NEET 2018 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
162 questions from the NEET 2018 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.
- Exam
- NEET 2018
- Conducted by
- CBSE
- Physics
- 36 questions
- Chemistry
- 40 questions
- Biology
- 86 questions
NEET 2018 Physics questions
36 questions. Tap an option to check your answer.
Q1NEET 2018 · Q3
At what temperature will the rms speed of oxygen molecules become just sufficient for escaping from the Earth's atmosphere? (Given: Mass of oxygen molecule (m) = 2.76 × 10⁻²⁶ kg, Boltzmann's constant k_B = 1.38 × 10⁻²³ J K⁻¹)
Not quite — the answer is B.
Set v_rms = √(3k_BT/m) equal to the escape speed 11.2 km/s. T = mv²/(3k_B) = 2.76 × 10⁻²⁶ × (1.12 × 10⁴)² / (3 × 1.38 × 10⁻²³) ≈ 8.36 × 10⁴ K. Using 2k_BT or k_BT instead of 3k_BT gives the other values.
Q2NEET 2018 · Q4
The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is
Not quite — the answer is C.
Carnot efficiency η = 1 − T₂/T₁ = 1 − 273/373 = 100/373 ≈ 26.8%. Temperatures must be in kelvin; using Celsius would wrongly give 100%.
Q3NEET 2018 · Q5
A carbon resistor of (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be
Not quite — the answer is B.
47 kΩ = 47 × 10³ Ω: first digit 4 is yellow, second digit 7 is violet, multiplier 10³ is orange. The tolerance 4.7/47 = 10% is silver (gold would be 5%).
Q4NEET 2018 · Q6
A set of 'n' equal resistors, of value 'R' each, are connected in series to a battery of emf 'E' and internal resistance 'R'. The current drawn is I. Now, the 'n' resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of 'n' is
Not quite — the answer is C.
Series: I = E/(nR + R). Parallel: 10I = E/(R/n + R) = nE/((n + 1)R). Dividing, 10 = n(n + 1)R/((n + 1)R) = n, so n = 10.
Q5NEET 2018 · Q8
Unpolarised light is incident from air on a plane surface of a material of refractive index 'μ'. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?
Not quite — the answer is B.
This is Brewster's angle, tan i = μ, at which the reflected light is completely plane polarised with its electric vector perpendicular to the plane of incidence. The expression with tan⁻¹(1/μ) inverts Brewster's law, and sin⁻¹(1/μ) is the critical angle.
Q6NEET 2018 · Q9
In Young's double slit experiment the separation d between the slits is 2 mm, the wavelength λ of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same λ and D) the separation between the slits needs to be changed to
Not quite — the answer is B.
Angular fringe width θ = λ/d, so θ ∝ 1/d. d′ = d × 0.20/0.21 = 2 × 0.952 ≈ 1.9 mm. Increasing d to 2.1 mm would narrow the fringes instead.
Q7NEET 2018 · Q10
An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of
Not quite — the answer is A.
Magnification m = f₀/fₑ grows with the objective's focal length, and resolving power ∝ D/λ grows with its aperture. So the objective should have both a large focal length and a large diameter; a small aperture would worsen resolution.
Q8NEET 2018 · Q11
The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is
Not quite — the answer is B.
In a Bohr orbit, K = ke²/2r and the total energy E = −ke²/2r, so E = −K and K : E = 1 : −1. The ratio 1 : −2 is kinetic to potential energy, not to total energy.
Q9NEET 2018 · Q12
An electron of mass m with an initial velocity V⃗ = V₀î (V₀ > 0) enters an electric field E⃗ = −E₀î (E₀ = constant > 0) at t = 0. If λ₀ is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is
Not quite — the answer is C.
Force on the electron F = −eE⃗ = +eE₀î, along its velocity, so v = V₀ + eE₀t/m. Since λ = h/mv, λ = λ₀/(1 + eE₀t/(mV₀)); the wavelength decreases, so the expression that multiplies λ₀ by the growing factor is wrong.
Q10NEET 2018 · Q13
For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in minutes) for the disintegration of 450 nuclei is
Not quite — the answer is C.
After 450 decay, 150 of 600 remain, i.e. 1/4 = (1/2)². That is two half-lives = 20 minutes. 30 minutes would leave only 75 nuclei.
Q11NEET 2018 · Q14
When the light of frequency 2ν₀ (where ν₀ is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is v₁. When the frequency of the incident radiation is increased to 5ν₀, the maximum velocity of electrons emitted from the same plate is v₂. The ratio of v₁ to v₂ is
Not quite — the answer is C.
½mv₁² = h(2ν₀ − ν₀) = hν₀ and ½mv₂² = h(5ν₀ − ν₀) = 4hν₀. So v₁²/v₂² = 1/4 and v₁ : v₂ = 1 : 2; 1 : 4 is the ratio of kinetic energies, not speeds.
Q12NEET 2018 · Q16
In a p-n junction diode, change in temperature due to heating
Not quite — the answer is D.
Heating generates more electron–hole pairs, which changes the reverse saturation current, the barrier potential and the forward current. Hence both forward and reverse behaviour, i.e. the whole V–I characteristic, change; it is not limited to one bias direction.
Q13NEET 2018 · Q18
An em wave is propagating in a medium with a velocity V⃗ = Vî. The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along
Not quite — the answer is B.
The direction of propagation is along E⃗ × B⃗. With E⃗ along ĵ and propagation along î, B⃗ must be along k̂ because ĵ × k̂ = î. Choosing −z would reverse the propagation direction.
Q14NEET 2018 · Q19
The refractive index of the material of a prism is √2 and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror inwards, by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface) if its angle of incidence on the prism is
Not quite — the answer is B.
To retrace its path the ray must hit the silvered face normally, so r₂ = 0 and r₁ = A = 30°. By Snell's law sin i = √2 sin 30° = 1/√2, so i = 45°. Zero incidence would make the ray strike the silvered face at 30°, not normally.
Q15NEET 2018 · Q20
An object is placed at a distance of 40 cm from a concave mirror of focal length 15 cm. If the object is displaced through a distance of 20 cm towards the mirror, the displacement of the image will be
Not quite — the answer is B.
With u = −40 cm, f = −15 cm: 1/v = −1/15 + 1/40 gives v = −24 cm. With u = −20 cm: 1/v = −1/15 + 1/20 gives v = −60 cm. The image moves from 24 cm to 60 cm, i.e. 36 cm away from the mirror.
Q16NEET 2018 · Q21
The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance
Not quite — the answer is D.
U = ½LI², so L = 2U/I² = 2 × 25 × 10⁻³/(60 × 10⁻³)² = 0.05/0.0036 ≈ 13.89 H. Forgetting to square the current or the factor 2 gives the other values.
Q17NEET 2018 · Q22
An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is
Not quite — the answer is C.
In both cases the electric force is downward with magnitude eE, so each accelerates at a = eE/m (plus g). Since t = √(2h/a) and the electron's mass is far smaller, its acceleration is much larger and its time of fall is smaller. The times are not equal because the masses differ.
Q18NEET 2018 · Q23
The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is
Not quite — the answer is C.
Each plate sits in the uniform field σ/2ε₀ of the other, so F = Q²/(2ε₀A), which contains no separation term. For an isolated capacitor Q is fixed, so the force does not change with distance.
Q19NEET 2018 · Q24
A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperature of 27°C two successive resonances are produced at 20 cm and 73 cm of column length. If the frequency of the tuning fork is 320 Hz, the velocity of sound in air at 27°C is
Not quite — the answer is B.
Successive resonance lengths differ by λ/2: 73 − 20 = 53 cm, so λ = 1.06 m. v = fλ = 320 × 1.06 ≈ 339 m/s. Using 4 × 20 cm (ignoring end correction) would give a wrong value.
Q20NEET 2018 · Q25
A pendulum is hung from the roof of a sufficiently high building and is moving freely to and fro like a simple harmonic oscillator. The acceleration of the bob of the pendulum is 20 m/s² at a distance of 5 m from the mean position. The time period of oscillation is
Not quite — the answer is B.
In SHM a = ω²x, so ω² = 20/5 = 4 and ω = 2 rad/s. T = 2π/ω = π s; 2π s would correspond to ω = 1 rad/s.
Q21NEET 2018 · Q26
A metallic rod of mass per unit length 0.5 kg m⁻¹ is lying horizontally on a smooth inclined plane which makes an angle of 30° with the horizontal. The rod is not allowed to slide down by flowing a current through it when a magnetic field of induction 0.25 T is acting on it in the vertical direction. The current flowing in the rod to keep it stationary is
Not quite — the answer is D.
