticulum enter its lumen, where they are folded, glycosylated and packed into vesicles for transport onward (via the Golgi) to their destinations. Mitochondria and chloroplasts make ATP and food, and lysosomes digest material; none of them sort and route new proteins.
Q2AIPMT 2005 Prelims · Q102
There are two opposing views about origin of Modern man. According to one view Homo erectus in Asia were the ancestors of modern man. A study of variations of DNA however suggested African origin of Modern man. What kind of observation on DNA variation could suggest this ?
Not quite — the answer is A.
Mutations pile up over time, so the oldest human population carries the most genetic diversity. Greater DNA (mitochondrial) variation in African populations than in Asian ones shows that humans lived longest in Africa, which points to an African origin. Greater variation in Asia would instead support an Asian origin.
Q3AIPMT 2005 Prelims · Q106
At what stage of the cell cycle are histone proteins synthesized in a eukaryotic cell ?
Not quite — the answer is C.
Histones are made in the S phase, at the same time as DNA replication, so the newly copied DNA can be packed into nucleosomes straight away. Prophase and telophase are stages of mitosis, and G2 is not part of prophase.
Q4AIPMT 2005 Prelims · Q107
There exists a close association between the alga and the fungus within a lichen. The fungus :
Not quite — the answer is B.
In a lichen, the algal partner (phycobiont) photosynthesises and makes food. The fungal partner (mycobiont) gives shelter, anchorage, and absorbs water and minerals for it. Food and oxygen come from the alga, not the fungus.
Q5AIPMT 2005 Prelims · Q108
For retting of jute the fermenting microbe used is :
Not quite — the answer is D.
During retting, jute stems are soaked in water and anaerobic butyric acid bacteria (such as Clostridium) break down the pectin that holds the fibres together, which frees the fibres. Helicobacter pylori causes stomach ulcers and lactic streptococci sour milk; neither one rets fibres.
Q6AIPMT 2005 Prelims · Q109
A student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution ?
Not quite — the answer is C.
Resolving power improves as the wavelength gets shorter (the resolution limit is about 0.61λ/NA). Blue has the shortest wavelength of the colours listed, so it gives the finest resolution. Red has the longest wavelength and gives the poorest.
Q7AIPMT 2005 Prelims · Q112
A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters are affected. Which of the following mode of inheritance do you suggest for this disease ?
Not quite — the answer is D.
Unaffected parents with affected sons only fits an X-linked recessive trait: the mother is a carrier and passes the mutant X to some sons, while daughters receive the father's normal X and are not affected. A dominant trait would show up in at least one of the parents.
Q8AIPMT 2005 Prelims · Q113
In Ornithine cycle, which of the following wastes are removed from the blood ?
Not quite — the answer is C.
In the liver's ornithine (urea) cycle, toxic ammonia and carbon dioxide taken from the blood are combined into urea. So the wastes removed from the blood are CO₂ and ammonia, and urea is the product that is formed, not removed.
Q9AIPMT 2005 Prelims · Q114
Telomerase is an enzyme which is a :
Not quite — the answer is D.
Telomerase has a protein reverse-transcriptase part plus its own RNA, which serves as the template for adding telomere repeats. That makes it a ribonucleoprotein, not a simple protein and not RNA alone.
Q10AIPMT 2005 Prelims · Q115
During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is that sequence called ?
Not quite — the answer is D.
The promoter's TATA box (Pribnow box in prokaryotes) is the AT-rich site where RNA polymerase binds. The DNA bends and opens easily there to start transcription. The CAAT box lies further upstream and mainly regulates how often transcription starts.
Q11AIPMT 2005 Prelims · Q116
Centromere is required for :
Not quite — the answer is D.
The centromere carries the kinetochores, where spindle fibres attach. This lets chromatids or chromosomes be pulled towards the poles during anaphase. It has no role in transcription or cytokinesis.
Q12AIPMT 2005 Prelims · Q117
Damage to thymus in a child may lead to :
Not quite — the answer is D.
T lymphocytes mature in the thymus, and T cells drive cell-mediated immunity. Damage to the thymus in childhood therefore causes loss of cell-mediated immunity. Antibody-mediated immunity relies mainly on B cells, which mature in the bone marrow.
Q13AIPMT 2005 Prelims · Q119
Chlorophyll in chloroplasts is located in :
Not quite — the answer is A.
Chlorophyll sits in the thylakoid membranes, which are stacked into grana. The stroma is the fluid matrix where the dark reactions happen and holds no pigment, and the pyrenoid is a starch-forming body in algae.
