Question 1 (Subtopic: B1.1)
A plant is placed on a windowsill. The next day, it is found to have all of its leaves facing the light. Which of the characteristics is this plant displaying?
- a permanent increase in size and dry mass by an increase in cell number or cell size or both
- an action by an organism or part of an organism causing a change of position or place
- the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
A. 3 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3
▶️Answer/Explanation
Answer: A. 3 only
Explanation: The plant is displaying the ability to detect or sense stimuli (light) and make an appropriate response (leaves facing the light). This is characteristic 3. The other characteristics are not directly related to the plant’s response to light.
Question 2 (Subtopic: B2.2)
The length of an insect in a photograph is measured as 17 mm. The actual length of the insect is 12 mm. What is the magnification of the insect in the photograph?
A. ×1.2
B. ×1.3
C. ×1.4
D. ×1.5
▶️Answer/Explanation
Answer: C. ×1.4
Explanation: Magnification is calculated using the formula: \[ \text{Magnification} = \frac{\text{Image size}}{\text{Actual size}} \] Substituting the given values: \[ \text{Magnification} = \frac{17 \, \text{mm}}{12 \, \text{mm}} \approx 1.4 \] Therefore, the magnification is ×1.4.
Question 3 (Subtopic: B4.1)
Which type of biological molecule contains carbon, hydrogen, oxygen, and nitrogen?
A. fat
B. protein
C. reducing sugar
D. starch
▶️Answer/Explanation
Answer: B. protein
Explanation: Proteins are biological molecules that contain carbon, hydrogen, oxygen, and nitrogen. Fats and carbohydrates (like reducing sugar and starch) contain carbon, hydrogen, and oxygen but do not contain nitrogen.
Question 4 (Subtopic: 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. At 95°C, the enzyme is denatured and becomes inactive, which is why the starch remains unchanged (blue-black colour with iodine). At 35°C, the enzyme is active, and the starch is broken down, resulting in a brown colour. At 15°C, the enzyme works slowly, and at 0°C, it is inactive.
Question 5 (Subtopic: B6.1)
The diagram shows a destarched, variegated leaf that had a piece of black card attached. The leaf was left in a warm sunny location for a few days.
The card was then removed and the leaf tested for starch.
Which diagram shows the result of the starch test?
▶️Answer/Explanation
Answer: C. Diagram C
Explanation: In a variegated leaf, only the green parts contain chlorophyll and can photosynthesize to produce starch. The black card blocks light, preventing photosynthesis in the covered area. When tested with iodine, the green parts will turn blue-black (indicating starch), while the covered area will remain brown (no starch). Diagram C correctly shows this result.
Question 6 (Subtopic: 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 increase the surface area for absorption of nutrients. They do not excrete waste, secrete enzymes, or improve blood circulation.
Question 7 (Subtopic: 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 temperature, low humidity
Explanation: Transpiration is the process of water loss from plants through stomata. It is fastest under conditions of high temperature (which increases the rate of evaporation) and low humidity (which increases the water potential gradient between the leaf and the surrounding air).
Question 8 (Subtopic: B11.1)
Which row is correct for inspired air and expired air?
▶️Answer/Explanation
Answer: C. 21 oxygen, 0.04 carbon dioxide (inspired air) and 17 oxygen, 4 carbon dioxide (expired air)
Explanation: Inspired air contains approximately 21% oxygen and 0.04% carbon dioxide. During respiration, oxygen is used, and carbon dioxide is produced, so expired air contains less oxygen (around 17%) and more carbon dioxide (around 4%).
Question 9 (Subtopic: B13.1)
Which row correctly compares the hormonal and nervous systems in humans?
▶️Answer/Explanation
Answer: C. slow speed of action, long length of response (hormonal) and fast speed of action, short length of response (nervous)
Explanation: The hormonal system acts slowly but has long-lasting effects, while the nervous system acts quickly but has short-lived effects. This is because hormones travel through the bloodstream, which takes time, whereas nerve impulses travel rapidly along neurons.