The magnetic force BIl is horizontal; balancing components along the incline: BIl cos 30° = mg sin 30°. I = (m/l)g tan 30°/B = 0.5 × 9.8 × 0.577/0.25 ≈ 11.32 A. Taking the force along the incline (without the cos 30°) would give a smaller current.
Q22NEET 2018 · Q28
An inductor 20 mH, a capacitor 100 μF and a resistor 50 Ω are connected in series across a source of emf, V = 10 sin 314 t. The power loss in the circuit is
Not quite — the answer is C.
X_L = 314 × 0.02 = 6.28 Ω, X_C = 1/(314 × 10⁻⁴) = 31.85 Ω, Z = √(50² + 25.57²) ≈ 56.2 Ω. I_rms = (10/√2)/56.2 ≈ 0.126 A, so P = I_rms²R ≈ 0.79 W. Using peak instead of rms current doubles the power.
Q23NEET 2018 · Q29
Current sensitivity of a moving coil galvanometer is 5 div/mA and its voltage sensitivity (angular deflection per unit voltage applied) is 20 div/V. The resistance of the galvanometer is
Not quite — the answer is A.
Voltage sensitivity = current sensitivity / G, so G = (5 div/mA)/(20 div/V) = (5000 div/A)/(20 div/V) = 250 Ω. Forgetting the mA-to-A conversion gives 0.25 Ω-type answers.
Q24NEET 2018 · Q31
Three objects, A : (a solid sphere), B : (a thin circular disk) and C : (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed ω about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation
Not quite — the answer is C.
Work needed equals the rotational KE ½Iω². I_ring = MR² > I_disc = MR²/2 > I_sphere = 2MR²/5, so W_C > W_B > W_A. The sphere needs the least because its mass is closest to the axis.
Q25NEET 2018 · Q32
A moving block having mass m, collides with another stationary block having mass 4m. The lighter block comes to rest after collision. When the initial velocity of the lighter block is v, then the value of coefficient of restitution (e) will be
Not quite — the answer is B.
Momentum: mv = 4mv′, so v′ = v/4. e = (relative speed of separation)/(relative speed of approach) = (v/4 − 0)/v = 0.25. A value of 0.8 would not conserve momentum with the lighter block stopping.
Q26NEET 2018 · Q33
Which one of the following statements is incorrect?
Not quite — the answer is D.
The coefficient of friction is a ratio of two forces (friction/normal reaction), so it is dimensionless; the statement that it has dimensions of length is wrong. The other statements are standard properties of friction.
Q27NEET 2018 · Q34
A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field E⃗. Due to the force qE⃗, its velocity increases from 0 to 6 m/s in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively
Not quite — the answer is B.
a = 6 m/s². 0–1 s: 3 m forward. 1–2 s: decelerates from 6 to 0, another 3 m forward. 2–3 s: accelerates backward from rest, 3 m back. Net displacement 3 m and distance 9 m in 3 s, so average velocity 1 m/s and average speed 3 m/s.
Q28NEET 2018 · Q36
The moment of the force, F⃗ = 4î + 5ĵ − 6k̂ at (2, 0, −3), about the point (2, −2, −2), is given by
Not quite — the answer is D.
r⃗ = (2, 0, −3) − (2, −2, −2) = 2ĵ − k̂. τ⃗ = r⃗ × F⃗ = î(2·(−6) − (−1)·5) − ĵ(0·(−6) − (−1)·4) + k̂(0·5 − 2·4) = −7î − 4ĵ − 8k̂. The other vectors have the components permuted.
Q29NEET 2018 · Q37
A student measured the diameter of a small steel ball using a screw gauge of least count 0.001 cm. The main scale reading is 5 mm and zero of circular scale division coincides with 25 divisions above the reference level. If screw gauge has a zero error of −0.004 cm, the correct diameter of the ball is
Not quite — the answer is D.
Observed reading = 0.5 cm + 25 × 0.001 cm = 0.525 cm. Correct reading = observed − zero error = 0.525 − (−0.004) = 0.529 cm. Adding the negative zero error with the wrong sign gives 0.521 cm.
Q30NEET 2018 · Q38
A solid sphere is rotating freely about its symmetry axis in free space. The radius of the sphere is increased keeping its mass same. Which of the following physical quantities would remain constant for the sphere?
Not quite — the answer is D.
In free space there is no external torque, so angular momentum L = Iω is conserved. Increasing the radius raises I, so ω falls and the rotational KE L²/2I also falls.
Q31NEET 2018 · Q40
If the mass of the Sun were ten times smaller and the universal gravitational constant were ten times larger in magnitude, which of the following is not correct?
Not quite — the answer is D.
g = GM_E/R² depends on G and the Earth's mass, not the Sun's. With G ten times larger, g becomes ten times larger, so the claim that g stays the same is wrong; the larger g also shortens the pendulum period and makes raindrops fall faster.
Q32NEET 2018 · Q41
A solid sphere is in rolling motion. In rolling motion a body possesses translational kinetic energy (K_t) as well as rotational kinetic energy (K_r) simultaneously. The ratio K_t : (K_t + K_r) for the sphere is
Not quite — the answer is B.
K_t = ½mv², K_r = ½(2/5 mR²)(v/R)² = (1/5)mv². K_t : (K_t + K_r) = ½ : (7/10) = 5 : 7. The ratio 2 : 5 is K_r : K_t.
Q33NEET 2018 · Q42
A small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to
Not quite — the answer is A.
At terminal velocity the heating rate equals F·v = 6πηrv·v. Since v_t ∝ r², power ∝ r × r⁴ = r⁵. Taking only the force (∝ r³ at terminal speed) misses the extra factor of velocity.
Q34NEET 2018 · Q43
The power radiated by a black body is P and it radiates maximum energy at wavelength, λ₀. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength (3/4)λ₀, the power radiated by it becomes nP. The value of n is
Not quite — the answer is A.
Wien's law λ_mT = constant gives T′ = (4/3)T. By Stefan's law P ∝ T⁴, so n = (4/3)⁴ = 256/81. The inverse 81/256 would correspond to cooling, not heating.
Q35NEET 2018 · Q44
Two wires are made of the same material and have the same volume. The first wire has cross-sectional area A and the second wire has cross-sectional area 3A. If the length of the first wire is increased by Δl on applying a force F, how much force is needed to stretch the second wire by the same amount?
Not quite — the answer is C.
F = YAΔl/L. Equal volume means the second wire has length L/3. F′ = Y(3A)Δl/(L/3) = 9 × YAΔl/L = 9F. Considering only the area change would give 3F.
Q36NEET 2018 · Q45
A sample of 0.1 g of water at 100°C and normal pressure (1.013 × 10⁵ N m⁻²) requires 54 cal of heat energy to convert to steam at 100°C. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is
Not quite — the answer is B.
Q = 54 cal ≈ 54 × 4.18 ≈ 225.7 J. Work by the vapour W = PΔV = 1.013 × 10⁵ × (167.1 − 0.1) × 10⁻⁶ ≈ 16.9 J. ΔU = Q − W ≈ 208.8 J ≈ 208.7 J.
Chapter-wise split of NEET 2018 Physics
- System of Particles and Rotational Motion4 Q
- Ray Optics and Optical Instruments3 Q
- Thermodynamics2 Q
- Current Electricity2 Q
- Wave Optics2 Q
- Dual Nature of Radiation and Matter2 Q
- Moving Charges and Magnetism2 Q
- Kinetic Theory1 Q
- Atoms1 Q
- Nuclei1 Q
- Semiconductor Electronics: Materials, Devices and Simple Circuits1 Q
- Electromagnetic Waves1 Q
- Electromagnetic Induction1 Q
- Electric Charges and Fields1 Q
- Electrostatic Potential and Capacitance1 Q
- Waves1 Q
- Oscillations1 Q
- Alternating Current1 Q
- Work, Energy and Power1 Q
- Laws of Motion1 Q
- Motion in a Straight Line1 Q
- Units and Measurements1 Q
- Gravitation1 Q
- Mechanical Properties of Fluids1 Q
- Thermal Properties of Matter1 Q
- Mechanical Properties of Solids1 Q
NEET 2018 Chemistry questions
33 questions. Tap an option to check your answer.
Q1NEET 2018 · Q46
The correct order of N-compounds in its decreasing order of oxidation states is
Not quite — the answer is C.
Oxidation states of N: HNO₃ +5, NO +2, N₂ 0, NH₄Cl −3. So the decreasing order is HNO₃ > NO > N₂ > NH₄Cl; the reverse sequence is increasing order.