Q14AIPMT 2005 Prelims · Q122
Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain ?
Not quite — the answer is C.
Endonucleases cut phosphodiester bonds within a DNA or RNA chain; restriction enzymes are an example. Exonucleases remove nucleotides only from the ends. Lipases and proteases act on fats and proteins.
Q15AIPMT 2005 Prelims · Q123
Match items in column-I with those in column-II. Column-I: (a) Peritrichous flagellation; (b) Living fossil; (c) Rhizophore; (d) Smallest flowering plant; (e) Largest perennial alga Column-II: 1. Ginkgo; 2. Macrocystes; 3. Escherichia coli; 4. Selaginella; 5. Wolffia Select the correct answer from the following : Codes :
Not quite — the answer is D.
E. coli has flagella all over its surface (peritrichous). Ginkgo is a living fossil. Selaginella has leafless rhizophores that bear roots. Wolffia is the smallest flowering plant, and the kelp Macrocystis is the largest perennial alga. That gives (a)-3, (b)-1, (c)-4, (d)-5, (e)-2.
Q16AIPMT 2005 Prelims · Q125
G-6-P dehydrogenase deficiency is associated with haemolysis of :
Not quite — the answer is B.
Red blood cells rely on glucose-6-phosphate dehydrogenase to make NADPH, which protects them from oxidative damage. In the X-linked deficiency, oxidant drugs or fava beans cause RBCs to break down (haemolytic anaemia). White cells and platelets are not the cells that lyse.
Q17AIPMT 2005 Prelims · Q127
According to IUCN red list what is the status of red Panda (Ailurus fulgens) ?
Not quite — the answer is D.
The red panda of the eastern Himalayas is listed as Endangered by the IUCN because of habitat loss and poaching. It is not extinct and has not been placed in the critically endangered category.
Q18AIPMT 2005 Prelims · Q128
Which of the following substances, if introduce in the blood stream, would cause coagulation, at the site of its introduction ?
Not quite — the answer is D.
Thromboplastin (tissue factor) starts the clotting cascade, which leads to thrombin formation and turns fibrinogen into fibrin, so a clot forms where it is introduced. Fibrinogen and prothrombin already circulate in plasma without clotting, and heparin is an anticoagulant.
Q19AIPMT 2005 Prelims · Q129
E. coli cells with a mutated Z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because :
Not quite — the answer is D.
The z gene codes for β-galactosidase, which splits lactose into glucose and galactose. Without a working enzyme, lactose cannot be used for energy. Lactose transport depends on permease, the y gene product, so the transport option describes a y mutation instead.
Q20AIPMT 2005 Prelims · Q130
Top-shaped multiciliate male gametes and the mature seed which bears only one embryo with two cotyledons, are characteristic features of :
Not quite — the answer is D.
Cycads have large, top-shaped male gametes with many cilia, which is a primitive trait. Their seed carries one embryo with two cotyledons. Angiosperms and conifers have non-motile male gametes delivered by a pollen tube.
Q21AIPMT 2005 Prelims · Q131
Production of a human protein in bacteria by genetic engineering is possible because :
Not quite — the answer is D.
Because the genetic code is universal, bacterial ribosomes read a human gene's codons as the same amino acids and so make the human protein. Bacteria cannot splice introns (cDNA is used for that reason), and gene regulation differs between bacteria and humans.
Q22AIPMT 2005 Prelims · Q132
From the following statements select the wrong one :
Not quite — the answer is C.
NCERT describes sponges as 'generally marine', and freshwater sponges such as Spongilla exist, so 'exclusively marine' is the wrong statement. Millipedes have two pairs of legs on each (diplo)segment, prawns carry antennules plus antennae (two pairs), and nematocysts are unique to cnidarians.
Q23AIPMT 2005 Prelims · Q133
Nucleotide are building blocks of nucleic acids, nucleotide is a composite molecule formed by :
Not quite — the answer is C.
A nucleotide is a nitrogenous base joined to a pentose sugar (a nucleoside) plus a phosphate group. '(base-sugar-phosphate)n' describes a polynucleotide chain, and 'base-sugar' alone is a nucleoside.
Q24AIPMT 2005 Prelims · Q136
Which one of the following characters is not typical of the class-mammalia ?
Not quite — the answer is C.
Mammals have twelve pairs of cranial nerves; ten pairs is the condition in fishes and amphibians. Seven neck vertebrae, teeth set in sockets (thecodont) and alveolar lungs are all typical mammalian traits.
