Question 1 (B1.1)
What is not a characteristic of all living organisms?
A. excretion
B. growth
C. photosynthesis
D. sensitivity
▶️Answer/Explanation
Answer: C. photosynthesis
Explanation: While excretion, growth, and sensitivity are characteristics of all living organisms, photosynthesis is specific to plants, algae, and some bacteria. Animals and fungi do not perform photosynthesis. The seven characteristics of living organisms are movement, respiration, sensitivity, growth, reproduction, excretion, and nutrition (MRS GREN).
Question 2 (B2.1)
The diagrams show four different cells found in living organisms.
Which cell types have a large surface area for diffusion?
A. 1 and 2
B. 1 and 4
C. 2 and 3
D. 3 and 4
▶️Answer/Explanation
Answer: B. 1 and 4
Explanation: Cells specialized for diffusion typically have adaptations to increase their surface area. In the human body, root hair cells (1) and villi cells (4) are examples of cells with large surface areas for absorption and diffusion. Root hair cells have long extensions, while villi cells have microvilli that greatly increase the surface area for nutrient absorption in the small intestine.
Question 3 (B4.1)
What colour does Benedict’s solution change to when heated with a reducing sugar?
A. blue
B. blue-black
C. orange
D. purple
▶️Answer/Explanation
Answer: C. orange
Explanation: Benedict’s solution is used to test for reducing sugars. It starts blue (copper sulfate in alkaline solution) and changes color in the presence of reducing sugars: green → yellow → orange → brick-red precipitate, depending on the concentration of reducing sugar present. A positive result is typically considered to be orange or red, indicating the presence of reducing sugars like glucose or fructose.
Question 4 (B5.1)
A mixture of starch and saliva was set up at four different temperatures. Each mixture was tested with iodine solution after 15 minutes and again after 30 minutes. The results are shown in the table:
| temperature /°C | colour with iodine solution (15 minutes) | colour with iodine solution (30 minutes) |
|---|---|---|
| 0 | blue-black | blue-black |
| 15 | blue-black | brown |
| 35 | brown | brown |
| 95 | blue-black | blue-black |
What do the results suggest?
A. The enzyme in saliva is inactive at 95°C.
B. The enzyme in saliva is slow to work at 35°C.
C. The enzyme in saliva works equally well at 15°C and 35°C.
D. The enzyme in saliva works faster at higher temperatures.
▶️Answer/Explanation
Answer: A. The enzyme in saliva is inactive at 95°C.
Explanation: The enzyme in saliva (amylase) breaks down starch into simpler sugars. Iodine turns blue-black in the presence of starch and remains brown when starch is absent. At 95°C, the enzyme is denatured (permanently damaged), so it cannot break down starch, hence the persistent blue-black color. At 35°C (body temperature), the enzyme works optimally, quickly breaking down starch (brown at both times). At 15°C, the enzyme works slowly (blue-black at 15 minutes but brown by 30 minutes).
Question 5 (B6.1)
What is the effect of nitrate ion deficiency on plants?
| leaf colour | growth | |
|---|---|---|
| A | green | good |
| B | green | poor |
| C | yellow | good |
| D | yellow | poor |
▶️Answer/Explanation
Answer: D. yellow, poor
Explanation: Nitrate ions are essential for plant growth as they are needed to make amino acids and proteins. A deficiency causes chlorosis (yellowing of leaves) because nitrate is needed to make chlorophyll. It also results in stunted growth because proteins are needed for cell growth and division. The yellow color appears first in older leaves as the plant moves the limited nitrates to newer growth.
Question 6 (B7.2)
Much of the internal surface of the human small intestine is covered with villi. What is the function of villi?
A. excretion of waste into the intestine
B. secretion of enzymes into the intestine
C. to improve blood circulation in the intestine walls
D. to increase the internal surface area of the intestine
▶️Answer/Explanation
Answer: D. to increase the internal surface area of the intestine
Explanation: Villi are finger-like projections in the small intestine that greatly increase the surface area for absorption of digested food molecules. Each villus contains a lacteal (lymph vessel) and blood capillaries to absorb nutrients. The large surface area allows for more efficient absorption of nutrients into the bloodstream. While some enzymes are secreted between villi, this is not their primary function.