Q2NEET 2018 · Q47
Which one of the following elements is unable to form MF₆³⁻ ion?
Not quite — the answer is A.
Boron has no d orbitals in its valence shell, so its maximum covalency is 4 (as in BF₄⁻). Al, Ga and In can use d orbitals to expand to six-coordination, giving MF₆³⁻.
Q3NEET 2018 · Q49
The correct order of atomic radii in group 13 elements is
Not quite — the answer is D.
Ga (135 pm) is slightly smaller than Al (143 pm) because the poorly shielding 3d electrons raise its effective nuclear charge. In (167 pm) and Tl (170 pm) follow, so B < Ga < Al < In < Tl. The simple monotonic order ignores this anomaly.
Q4NEET 2018 · Q51
In the structure of ClF₃, the number of lone pairs of electrons on central atom 'Cl' is
Not quite — the answer is B.
Cl has 7 valence electrons; 3 form bonds with F, leaving 4 electrons = 2 lone pairs. Five electron pairs give a trigonal bipyramidal arrangement with the two lone pairs equatorial, hence the T-shape.
Q5NEET 2018 · Q52
Identify the major products P, Q and R in the following sequence of reactions: Benzene + CH₃CH₂CH₂Cl —(Anhydrous AlCl₃)→ P; P —(i) O₂, (ii) H₃O⁺/Δ→ Q + R
Not quite — the answer is D.
In Friedel–Crafts alkylation the n-propyl carbocation rearranges to the more stable isopropyl cation, giving cumene. Air oxidation gives cumene hydroperoxide, which on acid hydrolysis gives phenol and acetone (not propan-2-ol).
Q6NEET 2018 · Q53
Which of the following compounds can form a zwitterion?
Not quite — the answer is D.
Glycine has both an acidic –COOH and a basic –NH₂ group, so an internal proton transfer gives H₃N⁺–CH₂–COO⁻. Benzoic acid and aniline have only one of these groups, and the N in acetanilide is not basic.
Q7NEET 2018 · Q55
Nitration of aniline in strong acidic medium also gives m-nitroaniline because
Not quite — the answer is D.
In strongly acidic nitrating mixture, aniline is protonated to the anilinium ion C₆H₅NH₃⁺, whose –NH₃⁺ group is electron-withdrawing and meta-directing. The free –NH₂ group itself is ortho/para-directing.
Q8NEET 2018 · Q56
The difference between amylose and amylopectin is
Not quite — the answer is C.
Amylose is an unbranched chain of α-D-glucose with C1→C4 α-glycosidic links. Amylopectin is branched: C1→C4 α-links in the chain and C1→C6 α-links at branch points. Starch has no β-links, and amylose contains only glucose.
Q9NEET 2018 · Q57
A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H₂SO₄. The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be
Not quite — the answer is A.
HCOOH (2.3/46 = 0.05 mol) → CO + H₂O; H₂C₂O₄ (4.5/90 = 0.05 mol) → CO + CO₂ + H₂O. KOH absorbs CO₂ (and water), leaving 0.1 mol CO = 0.1 × 28 = 2.8 g. 4.4 g would be the CO₂ mass if it were wrongly counted.
Q10NEET 2018 · Q58
Which of the following oxides is most acidic in nature?
Not quite — the answer is B.
Down group 2 metallic character increases, so the oxides become more basic: BeO < MgO < CaO < BaO in basicity. BeO is amphoteric and thus the most acidic; BaO is the most basic.
Q11NEET 2018 · Q60
The compound A on treatment with Na gives B, and with PCl₅ gives C. B and C react together to give diethyl ether. A, B and C are in the order
Not quite — the answer is D.
Ethanol with Na gives sodium ethoxide; with PCl₅ it gives chloroethane. Williamson synthesis C₂H₅ONa + C₂H₅Cl → C₂H₅OC₂H₅. Na does not convert ethanol to ethane, and the order of B and C matters.
Q12NEET 2018 · Q61
The compound C₇H₈ undergoes the following reactions: C₇H₈ —(3Cl₂/Δ)→ A —(Br₂/Fe)→ B —(Zn/HCl)→ C. The product 'C' is
Not quite — the answer is C.
Toluene with Cl₂ under heat (side-chain chlorination) gives C₆H₅CCl₃. The –CCl₃ group is electron-withdrawing and meta-directing, so Br₂/Fe gives m-bromobenzotrichloride; Zn/HCl reduces –CCl₃ back to –CH₃, giving m-bromotoluene. Direct bromination of toluene would give the ortho/para products.
Q13NEET 2018 · Q62
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
Not quite — the answer is D.
CH₄ + Br₂ → CH₃Br; Wurtz coupling 2CH₃Br + 2Na → C₂H₆, a gas with fewer than four carbons. Ethane would give butane (four carbons), and ethene/ethyne add bromine rather than substitute.
Q14NEET 2018 · Q63
Which of the following molecules represents the order of hybridisation sp², sp², sp, sp from left to right atoms?
Not quite — the answer is B.
In CH₂=CH–C≡CH the two doubly bonded carbons are sp² and the two triply bonded carbons are sp. Buta-1,3-diene is all sp², and but-2-ene has sp³ end carbons.
Q15NEET 2018 · Q66
In the reaction: phenol + CHCl₃ + NaOH → sodium salt of o-hydroxybenzaldehyde (o-formyl sodium phenoxide, O⁻Na⁺ with –CHO at the ortho position), the electrophile involved is
Not quite — the answer is D.
In the Reimer–Tiemann reaction, OH⁻ removes a proton from CHCl₃ and the ⁻CCl₃ loses Cl⁻ to give dichlorocarbene :CCl₂, an electron-deficient electrophile that attacks the phenoxide ring at the ortho position. The dichloromethyl anion is a nucleophile, not an electrophile.
Q16NEET 2018 · Q67
Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their
Not quite — the answer is D.
Carboxylic acids form strong intermolecular hydrogen bonds and exist as dimers even in the vapour phase, raising the boiling point. Intramolecular H-bonding would lower, not raise, the boiling point.
Q17NEET 2018 · Q68
Compound A, C₈H₁₀O, is found to react with NaOI (produced by reacting Y with NaOH) and yields a yellow precipitate with characteristic smell. A and Y are respectively
Not quite — the answer is A.
The yellow precipitate with antiseptic smell is iodoform, formed by NaOI (from I₂ + NaOH). It requires a CH₃CH(OH)– or CH₃CO– unit; 1-phenylethanol has it, while 2-phenylethanol, p-methylbenzyl alcohol and the dimethylphenol do not.
Q18NEET 2018 · Q69
Match the metal ions given in Column I with the spin magnetic moments of the ions given in Column II and assign the correct code: Column I: a. Co³⁺ b. Cr³⁺ c. Fe³⁺ d. Ni²⁺; Column II: i. √8 B.M. ii. √35 B.M. iii. √3 B.M. iv. √24 B.M. v. √15 B.M.
Not quite — the answer is C.
μ = √(n(n+2)): Co³⁺ (3d⁶, 4 unpaired) √24; Cr³⁺ (3d³, 3 unpaired) √15; Fe³⁺ (3d⁵, 5 unpaired) √35; Ni²⁺ (3d⁸, 2 unpaired) √8. Matching Ni²⁺ with √3 would assume only one unpaired electron.
Q19NEET 2018 · Q70
Which one of the following ions exhibits d-d transition and paramagnetism as well?
Not quite — the answer is D.
In MnO₄²⁻ manganese is +6 (3d¹): one unpaired electron makes it paramagnetic and allows d-d transitions. MnO₄⁻ (Mn⁺⁷), Cr₂O₇²⁻ and CrO₄²⁻ (Cr⁺⁶) are d⁰ and diamagnetic; their colour is due to charge transfer.
Q20NEET 2018 · Q71
Iron carbonyl, Fe(CO)₅ is
Not quite — the answer is B.
Fe(CO)₅ contains a single Fe atom bonded to five CO ligands, so it is mononuclear (trigonal bipyramidal). Fe₂(CO)₉ is the dinuclear and Fe₃(CO)₁₂ the trinuclear carbonyl.
Q21NEET 2018 · Q72
The type of isomerism shown by the complex [CoCl₂(en)₂] is
Not quite — the answer is C.
The octahedral [MA₂(AA)₂] complex can have the two Cl ligands cis or trans, so it shows geometrical isomerism (the cis form is also optically active). It has no counter-ion exchange, no complex cation–anion pair and no ambidentate ligand, so the other types do not apply.