Q25AIPMT 2005 Prelims · Q137
Which of the following is the simplest amino acid ?
Not quite — the answer is C.
Glycine is the simplest amino acid because its R group is just a hydrogen atom. Alanine has a methyl group, and tyrosine and asparagine have larger side chains.
Q26AIPMT 2005 Prelims · Q138
Barophilic prokaryotes :
Not quite — the answer is C.
'Baro' means pressure. Barophilic (piezophilic) prokaryotes thrive under the very high hydrostatic pressure of deep-sea sediments. The term has nothing to do with barium salts.
Q27AIPMT 2005 Prelims · Q139
Auxospores and hormocysts are formed, respectively, by :
Not quite — the answer is A.
Auxospores are formed by many diatoms to restore full cell size after repeated divisions shrink the silica frustule. Hormocysts are thick-walled, multicellular perennating filaments made by only a few filamentous cyanobacteria (such as Westiella). So the order is diatoms first, then cyanobacteria, and hormocysts are restricted to a few.
Q28AIPMT 2005 Prelims · Q140
Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these :
Not quite — the answer is D.
What enzymes, vitamins (often as coenzymes) and hormones have in common is that they control the rate and direction of metabolism. They are not all proteins (many vitamins and steroid hormones are not), and vitamins are mostly obtained from food rather than made in the body.
Q29AIPMT 2005 Prelims · Q141
Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution ?
Not quite — the answer is C.
When a pesticide is used, the rare resistant insects survive and reproduce, so resistance spreads through the population. This is natural selection working on existing variation. Transgenics, cloning and stem-cell organs are human technologies, not natural selection.
Q30AIPMT 2005 Prelims · Q142
As compared to a C₃ plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C₄ plants :
Not quite — the answer is D.
A C₃ plant needs 18 ATP per hexose. A C₄ plant also spends 2 ATP per CO₂ to regenerate PEP (pyruvate to PEP), which is 12 more for six CO₂, giving 30 ATP in total. So it needs 12 extra ATP.
Q31AIPMT 2005 Prelims · Q143
In a man, abducens nerve is injured. Which one of the following functions will be affected ?
Not quite — the answer is A.
The abducens (VI cranial) nerve supplies the lateral rectus muscle, which turns the eyeball outward, so eye movement is affected. The tongue is moved by the hypoglossal nerve, swallowing involves the glossopharyngeal and vagus nerves, and the neck by the accessory nerve.
Q32AIPMT 2005 Prelims · Q145
Protein synthesis in an animal cell occurs :
Not quite — the answer is B.
Animal cells translate proteins on cytoplasmic 80S ribosomes (both free and ER-bound) and also on the 70S ribosomes inside mitochondria, which have their own DNA. The nucleolus assembles ribosomal subunits but does not make proteins.
Q33AIPMT 2005 Prelims · Q146
Which of the following is not true for a species ?
Not quite — the answer is D.
Populations of one species can interbreed, so gene flow does take place between them, and the statement that it does not is false. Interbreeding, variation within the species and reproductive isolation from other species are all true of a biological species.
Q34AIPMT 2005 Prelims · Q147
One of the most important functions of botanical gardens is that :
Not quite — the answer is B.
Botanical gardens keep living plant collections away from their natural habitats, which makes them a key means of ex situ conservation of germplasm. Providing natural habitat for wildlife is in situ conservation (national parks, sanctuaries).
Q35AIPMT 2005 Prelims · Q149
Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example :
Not quite — the answer is C.
Poison fangs are mainly used by snakes to kill prey (offence), not to escape predators. Puffing up (puffer fish), dark camouflage (melanic moths) and colour change (chameleon) all help avoid predation.
Q36AIPMT 2005 Prelims · Q150
At a particular locus, frequency of 'A' allele is 0.6 and that of 'a' is 0.4. What would be the frequency of heterozygotes in a random mating population at equilibrium ?
Not quite — the answer is B.
By the Hardy-Weinberg principle, the heterozygote frequency is 2pq = 2 × 0.6 × 0.4 = 0.48. 0.36 (p²) and 0.16 (q²) are the frequencies of the two homozygotes.
Q37AIPMT 2005 Prelims · Q151
Which one of the following experiments suggests that simplest living organisms could not have originated spontaneously from non-living matter ?
Not quite — the answer is D.