Question 7 (B8.3)
Under which conditions will transpiration from a plant be fastest?
| temperature | humidity | |
|---|---|---|
| A | high | high |
| B | high | low |
| C | low | high |
| D | low | low |
▶️Answer/Explanation
Answer: B. high, low
Explanation: Transpiration (water loss from leaves) is fastest when: (1) temperature is high (increases evaporation), (2) humidity is low (greater concentration gradient between leaf and air), (3) wind speed is high (removes water vapor near leaf), and (4) light intensity is high (stomata open for photosynthesis). High humidity reduces the water potential gradient, slowing transpiration, while low temperatures reduce the kinetic energy of water molecules.
Question 8 (B11.1)
A student breathed gently in and out of the mouth piece of the apparatus shown.
What were the results after 10 breaths?
| P | Q | |
|---|---|---|
| A | clear | clear |
| B | clear | milky |
| C | milky | clear |
| D | milky | milky |
▶️Answer/Explanation
Answer: D. milky, milky
Explanation: The apparatus tests for carbon dioxide in exhaled air. Limewater turns milky in the presence of CO₂. When breathing out, air passes through both tubes, so both would turn milky as exhaled air contains about 4% CO₂. The first tube (P) would turn milky first as it encounters the exhaled air first, but after 10 breaths, both would show the milky precipitate of calcium carbonate formed when CO₂ reacts with limewater (Ca(OH)₂ + CO₂ → CaCO₃ + H₂O).
Question 9 (B13.1)
During an experiment, auxin is applied to one side of a shoot just behind the tip. What will this stimulate?
A. decreased cell elongation in all cells
B. decreased cell elongation on the side with extra auxin
C. increased cell elongation in all cells
D. increased cell elongation on the side with extra auxin
▶️Answer/Explanation
Answer: B
Question 10 (B15.4)
In human reproduction, which cells are haploid?
| gametes | zygotes | |
|---|---|---|
| A | ✓ | ✓ |
| B | ✓ | ✗ |
| C | ✗ | ✓ |
| D | ✗ | ✗ |
▶️Answer/Explanation
Answer: B. ✓, ✗
Explanation: Gametes (sperm and egg cells) are haploid (n) containing half the normal chromosome number, while zygotes are diploid (2n) formed by the fusion of two haploid gametes. Human body cells are diploid with 46 chromosomes, while gametes have 23 chromosomes. During fertilization, the haploid sperm (23) fuses with the haploid egg (23) to form a diploid zygote (46).
Question 11 (B16.3)
The pedigree diagram shows the inheritance of a recessive condition.
Which statements are correct with reference to this condition?
1. P and Q are both heterozygous for the condition.
2. Q and R have different genotypes.
3. P and R have the same genotype.
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
▶️Answer/Explanation
Answer: A. 1 and 2 only
Explanation: For a recessive condition to appear, an individual must inherit two recessive alleles (aa). Unaffected parents (P and Q) who have an affected child (R) must both be heterozygous carriers (Aa). Q is affected (aa) and R is unaffected, so they have different genotypes (aa vs Aa or AA). P and R could have the same genotype (both Aa) but R could also be AA, so statement 3 isn’t necessarily correct.
Question 12 (B18.1)
What is the name given to a unit containing all of the organisms and their environment interacting together in a given area?
A) ecosystem
B) food chain
C) food web
D) trophic level
▶️Answer/Explanation
Answer: D
Question 13 (C10.2)
Which row about some of the stages of eutrophication is correct?
| growth of producers | growth of decomposers | respiration of decomposers | concentration of dissolved oxygen | |
|---|---|---|---|---|
| A | decreases | increases | decreases | increases |
| B | decreases | decreases | increases | increases |
| C | increases | decreases | decreases | decreases |
| D | increases | increases | increases | decreases |
▶️Answer/Explanation
Answer: D) increases, increases, increases, decreases
Explanation: Eutrophication occurs when excess nutrients (like nitrates and phosphates) enter a water body, leading to increased growth of producers (algae/plants). When these producers die, decomposers multiply and respire, consuming dissolved oxygen, which decreases oxygen levels in the water.