Q22NEET 2018 · Q73
The geometry and magnetic behaviour of the complex [Ni(CO)₄] are
Not quite — the answer is B.
Ni is in the 0 state (3d⁸4s²); the strong-field CO ligands pair all electrons into 3d¹⁰, and sp³ hybridisation gives a tetrahedral, diamagnetic complex. Square planar dsp² geometry is for Ni²⁺ with strong-field ligands like CN⁻.
Q23NEET 2018 · Q74
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations: a. 60 mL M/10 HCl + 40 mL M/10 NaOH b. 55 mL M/10 HCl + 45 mL M/10 NaOH c. 75 mL M/5 HCl + 25 mL M/5 NaOH d. 100 mL M/10 HCl + 100 mL M/10 NaOH. pH of which one of them will be equal to 1?
Not quite — the answer is D.
For c: HCl = 75 × 0.2 = 15 mmol, NaOH = 25 × 0.2 = 5 mmol; excess H⁺ = 10 mmol in 100 mL = 0.1 M, so pH = 1. Mixture a leaves 0.02 M H⁺, b leaves 0.01 M H⁺, and d is exactly neutral.
Q24NEET 2018 · Q77
The solubility of BaSO₄ in water is 2.42 × 10⁻³ g L⁻¹ at 298 K. The value of its solubility product (K_sp) will be (Given molar mass of BaSO₄ = 233 g mol⁻¹)
Not quite — the answer is C.
Molar solubility s = 2.42 × 10⁻³/233 = 1.04 × 10⁻⁵ mol L⁻¹. For BaSO₄ ⇌ Ba²⁺ + SO₄²⁻, K_sp = s² = 1.08 × 10⁻¹⁰ mol² L⁻². Squaring the gram solubility without converting to moles gives a wrong exponent.
Q25NEET 2018 · Q78
In which case is the number of molecules of water maximum?
Not quite — the answer is C.
18 mL of liquid water (density 1 g/mL) is 18 g = 1 mol. The others are 10⁻⁴ mol (0.00224 L of vapour at STP), 0.01 mol (0.18 g) and 10⁻³ mol, so 18 mL has the most molecules.
Q26NEET 2018 · Q79
The correct difference between first- and second-order reactions is that
Not quite — the answer is B.
For first order t½ = 0.693/k, independent of [A]₀, while for second order t½ = 1/(k[A]₀). Rates of both orders depend on concentration, and either type can be catalysed.
Q27NEET 2018 · Q82
For the redox reaction MnO₄⁻ + C₂O₄²⁻ + H⁺ → Mn²⁺ + CO₂ + H₂O, the correct coefficients of the reactants for the balanced equation are (MnO₄⁻, C₂O₄²⁻, H⁺)
Not quite — the answer is B.
Mn goes from +7 to +2 (gain 5e⁻) and each C₂O₄²⁻ loses 2e⁻. Equalising electrons: 2MnO₄⁻ + 5C₂O₄²⁻; balancing O and H gives 2MnO₄⁻ + 5C₂O₄²⁻ + 16H⁺ → 2Mn²⁺ + 10CO₂ + 8H₂O.
Q28NEET 2018 · Q83
Which one of the following conditions will favour maximum formation of the product in the reaction, A₂(g) + B₂(g) ⇌ X₂(g) ΔᵣH = −X kJ?
Not quite — the answer is C.
The forward reaction is exothermic, so low temperature favours the product. It also reduces gas moles from 2 to 1, so high pressure shifts equilibrium forward (Le Chatelier). High temperature would favour the reverse reaction.
Q29NEET 2018 · Q84
When initial concentration of the reactant is doubled, the half-life period of a zero order reaction
Not quite — the answer is B.
For a zero-order reaction t½ = [A]₀/2k, directly proportional to initial concentration, so doubling [A]₀ doubles t½. A half-life independent of concentration is the first-order case.
Q30NEET 2018 · Q85
The bond dissociation energies of X₂, Y₂ and XY are in the ratio of 1 : 0.5 : 1. ΔH for the formation of XY is −200 kJ mol⁻¹. The bond dissociation energy of X₂ will be
Not quite — the answer is A.
Let BE(X₂) = a, BE(Y₂) = 0.5a, BE(XY) = a. For ½X₂ + ½Y₂ → XY: ΔH = ½a + ¼a − a = −a/4 = −200, so a = 800 kJ mol⁻¹. Forgetting the ½ coefficients (forming 2XY) gives 400 kJ mol⁻¹.
Q31NEET 2018 · Q87
Consider the following species: CN⁺, CN⁻, NO and CN. Which one of these will have the highest bond order?
Not quite — the answer is B.
By MO theory: CN⁻ (14 electrons) has bond order 3; CN (13) and NO (15) have 2.5; CN⁺ (12) has 2. So CN⁻ has the highest bond order; removing an electron from CN lowers it.
Q32NEET 2018 · Q88
Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of (X) is 1s² 2s² 2p³, the simplest formula for this compound is
Not quite — the answer is D.
X is nitrogen, which gains 3 electrons to form N³⁻, while Mg forms Mg²⁺. Charge balance requires 3 Mg²⁺ for 2 N³⁻, giving Mg₃X₂ (magnesium nitride). Mg₂X₃ reverses the subscripts.
Q33NEET 2018 · Q90
Which one is a wrong statement?
Not quite — the answer is A.
By Hund's rule, the three unpaired 2p electrons of nitrogen must have parallel spins; the box diagram with one 2p electron spin-down is wrong. An s electron has l = 0 so zero orbital angular momentum, and d_z² corresponds to m = 0.
Chemistry: not in the current NEET syllabus
These 7 questions are from topics NCERT dropped in its 2023 revision. Shown for completeness; you can skip them for NEET 2027.
7 questions. Tap an option to check your answer.
Q1NEET 2018 · Q48
Considering Ellingham diagram, which of the following metals can be used to reduce alumina?
Not quite — the answer is A.
A metal can reduce an oxide if its own oxide line lies below in the Ellingham diagram (more negative ΔG°). The MgO line lies below Al₂O₃ at high temperature, so Mg can reduce alumina; Zn, Fe and Cu oxides lie above it.
Q2NEET 2018 · Q59
Which oxide of nitrogen is not a common pollutant introduced into the atmosphere both due to natural and human activity?
Not quite — the answer is C.
NO, NO₂ and N₂O are released both naturally (lightning, soil bacteria) and by combustion and fertilisers. N₂O₅ is an unstable solid anhydride and is not a common atmospheric pollutant.
Q3NEET 2018 · Q75
On which of the following properties does the coagulating power of an ion depend?
Not quite — the answer is A.
By the Hardy–Schulze rule, only ions of charge opposite to the colloid coagulate it (sign), and coagulating power increases sharply with the valency of that ion (magnitude). Neither factor alone is enough.
Q4NEET 2018 · Q76
Given van der Waals constant for NH₃, H₂, O₂ and CO₂ are respectively 4.17, 0.244, 1.36 and 3.59, which one of the following gases is most easily liquefied?
Not quite — the answer is C.
The van der Waals constant 'a' measures intermolecular attraction; the larger 'a', the higher the critical temperature and the easier the liquefaction. NH₃ has the largest value (4.17), H₂ the smallest.
Q5NEET 2018 · Q80
Among CaH₂, BeH₂, BaH₂, the order of ionic character is
Not quite — the answer is C.
Down group 2 the metal becomes larger and more electropositive, so ionic character of the hydrides increases: BeH₂ (covalent, polymeric) < CaH₂ < BaH₂. Placing BaH₂ below CaH₂ contradicts this trend.
Q6NEET 2018 · Q86
The correction factor 'a' to the ideal gas equation corresponds to
Not quite — the answer is D.
In the van der Waals equation (P + an²/V²)(V − nb) = nRT, the term with 'a' corrects the pressure for intermolecular attractive forces. The constant 'b' is the one that corrects for the volume of the molecules.
Q7NEET 2018 · Q89
Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of iron remains constant with temperature) is
Not quite — the answer is A.
ρ ∝ Z/a³. bcc: Z = 2, a = 4r/√3; fcc: Z = 4, a = 2√2 r. ρ_bcc/ρ_fcc = [2 × 3√3/(64r³)] / [4/(16√2 r³)] = 3√6/8 = 3√3/(4√2). The bcc form is less dense, so a ratio greater than 1 is wrong.