When the material was heated (sterilised) and sealed off from outside microbes, it did not spoil. This shows that life comes from pre-existing life (Spallanzani/Pasteur-type experiments). Microbes appearing in unsterilised material is exactly what spontaneous generation was wrongly claimed to explain.
Q38AIPMT 2005 Prelims · Q152
Biodiversity act of India was passed by the Parliament in the year :
Not quite — the answer is C.
India's Biological Diversity Act was passed in 2002, after the 1992 Convention on Biological Diversity (Rio Earth Summit). 1992 is the year of the convention, not of the Indian Act.
Q39AIPMT 2005 Prelims · Q153
During which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP ?
Not quite — the answer is B.
Most of the ATP from aerobic respiration (about 34 of 38 in the older count) is made by oxidative phosphorylation as NADH and FADH₂ pass electrons down the electron transport chain. Glycolysis and the Krebs cycle make only a few ATP directly, by substrate-level phosphorylation.
Q40AIPMT 2005 Prelims · Q154
A woman with normal vision, but whose father was colour blind, marries a colourblind man. Suppose that the fourth child of this couple was a boy. This boy :
Not quite — the answer is D.
The woman got her colour-blind father's X, so she is a carrier (XᶜX). A son always gets his X from his mother, so each son has a 50% chance of colour blindness, whatever the birth order. Males carry only one X, so a son cannot be heterozygous.
Q41AIPMT 2005 Prelims · Q155
Ectophloic siphonostele is found in :
Not quite — the answer is B.
An ectophloic siphonostele has a pith with phloem only outside the xylem ring; it is found in Osmunda and Equisetum. Adiantum (maidenhair fern), Marsilea and Dicksonia have amphiphloic stelar types, with phloem on both sides of the xylem.
Q42AIPMT 2005 Prelims · Q156
Which of the following represents the edible part of the fruit of litchi ?
Not quite — the answer is C.
The juicy white flesh of litchi is an aril, a fleshy outgrowth of the seed, not part of the fruit wall. The pericarp is the inedible rough outer rind.
Q43AIPMT 2005 Prelims · Q157
Carbohydrates, the most abundant biomolecules on earth, are produced by :
Not quite — the answer is C.
Carbohydrates are made by photosynthetic (and chemosynthetic) autotrophs: some bacteria, algae and green plants. Fungi and viruses cannot make carbohydrate from CO₂, and not all bacteria are autotrophic.
Q44AIPMT 2005 Prelims · Q159
Which of the following is not a hereditary disease ?
Not quite — the answer is A.
Cretinism is caused by thyroid hormone deficiency in childhood (often iodine deficiency), a hormonal disorder rather than an inherited gene defect. Cystic fibrosis, thalassaemia and haemophilia are all Mendelian genetic disorders.
Q45AIPMT 2005 Prelims · Q161
de Vries gave his mutation theory on organic evolution while working on :
Not quite — the answer is C.
Hugo de Vries based his mutation theory on sudden large variations he saw in the evening primrose, Oenothera lamarckiana. Drosophila was Morgan's organism and Pisum sativum was Mendel's.
Q46AIPMT 2005 Prelims · Q164
Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on :
Not quite — the answer is A.
Mitchell's chemiosmotic theory says that electron transport pumps protons across a membrane, and the protons flowing back through ATP synthase (CF₀-CF₁ or F₀-F₁) drive ATP formation. The driving force is the proton gradient, not K⁺ or Na⁺ build-up.
Q47AIPMT 2005 Prelims · Q165
Parkinson's disease (characterized by tremors and progressive rigidity of limbs) is caused by degeneration of brain neurons that are involved in movement control and make use of neurotransmitter :
Not quite — the answer is C.
Parkinson's disease results from the loss of dopamine-producing neurons in the substantia nigra, which regulate movement through the basal ganglia. Treatment therefore replaces dopamine (L-DOPA). Loss of acetylcholine neurons is linked mainly to Alzheimer's disease.
Q48AIPMT 2005 Prelims · Q167
An acromian process is characteristically found in the :
Not quite — the answer is C.
The acromion is the flat projection at the end of the scapular spine, so it belongs to the pectoral girdle of mammals. Do not confuse it with the acrosome of a sperm.
Q49AIPMT 2005 Prelims · Q168
In a type of apomixis known as adventive embryony, embryos develop directly from the :
Not quite — the answer is A.
In adventive embryony (seen in Citrus and mango), diploid nucellar or integument cells outside the embryo sac grow directly into embryos, with no gametophyte step. Embryos formed from synergids or antipodals are a different kind of apomixis, and an embryo from a zygote is normal sexual reproduction.