Question 14 (C12.4)
A mixture of solid sulfur and solid sodium chloride is added to water and stirred. Sulfur is insoluble in water. Sodium chloride is soluble in water. Which processes are used to obtain pure sodium chloride from the mixture?
A) distillation then chromatography
B) distillation then crystallisation
C) filtration then chromatography
D) filtration then crystallisation
▶️Answer/Explanation
Answer: B
Question 15 (C3.3)
Which sample contains the most molecules?
A) 16 dm³ CH₄
B) 28 dm³ C₂H₄
C) 16 g CH₄
D) 28 g C₂H₄
▶️Answer/Explanation
Answer: B) 28 dm³ C₂H₄
Explanation: At room temperature and pressure, 1 mole of any gas occupies 24 dm³. Therefore, 28 dm³ of C₂H₄ is more than 1 mole (28/24 ≈ 1.17 moles), while 16 dm³ of CH₄ is less than 1 mole (16/24 ≈ 0.67 moles). For the masses: 16 g CH₄ is 1 mole (CH₄ molar mass = 16 g/mol), and 28 g C₂H₄ is also 1 mole (C₂H₄ molar mass = 28 g/mol). Thus, 28 dm³ C₂H₄ has the most molecules.
Question 16 (C4.1)
Which row describes what happens at the electrodes during electrolysis?
| at the anode | at the cathode | |
|---|---|---|
| A | negative ions gain electrons | positive ions lose electrons |
| B | negative ions lose electrons | positive ions gain electrons |
| C | positive ions gain electrons | negative ions lose electrons |
| D | positive ions lose electrons | negative ions gain electrons |
▶️Answer/Explanation
Answer: B) negative ions lose electrons, positive ions gain electrons
Explanation: During electrolysis, oxidation occurs at the anode (negative ions lose electrons), and reduction occurs at the cathode (positive ions gain electrons). This is summarized by the mnemonic “OIL RIG” (Oxidation Is Loss, Reduction Is Gain).
Question 17 (C5.1)
Which process is exothermic?
A boiling water
B cracking a long chain alkene
C decomposition of limestone
D identification of hydrogen using a lit splint
▶️Answer/Explanation
Answer: D
Explanation: An exothermic reaction releases heat energy to the surroundings. The identification of hydrogen using a lit splint is exothermic because it involves combustion (a “pop” sound), which releases heat. Boiling water (A) requires heat input (endothermic). Cracking alkenes (B) and decomposing limestone (C) both require heat energy input, making them endothermic processes.
Question 18 (C6.2)
Magnesium ribbon is reacted with excess dilute hydrochloric acid at 25°C. The experiment is repeated at 45°C, using the same mass of magnesium and the same volume and concentration of dilute hydrochloric acid.
Which statement explains why the reaction is faster at 45°C?
A Collisions between particles at 45°C are less frequent and fewer colliding particles possess the activation energy.
B Collisions between particles at 45°C are less frequent and more colliding particles possess the activation energy.
C Collisions between particles at 45°C are more frequent and fewer colliding particles possess the activation energy.
D Collisions between particles at 45°C are more frequent and more colliding particles possess the activation energy.
▶️Answer/Explanation
Answer: D
Explanation: Increasing temperature increases the kinetic energy of particles, making them move faster. This results in: 1. More frequent collisions (higher collision frequency) 2. More particles having energy ≥ activation energy Both factors contribute to increased reaction rate. Options A-C all contain at least one incorrect statement about either collision frequency or activation energy.
Question 19 (C6.3)
Which word equation represents a redox reaction?