Chapter-wise split of NEET 2018 Chemistry
- Alcohols, Phenols and Ethers4 Q
- Chemical Bonding and Molecular Structure3 Q
- Coordination Compounds3 Q
- Equilibrium3 Q
- Redox Reactions2 Q
- Biomolecules2 Q
- Some Basic Concepts of Chemistry2 Q
- The d- and f-Block Elements2 Q
- Chemical Kinetics2 Q
- Amines1 Q
- Classification of Elements and Periodicity in Properties1 Q
- Haloalkanes and Haloarenes1 Q
- Hydrocarbons1 Q
- Organic Chemistry: Some Basic Principles and Techniques1 Q
- Aldehydes, Ketones and Carboxylic Acids1 Q
- Thermodynamics1 Q
- Structure of Atom1 Q
NEET 2018 Biology questions
73 questions. Tap an option to check your answer.
Q1NEET 2018 · Q91
Oxygen is not produced during photosynthesis by
Not quite — the answer is C.
Green sulphur bacteria carry out anoxygenic photosynthesis: they use H₂S rather than water as the electron donor, so sulphur, not oxygen, is released. Nostoc is a cyanobacterium and, like Cycas and Chara, splits water and evolves oxygen.
Q2NEET 2018 · Q92
Double fertilization is
Not quite — the answer is D.
In angiosperms one male gamete fuses with the egg (syngamy) and the other fuses with the two polar nuclei (triple fusion); the two fusions together in one embryo sac are called double fertilization. Fusion of one male gamete with the polar nuclei is only triple fusion, one half of the process.
Q3NEET 2018 · Q93
Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
Not quite — the answer is B.
Yucca is pollinated only by the yucca moth, which lays its eggs in the ovary of the flower; the larvae feed on some developing seeds. The plant cannot set seed without the moth and the moth cannot complete its life cycle without the flower. Hydrilla is water-pollinated and Viola has cleistogamous flowers.
Q4NEET 2018 · Q94
Pollen grains can be stored for several years in liquid nitrogen having a temperature of
Not quite — the answer is A.
Liquid nitrogen boils at about −196°C, and pollen cryopreserved at this temperature stays viable for years, forming pollen banks used in crop breeding. The other temperatures are not the temperature of liquid nitrogen.
Q5NEET 2018 · Q96
What is the role of NAD⁺ in cellular respiration?
Not quite — the answer is B.
NAD⁺ is a coenzyme that accepts electrons and hydrogen during glycolysis and the Krebs cycle, becoming NADH, and hands them to the electron transport chain. It is not an enzyme itself, and it is not a final electron acceptor; NADH is reoxidised during fermentation but the final acceptor there is an organic molecule such as pyruvate or acetaldehyde.
Q6NEET 2018 · Q98
Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes?
Not quite — the answer is C.
In gene therapy (for example ADA deficiency), a functional gene is put into a patient's lymphocytes using a disarmed retroviral vector, because retroviruses integrate their DNA into the host genome. λ phage and pBR322 are vectors for bacteria and the Ti plasmid is used for plants.
Q7NEET 2018 · Q99
Use of bioresources by multinational companies and organisations without authorisation from the concerned country and its people is called
Not quite — the answer is B.
Biopiracy is the use of a country's bioresources and traditional knowledge by multinational companies without proper authorisation or compensation to the country and its people. Biodegradation is breakdown of matter by microbes, and the other two terms are not the standard name for this practice.
Q8NEET 2018 · Q100
In India, the organisation responsible for assessing the safety of introducing genetically modified organisms for public use is
Not quite — the answer is D.
The Indian Government set up GEAC to decide on the validity of GM research and the safety of introducing GM organisms for public services. RCGM oversees research-level work, while CSIR and ICMR are general research councils.
Q9NEET 2018 · Q101
The correct order of steps in Polymerase Chain Reaction (PCR) is
Not quite — the answer is D.
Each PCR cycle first denatures double-stranded DNA by heat, then lets the primers anneal to the single strands at a lower temperature, and finally Taq polymerase extends the primers. Extension cannot happen before annealing because the polymerase needs a primer to start from.
Q10NEET 2018 · Q102
Select the correct match:
Not quite — the answer is C.
A ribozyme is a catalytic RNA, such as the peptidyl transferase activity of rRNA, so it is a nucleic acid. Morgan is linked with linkage, a cross of the F₂ (or F₁) with the recessive parent is a test cross, and transformation was discovered by Griffith, not Mendel.
Q11NEET 2018 · Q103
A 'new' variety of rice was patented by a foreign company, though such varieties have been present in India for a long time. This is related to
Not quite — the answer is D.
In 1997 an American company obtained a patent on a Basmati-derived rice, although Basmati varieties have been grown in India for centuries; NCERT cites it as an example of biopiracy. Lerma Rojo and Sharbati Sonora are wheat varieties and Co-667 is a sugarcane variety.
Q12NEET 2018 · Q104
Which of the following pairs is wrongly matched?
Not quite — the answer is C.
Starch synthesis in pea is controlled by one gene with two alleles (B and b); it is NCERT's example of incomplete dominance at the level of starch grain size and of pleiotropy, not of multiple alleles. Grasshopper has XO sex determination, the Iᴬ and Iᴮ alleles of ABO are co-dominant and Morgan worked out linkage.
Q13NEET 2018 · Q105
Select the correct statement:
Not quite — the answer is B.
The Punnett square is named after Reginald C. Punnett, a British geneticist. Spliceosomes act in splicing of hnRNA, not translation; Morgan coined the term linkage; and transduction was discovered by Zinder and Lederberg, while Altman is known for ribozymes.
Q14NEET 2018 · Q106
The experimental proof for semiconservative replication of DNA was first shown in a
Not quite — the answer is B.
Meselson and Stahl (1958) grew Escherichia coli in ¹⁵N medium and then ¹⁴N medium and showed hybrid and light DNA by density gradient centrifugation, the first proof of semiconservative replication. Taylor later showed the same in Vicia faba, a plant, so the plant option is the later, not the first, proof.
Q15NEET 2018 · Q109
Select the correct match:
Not quite — the answer is D.
Jacob and Monod proposed the lac operon model of gene regulation in E. coli. Meselson and Stahl worked on E. coli, Hershey and Chase used bacteriophage T2, and Alec Jeffreys developed DNA fingerprinting; Streptococcus pneumoniae was Griffith's organism.
Q16NEET 2018 · Q110
Which of the following has proved helpful in preserving pollen as fossils?
Not quite — the answer is D.
The exine of pollen is made of sporopollenin, one of the most resistant organic materials, which withstands high temperature, strong acids and alkalis and is not degraded by enzymes, so pollen is well preserved as fossils. The intine is thin cellulose-pectin and pollenkitt is a sticky oily coat; neither survives.
Q17NEET 2018 · Q111
Natality refers to
Not quite — the answer is B.
Natality is the number of births in a population during a given period, i.e. the birth rate, and it adds to population density. Individuals leaving the habitat is emigration, individuals entering is immigration, and the death rate is mortality.
Q18NEET 2018 · Q114
Niche is
Not quite — the answer is D.
An ecological niche is the functional role of an organism in its habitat, including the range of conditions it tolerates and the resources it uses. The physical space where it lives is its habitat, and a temperature range alone is only one dimension of the niche.
Q19NEET 2018 · Q115
What type of ecological pyramid would be obtained with the following data? Secondary consumer : 120 g Primary consumer : 60 g Primary producer : 10 g
Not quite — the answer is C.
The data are masses (biomass), and they increase from producers (10 g) to primary consumers (60 g) to secondary consumers (120 g), so the base is the narrowest level and the pyramid of biomass is inverted, as in some aquatic ecosystems. Grams are not numbers of individuals or energy units, so the other pyramid types do not fit.
Q20NEET 2018 · Q117
The two functional groups characteristic of sugars are
Not quite — the answer is D.
Sugars are polyhydroxy aldehydes or ketones, so they carry several hydroxyl groups and one carbonyl group (aldehyde or keto). Phosphate occurs only in sugar phosphates and nucleotides, and a methyl group is not characteristic of sugars.
Q21NEET 2018 · Q118
Which among the following is not a prokaryote?
Not quite — the answer is C.
Saccharomyces is yeast, a unicellular fungus with a true nucleus, so it is a eukaryote. Nostoc and Oscillatoria are cyanobacteria and Mycobacterium is a bacterium, all prokaryotes.
Q22NEET 2018 · Q119
The Golgi complex participates in
Not quite — the answer is B.
The Golgi apparatus packages and modifies materials received from the ER and buds them off as secretory vesicles from its trans face. Bacteria have no Golgi, fatty acid breakdown occurs in mitochondria and peroxisomes, and amino acid activation occurs in the cytoplasm by aminoacyl-tRNA synthetases.