Q50AIPMT 2005 Prelims · Q169
Through which cell of the embryo sac, does the pollen tube enter the embryo sac ?
Not quite — the answer is D.
The pollen tube, guided by the filiform apparatus, enters one of the synergids, which degenerates and releases the male gametes. The other, persistent synergid is not entered, and the tube does not go directly into the egg or the central cell.
Q51AIPMT 2005 Prelims · Q172
Which one of the following pairs is mismatched ?
Not quite — the answer is B.
Prairies are temperate grasslands with few trees, so epiphytes (plants growing on other plants, typical of tropical rain forests) do not fit there. Acacia in savanna, permafrost in tundra and evergreen conifers in coniferous forest are all correct pairs.
Q52AIPMT 2005 Prelims · Q174
Which one of the following represents an ovule, where the embryo sac becomes horse-shoe shaped and the funiculus and micropyle are close to each other ?
Not quite — the answer is C.
In an amphitropous ovule, both the body of the ovule and the embryo sac are curved into a horseshoe shape, which brings the micropyle close to the funiculus. An anatropous ovule is inverted but its embryo sac stays straight, and an atropous ovule is upright.
Q53AIPMT 2005 Prelims · Q177
Which one of the following makes use of RNA as a template to synthesize DNA ?
Not quite — the answer is A.
Reverse transcriptase, found in retroviruses such as HIV, is an RNA-dependent DNA polymerase that copies RNA into DNA. DNA polymerase copies DNA into DNA, and RNA polymerase copies DNA into RNA.
Q54AIPMT 2005 Prelims · Q178
In contrast to annelids the platyhelminths show :
Not quite — the answer is D.
Flatworms are acoelomates with no body cavity, whereas annelids are true coelomates. Both groups are bilaterally symmetrical, so bilateral symmetry does not set them apart, and a pseudocoel is found in roundworms.
Q55AIPMT 2005 Prelims · Q179
Which of the following statements regarding enzyme inhibition is correct ?
Not quite — the answer is C.
In competitive inhibition, a substrate-like inhibitor competes with the substrate for the enzyme's active site (for example malonate against succinate). Adding more substrate overcomes competitive inhibition, not non-competitive inhibition.
Q56AIPMT 2005 Prelims · Q180
Which of the following pairs is correctly matched ?
Not quite — the answer is D.
The articular processes (zygapophyses) of adjacent vertebrae meet at gliding joints. Skull bones are joined by fibrous sutures, the bodies of vertebrae by cartilaginous joints, and phalanges by hinge joints.
Q57AIPMT 2005 Prelims · Q181
The catalytic efficiency of two different enzymes can be compared by the :
Not quite — the answer is A.
Km, the substrate concentration that gives half the maximum velocity, reflects an enzyme's affinity for its substrate: a lower Km means higher affinity and efficiency. It is the standard value for comparing enzymes. pH optimum and molecular size say nothing about catalytic efficiency.
Q58AIPMT 2005 Prelims · Q184
Haemophilia is more commonly seen in human males than in human females because :
Not quite — the answer is C.
Haemophilia is X-linked recessive. Males have one X, so one mutant allele causes the disease, while females need two copies and are usually carriers. A Y-linked trait would never appear in females at all.
Q59AIPMT 2005 Prelims · Q185
A woman with 47 chromosomes due to three copies of chromosome 21 is characterized by :
Not quite — the answer is A.
Trisomy 21 (47 chromosomes) is Down syndrome. Turner syndrome is 45,XO, super female is XXX (trisomy of the X), and triploidy would mean three full sets (69 chromosomes).
Q60AIPMT 2005 Prelims · Q186
In order to find out the different types of gametes produced by a pea plant having the genotype AaBb, it should be crossed to a plant with the genotype
Not quite — the answer is D.
A test cross with the double recessive aabb works because that parent gives only ab gametes, so each offspring's phenotype shows exactly which gamete came from the AaBb plant. Dominant alleles in the tester would hide the recessive gametes.
Q61AIPMT 2005 Prelims · Q187
Four healthy people in their twenties got involved in injuries resulting in damage and death of a few cells of the following. Which of the cells are least likely to be replaced by new cells ?
Not quite — the answer is D.
Mature neurons are permanently out of the cell cycle (G₀) and are generally not replaced. The Malpighian layer of the skin divides all the time, liver cells can regenerate, and bone is remodelled by osteoblasts.