A carbon + copper oxide → copper + carbon dioxide
B hydrochloric acid + potassium hydroxide → potassium chloride + water
C magnesium carbonate → magnesium oxide + carbon dioxide
D sodium sulfate + barium nitrate → barium sulfate + sodium nitrate
▶️Answer/Explanation
Answer: A
Explanation: A redox reaction involves both oxidation and reduction. In option A: – Carbon is oxidized (gains oxygen to form CO₂) – Copper is reduced (loses oxygen) The other options show: B – Neutralization (acid-base) C – Thermal decomposition D – Precipitation (double displacement) None of these are redox reactions.
Question 20 (C7.1)
Salts are made by reacting dilute hydrochloric acid with four substances. Which substances produce a gas when reacted with dilute hydrochloric acid?
1 magnesium
2 magnesium carbonate
3 magnesium hydroxide
4 magnesium oxide
A 1 and 2
B 1 and 3
C 2 and 4
D 3 and 4
▶️Answer/Explanation
Answer: A
Explanation: – Magnesium (1) reacts with HCl to produce hydrogen gas: Mg + 2HCl → MgCl₂ + H₂ – Magnesium carbonate (2) reacts with HCl to produce CO₂ gas: MgCO₃ + 2HCl → MgCl₂ + H₂O + CO₂ Magnesium hydroxide (3) and oxide (4) react with HCl but only produce salt and water (no gas): Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O MgO + 2HCl → MgCl₂ + H₂O
Question 21 (C8.1)
Which statement about elements in the Periodic Table is correct?
A The density of the elements in Group I increases up the group.
B The metallic character of the elements increases across a period from left to right.
C The number of protons in the atoms of the elements increases across a period from left to right.
D The reactivity of the elements in Group I decreases down the group.
▶️Answer/Explanation
Answer: C
Explanation: A – Incorrect: Group I density increases DOWN the group (opposite of stated) B – Incorrect: Metallic character DECREASES across a period left to right C – Correct: Proton number (atomic number) always increases left to right in periods D – Incorrect: Group I reactivity INCREASES down the group The number of protons defines the element and always increases across a period.
Question 22 (C9.4)
Four metals W, X, Y and Z are added to aqueous solutions of their ions.
The results are shown.
What is the order of reactivity?
▶️Answer/Explanation
Answer: D
Explanation: A more reactive metal can displace a less reactive metal from its compound. From the table: – Z doesn’t react with any ions → least reactive – Y only reacts with Z ions → more reactive than Z – X reacts with Y and Z ions → more reactive than Y – W reacts with X, Y and Z ions → most reactive Thus the order is Z (least) → Y → X → W (most).
Question 23 (C10.2)
Which process does not produce carbon dioxide?
A acid reacting with a metal
B acid reacting with sodium carbonate
C complete combustion of methane
D respiration
▶️Answer/Explanation
Answer: A
Explanation: Acid + metal produces hydrogen gas (H₂), not CO₂. The other options all produce CO₂: B – Acid + carbonate: 2HCl + Na₂CO₃ → 2NaCl + H₂O + CO₂ C – Combustion: CH₄ + 2O₂ → CO₂ + 2H₂O D – Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O Acid + metal: Mg + 2HCl → MgCl₂ + H₂
Question 24 (C5.1)
The Haber process is used to make ammonia. Which row shows the conditions used in this process?
▶️Answer/Explanation
Answer: B
Explanation: The Haber process uses: – Catalyst: Iron (Fe) with promoters – Temperature: 450°C (compromise between rate and yield) – Pressure: 200-250 atm (high pressure favors product side) V₂O₅ is used in the Contact process (sulfuric acid production), not the Haber process.
Question 25 (C11.3)
The Contact process is used to manufacture sulfuric acid.
Which statement about the Contact process is not correct?
A A nickel catalyst is used.
B Sulfur dioxide reacts with oxygen to form sulfur trioxide.
C Sulfur burns to form sulfur dioxide.
D Sulfur trioxide dissolves in concentrated sulfuric acid to form oleum.
▶️Answer/Explanation
Answer: A
Explanation: The Contact process uses vanadium(V) oxide (V₂O₅) as catalyst, not nickel. All other statements are correct: B – 2SO₂ + O₂ ⇌ 2SO₃ (main reaction) C – S + O₂ → SO₂ (initial step) D – SO₃ + H₂SO₄ → H₂S₂O₇ (oleum) Nickel is used in hydrogenation reactions, not the Contact process.