Q23NEET 2018 · Q120
Which of the following is not a product of light reaction of photosynthesis?
Not quite — the answer is B.
The light reaction produces ATP, NADPH and O₂ (from photolysis of water). NADH is a product of respiration (glycolysis and the Krebs cycle), not of photosynthesis.
Q24NEET 2018 · Q121
Which of the following is true for nucleolus?
Not quite — the answer is D.
The nucleolus is a non-membrane-bound body in the nucleus where rRNA is actively synthesised. It is not membrane-bound, it disappears during cell division instead of forming the spindle, and larger, more numerous nucleoli occur in cells actively making proteins, not specifically in dividing cells.
Q25NEET 2018 · Q123
The stage during which separation of the paired homologous chromosomes begins is
Not quite — the answer is B.
In diplotene the synaptonemal complex dissolves and the homologous chromosomes of each bivalent begin to separate, remaining joined only at the chiasmata. Pairing (synapsis) occurs in zygotene and crossing over in pachytene, while in diakinesis the chiasmata terminalise.
Q26NEET 2018 · Q124
Stomata in grass leaf are
Not quite — the answer is C.
In grasses (monocots) the guard cells are dumb-bell shaped. Kidney (bean) shaped guard cells are typical of dicot leaves, which is the main trap.
Q27NEET 2018 · Q125
Secondary xylem and phloem in dicot stem are produced by
Not quite — the answer is B.
The vascular cambium is a lateral meristem that cuts off secondary xylem towards the inside and secondary phloem towards the outside. Phellogen (cork cambium) forms cork and secondary cortex, while apical and axillary meristems produce primary tissues.
Q28NEET 2018 · Q126
Pneumatophores occur in
Not quite — the answer is C.
Pneumatophores are negatively geotropic respiratory roots of mangroves such as Rhizophora, which are halophytes growing in waterlogged saline swamps where the soil is poor in oxygen. Hydrophytes take oxygen directly from the water or air and do not need them.
Q29NEET 2018 · Q127
Casparian strips occur in
Not quite — the answer is D.
The tangential and radial walls of root endodermal cells carry a band of suberin called the Casparian strip, which blocks the apoplastic movement of water. The pericycle lies just inside the endodermis but has no such strips.
Q30NEET 2018 · Q128
Plants having little or no secondary growth are
Not quite — the answer is C.
Grasses are monocots with closed vascular bundles that lack cambium, so they show little or no secondary growth. Conifers and deciduous dicot trees have an active vascular cambium and form wood; cycads also show secondary growth.
Q31NEET 2018 · Q129
Sweet potato is a modified
Not quite — the answer is B.
The edible part of sweet potato is a swollen adventitious root that stores food. It is not a stem or rhizome, unlike potato (a stem tuber), and it is not a tap root like carrot or radish.
Q32NEET 2018 · Q130
Which of the following statements is correct?
Not quite — the answer is C.
Gymnosperms have naked ovules that are not enclosed in an ovary, which is the basis of their name. Horsetails (Equisetum) are pteridophytes, both Selaginella and Salvinia are heterosporous, and Cedrus has a branched stem although Cycas is unbranched.
Q33NEET 2018 · Q131
Select the wrong statement:
Not quite — the answer is A.
Sporozoans such as Plasmodium have no locomotory structures; pseudopodia are found in amoeboid protozoans (sarcodines). Mushrooms are basidiomycetes, fungi and plants have cell walls, and Monera lack mitochondria while all other kingdoms have them.
Q34NEET 2018 · Q132
After karyogamy followed by meiosis, spores are produced exogenously in
Not quite — the answer is A.
In Agaricus (a basidiomycete) karyogamy and meiosis occur in the basidium and the four basidiospores are borne exogenously on it. In Neurospora and Saccharomyces (ascomycetes) the meiospores form endogenously in an ascus, and Alternaria is a deuteromycete with no known sexual stage.
Q35NEET 2018 · Q134
Winged pollen grains are present in
Not quite — the answer is D.
Pinus pollen grains have two air-filled wings (sacs) that help in wind dispersal. Cycas pollen is wingless, and mango and mustard are angiosperms with ordinary pollen.
Q36NEET 2018 · Q135
Which one is wrongly matched?
Not quite — the answer is C.
Polysiphonia is a red alga, and red algae have no flagellated cells at any stage, so pairing it with uniflagellate gametes is the wrong match. Chlorella is indeed a unicellular green alga, Marchantia bears gemma cups and brown algae produce pear-shaped biflagellate zoospores, so those pairs are correct.
Q37NEET 2018 · Q136
Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?
Not quite — the answer is C.
Asthma is difficulty in breathing caused by inflammation of the bronchi and bronchioles. Emphysema is a chronic disorder in which alveolar walls are damaged, so the respiratory surface decreases. The reversed pairing is the main trap.
Q38NEET 2018 · Q137
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Tricuspid valve, b. Bicuspid valve, c. Semilunar valve Column II: i. Between left atrium and left ventricle, ii. Between right ventricle and pulmonary artery, iii. Between right atrium and right ventricle
Not quite — the answer is C.
The tricuspid valve guards the opening between the right atrium and right ventricle, the bicuspid (mitral) valve lies between the left atrium and left ventricle, and a semilunar valve guards the exit from the right ventricle into the pulmonary artery. Swapping the tricuspid and bicuspid sides is the usual error.
Q39NEET 2018 · Q138
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Tidal volume, b. Inspiratory Reserve volume, c. Expiratory Reserve volume, d. Residual volume Column II: i. 2500 – 3000 mL, ii. 1100 – 1200 mL, iii. 500 – 550 mL, iv. 1000 – 1100 mL
Not quite — the answer is B.
NCERT gives tidal volume about 500 mL, inspiratory reserve volume 2500–3000 mL, expiratory reserve volume 1000–1100 mL and residual volume 1100–1200 mL. The close values of ERV and RV are the trap; residual volume is the slightly larger one.
Q40NEET 2018 · Q140
Which of the following is an amino acid derived hormone?
Not quite — the answer is C.
Epinephrine (adrenaline) is a catecholamine made from the amino acid tyrosine. Estradiol and estriol are steroid hormones made from cholesterol, and ecdysone is an insect steroid hormone.
Q41NEET 2018 · Q141
Which of the following hormones can play a significant role in osteoporosis?
Not quite — the answer is A.
Osteoporosis is loss of bone mass, common after menopause when estrogen, which protects bone, falls; parathyroid hormone raises blood calcium by bone resorption, so its excess also weakens bone. Aldosterone, progesterone and prolactin have no major role in bone mineral balance.
Q42NEET 2018 · Q142
Which of the following structures or regions is incorrectly paired with its function?
Not quite — the answer is B.
The limbic system (amygdala, hippocampus and related structures) regulates emotion, sexual behaviour and motivation, not movement; movement is coordinated by the cerebellum and motor cortex. The hypothalamus, medulla oblongata and corpus callosum are paired with their correct roles.
Q43NEET 2018 · Q143
The amnion of mammalian embryo is derived from
Not quite — the answer is C.
The amnion is formed from extra-embryonic ectoderm lined on the outside by extra-embryonic (somatic) mesoderm, i.e. the somatopleure. The yolk sac and allantois, by contrast, are formed from endoderm with splanchnic mesoderm, and the chorion includes the trophoblast.
Q44NEET 2018 · Q144
Hormones secreted by the placenta to maintain pregnancy are
Not quite — the answer is A.
NCERT lists the placental hormones as human chorionic gonadotropin, human placental lactogen, estrogens and progestogens, which together maintain pregnancy. Oxytocin is released from the posterior pituitary and prolactin from the anterior pituitary, and glucocorticoids come from the adrenal cortex.
Q45NEET 2018 · Q145
The difference between spermiogenesis and spermiation is
Not quite — the answer is D.
Spermiogenesis is the transformation of spermatids into spermatozoa, and spermiation is the release of the spermatozoa, whose heads were embedded in Sertoli cells, into the lumen of the seminiferous tubules. Spermatids themselves are formed earlier by the second meiotic division, so options that make spermatids the product of either step are wrong.
Q46NEET 2018 · Q146
The contraceptive 'SAHELI'
Not quite — the answer is C.
Saheli (centchroman) is a once-a-week non-steroidal oral pill developed by CDRI Lucknow; it acts as an anti-estrogen at the uterus and prevents implantation. It is a pill, not an IUD, it does not raise estrogen levels, and it is taken regularly rather than as an emergency post-coital pill.