Q62AIPMT 2005 Prelims · Q188
Secretin and cholecystokinin are digestive hormones. They are secreted in :
Not quite — the answer is C.
When acidic chyme and fat enter the duodenum, its mucosa releases secretin and CCK, which act on the pancreas, liver and gall bladder. The pyloric stomach releases gastrin, not these hormones.
Q63AIPMT 2005 Prelims · Q189
Which of the following unicellular organism has a macro-nucleus for trophic function and one or more micro-nuclei for reproduction ?
Not quite — the answer is C.
Ciliates such as Paramecium have nuclear dimorphism: a large macronucleus controls everyday metabolism, and micronuclei take part in conjugation. Euglena, Amoeba and Trypanosoma each have a single kind of nucleus.
Q64AIPMT 2005 Prelims · Q190
AIDS is caused by HIV that principally infects :
Not quite — the answer is C.
HIV attaches to the CD4 receptor, so it mainly infects helper T (T4) lymphocytes (and macrophages). The steady fall in these cells causes immunodeficiency. Cytotoxic T cells are CD8 and are not the main target.
Q65AIPMT 2005 Prelims · Q191
According to widely accepted "fluid mosaic model" cell membranes are semi-fluid, where lipids and integral proteins can diffuse randomly. In recent years, this model has been modified in several respects. In this regard, which of the following statements is incorrect?
Not quite — the answer is C.
Membrane proteins can move sideways within the bilayer but practically never flip from one face to the other. Their hydrophilic parts cannot cross the hydrophobic core, and this is why membranes stay asymmetric. Lipids can flip-flop slowly; proteins do not.
Q66AIPMT 2005 Prelims · Q193
A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of :
Not quite — the answer is B.
During prolonged fasting, the body burns stored fat. Incomplete oxidation of fatty acids produces ketone bodies, which spill into the urine (ketonuria). Glucose in the urine indicates diabetes, not starvation.
Q67AIPMT 2005 Prelims · Q194
Why is vivipary an undesirable character for annual crop plants ?
Not quite — the answer is B.
In vivipary, seeds germinate while still on the parent plant without any dormancy, so they cannot be dried and stored for sowing next season. That makes the trait undesirable for annual crops. Vivipary means no dormancy, the opposite of long dormancy.
Q68AIPMT 2005 Prelims · Q195
Bacillus thuringiensis (Bt) strains have been used for designing novel :
Not quite — the answer is C.
Bt makes Cry protein toxins that kill specific insect larvae. Transferring cry genes into crops (Bt cotton, Bt brinjal) produces insect-resistant transgenic plants. Bt is not a biofertiliser and plays no part in metal extraction.
Q69AIPMT 2005 Prelims · Q196
The salivary gland chromosomes in the dipteran larvae, are useful in gene mapping because :
Not quite — the answer is D.
Polytene chromosomes form by repeated DNA replication without cell division (endoreduplication), so many chromatids lie side by side. This gives clear band patterns that can be linked to particular genes. Their large size is a result of endoreduplication, and the bands are what make mapping possible.
Q70AIPMT 2005 Prelims · Q198
Photosynthetic Active Radiation (PAR) has the following range of wavelengths :
Not quite — the answer is A.
NCERT gives PAR as light from 400 to 700 nm, the visible band that chlorophylls and carotenoids absorb. Wavelengths beyond 700 nm (far-red, infrared) and in the ultraviolet are not used for photosynthesis.
Q71AIPMT 2005 Prelims · Q199
Golden rice is a transgenic crop of the future with the following improved trait :
Not quite — the answer is D.
Golden rice is engineered to make β-carotene (provitamin A) in its grain, which gives it a golden colour and helps fight vitamin A deficiency. Insect resistance is the trait of Bt crops, and high lysine is the trait of quality-protein maize.
Q72AIPMT 2005 Prelims · Q200
Which one of the following depresses brain activity and produces feelings of calmness, relaxation and drowsiness.
Not quite — the answer is A.
Valium (diazepam), a benzodiazepine tranquilliser, depresses the central nervous system and brings calm, relaxation and drowsiness. Amphetamines are stimulants, hashish is a cannabinoid that alters perception, and morphine is an opioid painkiller.
Biology: not in the current NEET syllabus
These 19 questions are from topics NCERT dropped in its 2023 revision. Shown for completeness; you can skip them for NEET 2027.
19 questions. Tap an option to check your answer.