Question 10 (Subtopic: B15.4)
In human reproduction, which cells are haploid?
| Gametes | Zygotes | |
|---|---|---|
| A | ✓ | ✓ |
| B | ✓ | ✗ |
| C | ✗ | ✓ |
| D | ✗ | ✗ |
▶️Answer/Explanation
Answer: B. Gametes are haploid, zygotes are not
Explanation: Gametes (sperm and egg cells) are haploid, meaning they contain half the number of chromosomes (23 in humans). When they fuse during fertilization, they form a diploid zygote (46 chromosomes).
Question 11 (Sub-topic: B16.2)
Which row about meiosis or mitosis is correct?
▶️Answer/Explanation
Answer: A
Explanation: Meiosis is the process involved in gamete formation, and it produces haploid cells. Mitosis, on the other hand, is involved in growth and produces diploid cells. Therefore, option A is correct.
Question 12 (Sub-topic: B18.2)
Which type of organism gets its energy from dead or waste organic matter?
A carnivore
B consumer
C decomposer
D producer
▶️Answer/Explanation
Answer: C
Explanation: Decomposers are organisms that break down dead or waste organic matter, recycling nutrients back into the ecosystem. Carnivores, consumers, and producers do not primarily get their energy from dead or waste organic matter.
Question 13 (Sub-topic: B19.1)
What is eutrophication caused by?
A combustion of fossil fuels
B cutting down of forests
C discarded plastic rubbish
D overuse of nitrogen-containing fertiliser
▶️Answer/Explanation
Answer: D
Explanation: Eutrophication is caused by the overuse of nitrogen-containing fertilisers, which leads to excessive growth of algae in water bodies. This can deplete oxygen levels and harm aquatic life.
Question 14 (Sub-topic: C12.4)
An aqueous salt solution contains an insoluble impurity. Which processes are used to obtain pure salt crystals?
A distil then crystallise
B distil then chromatography
C filter then crystallise
D filter then chromatography
▶️Answer/Explanation
Answer: C
Explanation: To obtain pure salt crystals from an aqueous solution containing an insoluble impurity, the solution should first be filtered to remove the insoluble impurity, and then the filtrate can be crystallised to obtain the pure salt crystals.
Question 15 (Sub-topic: C2.5)
Which dot-and-cross diagram represents a molecule of ammonia?
▶️Answer/Explanation
Answer: C
Explanation: Ammonia (NH₃) has a central nitrogen atom with three hydrogen atoms bonded to it and one lone pair of electrons. The correct dot-and-cross diagram should show this arrangement, which is represented by option C.
Question 16 (Sub-topic: C3.3)
Which sample contains the smallest number of moles of the substance?
A 12 dm³ of hydrogen at room temperature and pressure
B 500 cm³ of 0.5 mol/dm³ hydrochloric acid
C 12 g of carbon
D 20 g of calcium
▶️Answer/Explanation
Answer: B
Explanation: To determine the number of moles, we use the formula: moles = volume × concentration. For option B, 500 cm³ of 0.5 mol/dm³ hydrochloric acid is equivalent to 0.5 dm³ × 0.5 mol/dm³ = 0.25 moles. This is the smallest number of moles among the given options.
Question 17 (Sub-topic: C5.1)
Which statement describes an exothermic reaction?
A The products have less energy than the reactants and there is a decrease in temperature.
B The products have less energy than the reactants and there is an increase in temperature.
C The products have more energy than the reactants and there is a decrease in temperature.
D The products have more energy than the reactants and there is an increase in temperature.
▶️Answer/Explanation
Answer: B
Explanation: In an exothermic reaction, the products have less energy than the reactants, and energy is released to the surroundings, causing an increase in temperature.
Question 18 (Sub-topic: C6.2)
Four identical pieces of magnesium ribbon are added to separate 25 cm³ samples of dilute hydrochloric acid.
The concentrations of the four acid samples are 0.5 mol/dm³, 1.0 mol/dm³, 1.5 mol/dm³, and 2.0 mol/dm³.
The volume of hydrogen gas produced is measured at different times. The results are shown in the graph.
Which line on the graph is obtained using 1.0 mol/dm³ hydrochloric acid?