Q47NEET 2018 · Q147
Ciliates differ from all other protozoans in
Not quite — the answer is D.
Ciliates such as Paramoecium have a large macronucleus and a small micronucleus, a feature unique to them among protozoans. Contractile vacuoles also occur in freshwater amoebae and flagellates, pseudopodia belong to amoeboid protozoans and flagella to flagellates.
Q48NEET 2018 · Q148
Identify the vertebrate group of animals characterized by crop and gizzard in its digestive system.
Not quite — the answer is A.
Birds have a crop to store food and a muscular gizzard to grind it, since they have no teeth; NCERT lists these as additional chambers of the bird digestive tract. Reptiles, amphibians and bony fishes do not have this crop-and-gizzard arrangement.
Q49NEET 2018 · Q150
Which one of these animals is not a homeotherm?
Not quite — the answer is B.
Chelone is a turtle, a reptile, so it is poikilothermic (cold-blooded). Camelus (camel) and Macropus (kangaroo) are mammals and Psittacula (parrot) is a bird, all of which are homeotherms.
Q50NEET 2018 · Q151
Which of the following animals does not undergo metamorphosis?
Not quite — the answer is C.
Earthworm shows direct development: young worms hatch from cocoons with no larval stage, so there is no metamorphosis. Moths pass through caterpillar and pupa, tunicates have a tadpole larva that undergoes retrogressive metamorphosis, and starfish have a bilateral larva that becomes the radial adult.
Q51NEET 2018 · Q152
Which of the following organisms are known as chief producers in the oceans?
Not quite — the answer is B.
NCERT describes diatoms as the chief producers in the oceans. Dinoflagellates are mostly marine photosynthetic protists too, and cyanobacteria are important producers, but the textbook title of chief producers belongs to diatoms; euglenoids are mostly freshwater.
Q52NEET 2018 · Q154
All of the following are included in 'Ex-situ conservation' except
Not quite — the answer is B.
Sacred groves are tracts of natural forest protected by local communities, so species are conserved in their own habitat; this is in-situ conservation. Botanical gardens, wildlife safari parks and seed banks keep organisms or germplasm away from their natural habitat and are ex-situ methods.
Q53NEET 2018 · Q156
In a growing population of a country,
Not quite — the answer is C.
A growing (expanding) population has a broad-based, triangular age pyramid, meaning pre-reproductive individuals outnumber reproductive ones. Roughly equal numbers give a bell-shaped, stable pyramid, and fewer pre-reproductive individuals give an urn-shaped, declining one.
Q54NEET 2018 · Q157
Which part of poppy plant is used to obtain the drug "Smack"?
Not quite — the answer is B.
Smack (heroin, diacetylmorphine) is made by acetylation of morphine, which is extracted from the latex of the unripe capsules of the poppy Papaver somniferum. Roots, flowers and leaves are not the source.
Q55NEET 2018 · Q158
All of the following are part of an operon except
Not quite — the answer is A.
An operon such as the lac operon consists of a promoter, an operator and structural genes (with a regulator gene nearby). Enhancers are regulatory DNA sequences of eukaryotic genes that can act from a distance and are not parts of prokaryotic operons.
Q56NEET 2018 · Q159
A woman has an X-linked condition on one of her X chromosomes. This chromosome can be inherited by
Not quite — the answer is D.
A mother passes one of her two X chromosomes to every child, sons and daughters alike, so either sex can receive the affected X. It is the father's X that goes only to daughters, which is the trap.
Q57NEET 2018 · Q160
According to Hugo de Vries, the mechanism of evolution is
Not quite — the answer is B.
From his work on evening primrose, de Vries proposed that new species arise by large, sudden mutations producing single-step jumps, which he called saltation. Darwin, in contrast, stressed small continuous variations, so minor or multiple-step changes describe Darwinian ideas, not de Vries.
Q58NEET 2018 · Q161
AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA?
Not quite — the answer is C.
The mRNA has the same sequence and polarity as the coding strand, except that uracil replaces thymine, so AGGTATCGCAT becomes AGGUAUCGCAU. The complementary sequence UCCAUAGCGUA would be obtained by copying the coding strand itself, which is the trap.
Q59NEET 2018 · Q162
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Proliferative Phase, b. Secretory Phase, c. Menstruation Column II: i. Breakdown of endometrial lining, ii. Follicular Phase, iii. Luteal Phase
Not quite — the answer is A.
The proliferative phase of the uterus, when the endometrium regenerates, coincides with the follicular phase of the ovary; the secretory phase coincides with the luteal phase, when the corpus luteum secretes progesterone; and menstruation is the breakdown of the endometrial lining.
Q60NEET 2018 · Q163
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Glycosuria, b. Gout, c. Renal calculi, d. Glomerular nephritis Column II: i. Accumulation of uric acid in joints, ii. Mass of crystallised salts within the kidney, iii. Inflammation in glomeruli, iv. Presence of glucose in urine
Not quite — the answer is D.
Glycosuria is glucose in the urine, gout is accumulation of uric acid crystals in joints, renal calculi are masses of crystallised salts in the kidney, and glomerulonephritis is inflammation of the glomeruli.
Q61NEET 2018 · Q164
Match the items given in Column I with those in Column II and select the correct option given below: Column I (Function): a. Ultrafiltration, b. Concentration of urine, c. Transport of urine, d. Storage of urine Column II (Part of Excretory System): i. Henle's loop, ii. Ureter, iii. Urinary bladder, iv. Malpighian corpuscle, v. Proximal convoluted tubule
Not quite — the answer is B.
Ultrafiltration happens in the Malpighian corpuscle (glomerulus with Bowman's capsule); the loop of Henle sets up the counter-current gradient that concentrates urine; the ureter carries urine; and the urinary bladder stores it. The proximal convoluted tubule mainly reabsorbs and is the distractor.
Q62NEET 2018 · Q166
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Fibrinogen, b. Globulin, c. Albumin Column II: i. Osmotic balance, ii. Blood clotting, iii. Defence mechanism
Not quite — the answer is D.
Fibrinogen is converted to fibrin during blood clotting, globulins (including antibodies) are mainly involved in the defence mechanisms of the body, and albumin maintains the osmotic balance of blood.
Q63NEET 2018 · Q168
Calcium is important in skeletal muscle contraction because it
Not quite — the answer is C.
Ca²⁺ released from the sarcoplasmic reticulum binds to troponin C, which moves tropomyosin and unmasks the myosin-binding active sites on actin so that cross bridges can form. Calcium does not bind myosin ATPase directly, and detachment of the myosin head requires a fresh ATP, not calcium.
Q64NEET 2018 · Q169
Nissl bodies are mainly composed of
Not quite — the answer is D.
Nissl granules in the cell body and dendrites of neurons are clusters of rough endoplasmic reticulum with attached and free ribosomes, reflecting active protein synthesis. They do not contain smooth ER or DNA.
Q65NEET 2018 · Q170
Which of these statements is incorrect?
Not quite — the answer is D.
Oxidative phosphorylation is carried out by the electron transport chain and ATP synthase located in the inner mitochondrial membrane, not the outer membrane. The other statements are correct: glycolysis is cytosolic and needs a supply of NAD⁺, and TCA enzymes lie in the matrix (succinate dehydrogenase being bound to the inner membrane).
Q66NEET 2018 · Q171
Select the incorrect match:
Not quite — the answer is D.
Polytene chromosomes occur in the salivary glands of insect larvae such as Drosophila; the giant chromosomes of amphibian oocytes are lampbrush chromosomes, which are diplotene bivalents. Submetacentric chromosomes look L-shaped and allosomes are the sex chromosomes, so those matches are correct.
Q67NEET 2018 · Q174
Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as
Not quite — the answer is C.
Several ribosomes translating the same mRNA together form a polysome (polyribosome), which makes many copies of the polypeptide at once. A nucleosome is a unit of DNA wound on a histone octamer, and a plastidome is the total plastid content of a cell.
Q68NEET 2018 · Q175
In which disease does mosquito transmitted pathogen cause chronic inflammation of lymphatic vessels?
Not quite — the answer is C.
Filariasis (elephantiasis) is caused by Wuchereria bancrofti, transmitted by the bite of female Culex mosquitoes; the worms live in lymphatic vessels and cause chronic inflammation and swelling of the limbs and genital organs. Ringworm is a fungal skin infection, and ascariasis and amoebiasis spread through contaminated food and water.
Q69NEET 2018 · Q176
Which of the following is not an autoimmune disease?
Not quite — the answer is A.