Q1AIPMT 2005 Prelims · Q103
The world's highly prized wool yielding 'Pashmina' breed is :
Not quite — the answer is B.
Pashmina is the fine under-fleece of the Changthangi goat of the cold Ladakh/Kashmir plateau. It is not sheep wool, and it does not come from a cross-breed.
Q2AIPMT 2005 Prelims · Q104
Grey crescent is the area :
Not quite — the answer is B.
In a frog egg, sperm entry makes the pigmented cortex rotate, which exposes a lighter grey band on the side opposite the entry point. This grey crescent later marks the dorsal side of the embryo (dorsal lip of the blastopore). It is not at the entry site itself or at either pole.
Q3AIPMT 2005 Prelims · Q111
At which latitude, heat gain through insolation approximately equals heat loss through terrestrial radiation ?
Not quite — the answer is C.
Between the equator and about 40° latitude, incoming solar energy is more than outgoing radiation (a surplus). Poleward of about 40°, outgoing radiation is greater (a deficit). The two balance near 40° N and S. 66° marks the polar circles and 22½° is near the tropics; neither is the balance line.
Q4AIPMT 2005 Prelims · Q118
Prolonged liberal irrigation of agricultural fields is likely to create the problem of :
Not quite — the answer is D.
Heavy irrigation, especially with poor drainage, raises the water table. Evaporation then leaves dissolved salts on the surface, which makes the soil saline. Irrigation does not cause aridity, and it does not usually cause acidity.
Q5AIPMT 2005 Prelims · Q120
Three crops that contribute maximum to global food grain production are :
Not quite — the answer is A.
Wheat, rice and maize are the world's three main cereals and together supply most of the global food grain. Sorghum and barley are much smaller contributors.
Q6AIPMT 2005 Prelims · Q121
Genes for cytoplasmic male sterility in plants are generally located in :
Not quite — the answer is A.
Cytoplasmic male sterility is inherited through the mother and is caused by rearranged genes in the mitochondrial genome, which disrupt pollen development. Nuclear restorer genes can override it, but the sterility genes themselves are mitochondrial, not chloroplast or nuclear.
Q7AIPMT 2005 Prelims · Q124
The name of Norman Borlaug is associated with :
Not quite — the answer is A.
Norman Borlaug bred high-yielding, semi-dwarf, disease-resistant wheat varieties that drove the Green Revolution and won him the 1970 Nobel Peace Prize. The White Revolution (milk) is linked to Verghese Kurien.
Q8AIPMT 2005 Prelims · Q126
In which one pair both the plants can be vegetatively propagated by leaf pieces ?
Not quite — the answer is A.
Bryophyllum and Kalanchoe (closely related succulents) grow adventitious buds from notches on the leaf margin, so a leaf piece can give rise to new plants. Agave reproduces by bulbils, Chrysanthemum by suckers and Asparagus by its root system, not by leaves.
Q9AIPMT 2005 Prelims · Q135
Which one of the following pairs is mismatched ?
Not quite — the answer is D.
Solar energy is a clean source that releases no greenhouse gases, so linking it to the greenhouse effect is a mismatch. Burning biomass or fossil fuel releases CO₂, and nuclear power produces radioactive waste.
Q10AIPMT 2005 Prelims · Q144
An important step in the manufacture of pulp for paper industry from the woody tissues of plants is the :
Not quite — the answer is A.
Paper is made from cellulose fibres, so pulping removes lignin chemically (for example by the sulphate or sulphite process) and leaves relatively pure cellulose. Breaking down the cellulose would destroy the very fibres that make up paper.
Q11AIPMT 2005 Prelims · Q148
The ability of the venus flytrap to capture insects is due to :
Not quite — the answer is D.
When an insect touches the trigger hairs, the cells of the leaf lobes rapidly lose or gain turgor (and expand quickly), so the trap snaps shut. Plants have no muscle cells, and the closure is an active response to touch, not to a chemical.
Q12AIPMT 2005 Prelims · Q158
Identify the correctly matched pair :
Not quite — the answer is B.
The Kyoto Protocol (1997) set limits on greenhouse gas emissions to tackle climate change. The Montreal Protocol is about ozone-depleting substances, Ramsar about wetlands, and Basel about cross-border movement of hazardous waste.
Q13AIPMT 2005 Prelims · Q160
The deficiencies of micro-nutrients, not only affects growth of plants but also vital functions such as photosynthetic and mitochondrial electron flow. Among the list given below, which group of three elements shall affect most, both photosynthetic and mitochondrial electron transport ?