Question 26 (C11.5)
What reacts with ethene to make ethanol?
A bromine
B hydrogen
C steam
D yeast
▶️Answer/Explanation
Answer: C
Explanation: Ethanol is produced from ethene by hydration with steam: C₂H₄ + H₂O → C₂H₅OH (with acid catalyst) Bromine (A) would cause addition to form dibromoethane. Hydrogen (B) would form ethane. Yeast (D) ferments sugars to ethanol but doesn’t react with ethene.
Question 27 (C11.7)
Poly(ethene) is made from ethene by the process of addition polymerisation. Which word describes ethene in this process?
A fuel
B catalyst
C monomer
D solvent
▶️Answer/Explanation
Answer: C
Explanation: In polymerization, the small repeating units (ethene in this case) are called monomers. Many monomers join to form the polymer (polyethene). It’s not a fuel (A), catalyst (B speeds reaction but isn’t consumed), or solvent (D dissolves other substances).
Question 28 (P1.7)
A concrete block exerts a pressure on the ground. Which expression is used to calculate the pressure due to the block?
A (mass of block) × (area of contact with the ground)
B \( \frac{(mass of block)}{ (area of contact with the ground)}\)
C (weight of block) × (area of contact with the ground)
D \( \frac{(weight of block)}{ (area of contact with the ground)}\)
▶️Answer/Explanation
Answer: D
Explanation: Pressure = Force/Area. For objects on Earth, the force is weight (mass × gravity), so: Pressure = Weight/Area Mass alone (A,B) is incorrect because it doesn’t account for gravity. Multiplying weight by area (C) would give wrong units (N×m² instead of N/m²).
Question 29 (P1.5.2)
The diagrams show four uniform beams, each supported by a pivot at its centre. Which diagram shows a beam that is balanced?
▶️Answer/Explanation
Answer: A
Explanation: For balance, clockwise moment = anticlockwise moment (F₁d₁ = F₂d₂). In diagram A: Left side: 2.0N × 1.0m = 2.0Nm Right side: 4.0N × 0.5m = 2.0Nm Moments are equal → balanced Other options have unequal moments (B: 2≠1, C: 2≠2.5, D: 1.5≠2)
Question 30 (P1.6.2)
The diagram shows a box of weight 600 N being pulled up a frictionless slope by a force.
How much work is done against gravity in moving the box from X to Y?
A 600 J
B 1800 J
C 24000 J
D 30000 J
▶️Answer/Explanation
Answer: B
Explanation: Work done against gravity = weight × vertical height W = mgh = 600N × 3m = 1800J The horizontal distance (4m) and slope length (5m) are irrelevant for work against gravity. Only the vertical displacement (3m) matters when calculating work done against gravity.
Question 31 (P1.6.3
Electricity is generated in power stations. Many power stations use steam to drive turbines. Which type of power station does not use steam?
A chemical energy (fuel) power stations
B geothermal energy power stations
C hydroelectric energy power stations
D nuclear energy power stations
▶️Answer/Explanation
Answer: C
Explanation: Hydroelectric stations use falling water to directly drive turbines, without steam generation. All other options involve heating water to produce steam: A – Fossil fuels heat water B – Geothermal heat produces steam D – Nuclear reactions heat water Hydroelectric is the only option where mechanical energy comes directly from water flow, not steam.
Question 32 (P3.3)
Which part of the electromagnetic spectrum is often involved in thermal energy transfer by radiation?
A infrared
B radio
C ultraviolet
D X-rays
▶️Answer/Explanation
Answer: A
Explanation: Infrared radiation is primarily responsible for thermal energy transfer by radiation. Objects at everyday temperatures emit mostly infrared. While all EM waves can transfer energy, infrared is most associated with heat transfer. UV (C) and X-rays (D) have higher energy but aren’t the main thermal radiation. Radio waves (B) have much lower energy.