Alzheimer's disease is a neurodegenerative disorder linked to loss of cholinergic neurons and amyloid plaques, not an attack by the immune system on self tissue. Rheumatoid arthritis, psoriasis and vitiligo are autoimmune disorders.
Q70NEET 2018 · Q177
Among the following sets of examples for divergent evolution, select the incorrect option:
Not quite — the answer is D.
The eyes of octopus (a mollusc) and of mammals have similar function but different origin, so they are analogous organs produced by convergent evolution. The brain, heart and forelimbs of bat, man and cheetah share a common mammalian origin and are homologous, showing divergent evolution.
Q71NEET 2018 · Q178
Conversion of milk to curd improves its nutritional value by increasing the amount of
Not quite — the answer is A.
Lactic acid bacteria such as Lactobacillus that turn milk into curd also increase its vitamin B₁₂ content, which NCERT notes as the nutritional improvement. They do not synthesise the fat-soluble vitamins A, D or E.
Q72NEET 2018 · Q179
The similarity of bone structure in the forelimbs of many vertebrates is an example of
Not quite — the answer is C.
Forelimbs of whales, bats, cheetahs and humans have the same basic pattern of bones (humerus, radius-ulna, carpals, metacarpals, phalanges) though they do different jobs, which shows common ancestry: these are homologous organs. Analogy and convergent evolution refer to similar function with different structure and origin.
Q73NEET 2018 · Q180
Which of the following characteristics represent 'Inheritance of blood groups' in humans? a. Dominance b. Co-dominance c. Multiple allele d. Incomplete dominance e. Polygenic inheritance
Not quite — the answer is B.
ABO blood groups are controlled by one gene I with three alleles (multiple alleles); Iᴬ and Iᴮ are each dominant over i (dominance), and when together both are expressed (co-dominance). Blood group is not a polygenic trait and shows no incomplete dominance.
Biology: not in the current NEET syllabus
These 13 questions are from topics NCERT dropped in its 2023 revision. Shown for completeness; you can skip them for NEET 2027.
13 questions. Tap an option to check your answer.
Q1NEET 2018 · Q95
Which of the following elements is responsible for maintaining turgor in cells?
Not quite — the answer is A.
Potassium is the main cation that maintains cell turgor and anion-cation balance, and its movement into guard cells drives stomatal opening. Sodium is not an essential macronutrient for most plants, magnesium is part of chlorophyll and calcium is used in the middle lamella.
Q2NEET 2018 · Q107
Which of the following flowers only once in its life-time?
Not quite — the answer is C.
Bamboo species are monocarpic: they grow vegetatively for 50 to 100 years, flower once, produce seeds and die. Mango, jackfruit and papaya are polycarpic perennials that flower every season.
Q3NEET 2018 · Q108
Offsets are produced by
Not quite — the answer is B.
An offset is a vegetative propagule (as in Eichhornia or Pistia), so it arises by mitotic divisions and its cells are genetically identical to the parent. Meiosis forms gametes, and parthenocarpy and parthenogenesis concern fruit or embryo development without fertilisation.
Q4NEET 2018 · Q112
World Ozone Day is celebrated on
Not quite — the answer is A.
World Ozone Day (International Day for the Preservation of the Ozone Layer) is observed on 16 September, the date of signing of the Montreal Protocol in 1987. 5 June is World Environment Day and 22 April is Earth Day.
Q5NEET 2018 · Q113
Which of the following is a secondary pollutant?
Not quite — the answer is D.
Ground-level ozone is not emitted directly; it forms in the air when nitrogen oxides and hydrocarbons react in sunlight (photochemical smog), so it is a secondary pollutant. SO₂, CO₂ and CO are released directly from combustion and are primary pollutants.
Q6NEET 2018 · Q116
In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen?
Not quite — the answer is B.
UV radiation breaks CFCs in the stratosphere to release chlorine atoms, which break O₃ into O₂ and are regenerated, so each Cl atom acts as a catalyst and destroys many ozone molecules. Iron and carbon do not act this way, and oxygen is a product, not the catalyst.
Q7NEET 2018 · Q122
Stomatal movement is not affected by
Not quite — the answer is A.
Stomatal opening and closing respond to light, temperature, CO₂ concentration and water status (through abscisic acid and the turgor of guard cells). Oxygen concentration has no significant effect on stomatal movement.
Q8NEET 2018 · Q133
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Herbarium, b. Key, c. Museum, d. Catalogue Column II: i. It is a place having a collection of preserved plants and animals. ii. A list that enumerates methodically all the species found in an area with brief description aiding identification. iii. Is a place where dried and pressed plant specimens mounted on sheets are kept. iv. A booklet containing a list of characters and their alternates which are helpful in identification of various taxa.
Not quite — the answer is D.
A herbarium stores dried, pressed plant specimens on sheets; a key lists contrasting characters (couplets) used to identify taxa; a museum holds preserved plants and animals; and a catalogue is a methodical list of species of an area with brief descriptions. The trap is swapping key and catalogue, since both are written aids.
Q9NEET 2018 · Q139
The transparent lens in the human eye is held in its place by
Not quite — the answer is C.
The lens is held by suspensory ligaments (zonules) attached to the ciliary body. The ciliary body contains smooth muscle that changes lens curvature, but the lens itself hangs from ligaments; the iris only controls the pupil size.
Q10NEET 2018 · Q149
Which of the following features is used to identify a male cockroach from a female cockroach?
Not quite — the answer is B.
Only male cockroaches have a pair of short, thread-like anal (caudal) styles on the 9th abdominal sternum. Anal cerci are present in both sexes, both have tegmina, and the boat-shaped sternum belongs to the 7th segment of the female.
Q11NEET 2018 · Q155
Match the items given in Column I with those in Column II and select the correct option given below: Column I: a. Eutrophication, b. Sanitary landfill, c. Snow blindness, d. Jhum cultivation Column II: i. UV-B radiation, ii. Deforestation, iii. Nutrient enrichment, iv. Waste disposal
Not quite — the answer is A.
Eutrophication is the nutrient enrichment of water bodies, a sanitary landfill is a method of solid waste disposal, snow blindness is inflammation of the cornea caused by high UV-B, and slash-and-burn jhum cultivation causes deforestation.
Q12NEET 2018 · Q165
Which of the following gastric cells indirectly help in erythropoiesis?
Not quite — the answer is D.
Parietal (oxyntic) cells secrete HCl and Castle's intrinsic factor, which is needed to absorb vitamin B₁₂; B₁₂ is required for the maturation of red blood cells, so these cells help erythropoiesis indirectly. Chief cells secrete pepsinogen and goblet or mucous cells secrete mucus.
Q13NEET 2018 · Q172
Which of the following terms describe human dentition?
Not quite — the answer is B.
Human teeth sit in sockets of the jaw bones (thecodont), appear in two sets, milk and permanent (diphyodont), and are of different types, incisors, canines, premolars and molars (heterodont). Pleurodont teeth attached to the side of the jaw and homodont teeth of one type are found in some lower vertebrates.
Chapter-wise split of NEET 2018 Biology
- Molecular Basis of Inheritance5 Q
- Biological Classification5 Q
- Sexual Reproduction in Flowering Plants4 Q
- Biotechnology and Its Applications4 Q
- Principles of Inheritance and Variation4 Q
- Cell: The Unit of Life4 Q
- Anatomy of Flowering Plants4 Q
- Human Reproduction4 Q
- Organisms and Populations3 Q
- Plant Kingdom3 Q
- Animal Kingdom3 Q
- Human Health and Disease3 Q
- Evolution3 Q
- Photosynthesis in Higher Plants2 Q
- Respiration in Plants2 Q
- Morphology of Flowering Plants2 Q
- Breathing and Exchange of Gases2 Q
- Body Fluids and Circulation2 Q
- Locomotion and Movement2 Q
- Neural Control and Coordination2 Q
- Excretory Products and Their Elimination2 Q
- Biotechnology: Principles and Processes1 Q
- Ecosystem1 Q
- Biomolecules1 Q
- Cell Cycle and Cell Division1 Q
- Chemical Coordination and Integration1 Q
- Reproductive Health1 Q
- Biodiversity and Conservation1 Q
- Microbes in Human Welfare1 Q
About this paper
How many questions from NEET 2018 are on this page?
162 questions (Physics 36, Chemistry 40, Biology 86). 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 NEET 2018 paper, conducted by CBSE. The answer to every question was checked by the RankUp team, and the explanations are RankUp's own.
Is NEET 2018 useful for NEET 2027?
Yes. The NEET syllabus is built on the same NCERT books. 20 questions here are on topics NCERT has since dropped; they are listed separately so you can skip them.
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