Not quite — the answer is A.
Iron (in cytochromes and Fe-S proteins), copper (in plastocyanin and cytochrome oxidase) and manganese (in water splitting at PSII) are directly involved in electron carriers. Co, Ni and Mo are needed in nitrogen-related enzymes, and Ca and Na are not electron carriers.
Q14AIPMT 2005 Prelims · Q163
Which of the following is not used for disinfection of drinking water ?
Not quite — the answer is A.
Phenyl (a phenolic disinfectant) is toxic and is used only on floors and drains, never in drinking water. Chlorine, chloramine and ozone are standard disinfectants for drinking water.
Q15AIPMT 2005 Prelims · Q170
Epithelial cells of the intestine involved in food absorption have on their surface :
Not quite — the answer is D.
Absorptive intestinal cells have a brush border of microvilli that greatly increases the surface area for absorption. Zymogen granules store enzymes in secretory cells and are not surface structures.
Q16AIPMT 2005 Prelims · Q171
A patient is generally advised to specially, consume more meat, lentils, milk and eggs in diet only when he suffers from :
Not quite — the answer is A.
Meat, lentils, milk and eggs are rich in protein, and kwashiorkor is caused by protein deficiency. Rickets needs vitamin D and calcium, scurvy needs vitamin C, and anaemia is treated mainly with iron.
Q17AIPMT 2005 Prelims · Q175
Potometer works on the principle of :
Not quite — the answer is A.
A potometer measures how fast a cut shoot takes up water and assumes this equals the water lost by transpiration. It does not measure osmotic pressure or root pressure.
Q18AIPMT 2005 Prelims · Q183
Which of the following is generally used for induced mutagenesis in crop plants ?
Not quite — the answer is D.
Gamma rays from a cobalt-60 source penetrate seeds and tissues well and are the most common mutagen in plant mutation breeding. Alpha particles penetrate too little, and UV acts only on surface cells or pollen.
Q19AIPMT 2005 Prelims · Q197
Which group of three of the following five statements (1-5) contain is all three correct statements regarding beri-beri ? A. A crippling disease prevalent among the native population of sub-Sahara Africa. B. A deficiency disease caused by lack of thiamine (vitamin B1). C. A nutritional disorder in infants and young children when the diet is persistently deficient in essential protein. D. Occurs in those countries where the staple diet is polished rice. E. The symptoms are pain from neuritis, paralysis, muscle wasting, progressive oedema, mental deterioration and finally heart failure.
Not quite — the answer is D.
Beri-beri is caused by lack of thiamine (vitamin B1). It is common where polished rice, with its thiamine-rich husk removed, is the staple food, and it causes neuritis, paralysis, oedema and heart failure. Statement C describes kwashiorkor, a protein deficiency, not beri-beri.
Chapter-wise split of AIPMT 2005 Prelims Biology
- Principles of Inheritance and Variation8 Q
- Evolution6 Q
- Photosynthesis in Higher Plants5 Q
- Biomolecules5 Q
- Cell: The Unit of Life4 Q
- Biological Classification4 Q
- Molecular Basis of Inheritance4 Q
- Sexual Reproduction in Flowering Plants4 Q
- Human Health and Disease3 Q
- Plant Kingdom3 Q
- Biodiversity and Conservation3 Q
- Animal Kingdom3 Q
- Neural Control and Coordination3 Q
- Cell Cycle and Cell Division2 Q
- Excretory Products and Their Elimination2 Q
- Biotechnology: Principles and Processes2 Q
- Organisms and Populations2 Q
- Locomotion and Movement2 Q
- Biotechnology and Its Applications2 Q
- Microbes in Human Welfare1 Q
- Body Fluids and Circulation1 Q
- Respiration in Plants1 Q
- Morphology of Flowering Plants1 Q
- Chemical Coordination and Integration1 Q
About this paper
How many questions from AIPMT 2005 Prelims are on this page?
170 questions (Physics 40, Chemistry 39, Biology 91). Questions that need a diagram we could not reproduce, or whose wording in the source was unclear, are left out.
Are these the original questions?
Yes. The questions and options are as set in the AIPMT 2005 Prelims paper, conducted by CBSE. The answer to every question was checked by the RankUp team, and the explanations are RankUp's own.
Is AIPMT 2005 Prelims useful for NEET 2027?
Yes. The NEET syllabus is built on the same NCERT books. 28 questions here are on topics NCERT has since dropped; they are listed separately so you can skip them.
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