Question 33 (Sub-topic: P3.1)
The diagram shows the direction of a wave that passes a particle. The particle is made to vibrate by the wave. The direction of vibration of the particle is shown.
Which row states the type of wave that passes the particle, and gives an example of this type of wave?
▶️Answer/Explanation
Answer: C
Explanation: Light is an example of a transverse wave, where the direction of vibration of the particles is perpendicular to the direction of wave propagation. Sound, on the other hand, is a longitudinal wave, where the vibration is parallel to the direction of wave propagation.
Question 34 (P3.2.2)
The diagram shows a ray of light travelling in glass from point P. Angle x is greater than the critical angle.
In which labelled direction does the ray continue?
▶️Answer/Explanation
Answer: D
Explanation: When angle of incidence > critical angle, total internal reflection occurs. The light reflects back into the glass (path D) rather than refracting out (A,B) or along the surface (C). This principle is used in optical fibers where light is kept inside by total internal reflection.
Question 35 (P4.1)
In an experiment to investigate induced magnetism, a magnet is brought close to samples of different unmagnetised materials. A student records the results using diagrams.
The teacher checks the diagrams and finds that only one result is correctly recorded.
Which result is correctly recorded?
▶️Answer/Explanation
Answer: B
Question 36 (P4.2.2)
The current in an ammeter is 1.5 A. How much charge passes through the ammeter in one minute?
A 0.025 C
B 1.5 C
C 40 C
D 90 C
▶️Answer/Explanation
Answer: D
Explanation: Charge (Q) = Current (I) × Time (t) Q = 1.5A × 60s = 90C Remember to convert minutes to seconds (1 minute = 60s). The other options either forget this conversion (B: 1.5×1=1.5) or miscalculate (A: 1.5/60, C: 60/1.5).
Question 37 (P4.2.5)
A heating element in an electric kettle has a resistance of 24 Ω. When the kettle is connected to a 240 V supply, it takes 2.5 minutes to boil some water. How much energy is used to boil the water?
A 16 J
B 960 J
C 6000 J
D 360000 J
▶️Answer/Explanation
Answer: D
Explanation: Energy = Power × Time Power = V²/R = (240)²/24 = 2400W Time = 2.5min = 150s Energy = 2400W × 150s = 360,000J Option C forgets to square voltage (240/24×150=1500). Option B calculates current first (I=V/R=10A) then P=I²R=2400W but uses wrong time (0.4s). Option A is V/I.
Question 38 (P4.4)
Fuses are used in domestic electric circuits. Which statement about fuses is correct?
A A fuse is connected in the live wire.
B A fuse is connected in the neutral wire.
C A 3 A fuse produces a current of exactly 3 A in the circuit.
D A 3 A fuse produces a minimum current of 3 A in the circuit.
▶️Answer/Explanation
Answer: A
Explanation: Fuses must be in the live wire to disconnect the circuit if excess current flows. They don’t “produce” current (C,D incorrect) – they melt when current exceeds their rating. The neutral wire (B) shouldn’t have a fuse as it would leave appliances live if blown. A 3A fuse melts when current exceeds ~3A, not producing or maintaining any specific current.
Question 39 (Sub-topic: P4.5.3)
A solenoid carrying a current produces a magnetic field. Which diagram shows the magnetic field pattern?
▶️Answer/Explanation
Answer: D
Explanation: The magnetic field produced by a solenoid carrying a current is similar to that of a bar magnet, with field lines emerging from the north pole and entering the south pole. Diagram D correctly represents this field pattern.
Question 40 (P5.2.2)
Which type of radiation has the greatest ionising effect?
A infrared rays
B α-particles
C β-particles
D γ-rays
▶️Answer/Explanation
Answer: B
Explanation: α-particles are helium nuclei (2p+2n) with +2 charge and large mass, making them highly ionizing but weakly penetrating. β-particles (C) are electrons with less ionizing power. γ-rays (D) are electromagnetic waves with least ionizing but most penetrating power. Infrared (A) is non-ionizing radiation. The order of ionizing power is α > β > γ.