▶️Answer/Explanation
Answer: C
Explanation: The rate of reaction increases with the concentration of the acid. The line corresponding to 1.0 mol/dm³ hydrochloric acid will be intermediate between the lines for 0.5 mol/dm³ and 1.5 mol/dm³, which is represented by option C.
Question 19 (Sub-topic: 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 oxidised to carbon dioxide, and copper oxide is reduced to copper, making it a redox reaction.
Question 20 (Sub-topic: C7.3)
Which compound is prepared by reacting an acid with a base?
A calcium oxide
B copper hydroxide
C hydrogen chloride
D magnesium sulfate
▶️Answer/Explanation
Answer: D
Explanation: Magnesium sulfate is prepared by reacting an acid (sulfuric acid) with a base (magnesium hydroxide or magnesium oxide). This is a neutralisation reaction that produces a salt and water.
Question 21 (Sub-topic: C2.4)
Which statement about metallic bonding is correct?
A. There is a strong electrostatic force of attraction between a lattice of oppositely charged ions.
B. There is a strong electrostatic force of attraction between a lattice of positive ions and a sea of electrons.
C. There is a weak electrostatic force of attraction between a lattice of metal atoms and a sea of electrons.
D. There is a weak electrostatic force of attraction between a lattice of positive ions and a sea of electrons.
▶️Answer/Explanation
Answer: B
Explanation: Metallic bonding involves a lattice of positive metal ions surrounded by a “sea” of delocalized electrons. The electrostatic force of attraction between the positive ions and the delocalized electrons is strong, which is why metals have high melting and boiling points.
Question 22 (Sub-topic: C9.4)
Four different metals are separately heated with their metal oxides. The results are shown.
| oxide of W | oxide of X | oxide of Y | oxide of Z | |
|---|---|---|---|---|
| metal W | ✗ | ✗ | ✗ | ✗ |
| metal X | ✓ | ✗ | ✓ | ✓ |
| metal Y | ✓ | ✗ | ✗ | ✓ |
| metal Z | ✓ | ✗ | ✗ | ✗ |
What is the order of reactivity?
▶️Answer/Explanation
Answer: A
Explanation: The reactivity series of metals determines how easily a metal can displace another metal from its oxide. Metal X can displace metals W, Y, and Z from their oxides, indicating it is the most reactive. Metal W cannot displace any of the other metals, making it the least reactive. Therefore, the order of reactivity is X, Y, Z, W.
Question 23 (Sub-topic: C6.3)
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: When an acid reacts with a metal, hydrogen gas is produced, not carbon dioxide. The other options (B, C, and D) all produce carbon dioxide as a byproduct.
Question 24 (Sub-topic: C4.1)
In the Haber process, ammonia is manufactured using hydrogen and nitrogen. What is the source of hydrogen for this process?
A. the electrolysis of dilute sulfuric acid
B. the reaction of hydrochloric acid with zinc
C. the reaction of steam with magnesium
D. the reaction of steam with methane
▶️Answer/Explanation
Answer: D
Explanation: In the Haber process, hydrogen is typically obtained from the reaction of steam with methane (natural gas) in the presence of a catalyst. This reaction produces hydrogen gas and carbon monoxide, which is further processed to produce more hydrogen.
Question 25 (Sub-topic: C5.1)
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: In the Contact process, a vanadium(V) oxide catalyst is used, not nickel. The other statements (B, C, and D) are correct steps in the Contact process.
Question 26 (Sub-topic: C11.6)
Ethanol is formed by fermentation and by the addition of steam to ethene. What is used to catalyse these reactions?
| fermentation | addition of steam | |
|---|---|---|
| A | glucose | nickel |
| B | yeast | nickel |
| C | glucose | phosphoric acid |
| D | yeast | phosphoric acid |
▶️Answer/Explanation
Answer: D
Explanation: In fermentation, yeast is used to convert glucose into ethanol. In the addition of steam to ethene, phosphoric acid is used as a catalyst to produce ethanol.
Question 27 (Sub-topic: 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 addition polymerisation, ethene acts as the monomer, which is the small molecule that joins together to form the polymer, poly(ethene).
Question 28 (Sub-topic: P1.2)
An object travelling in a straight line accelerates from a speed of 6.0 m/s to a speed of 15 m/s in 6.0 s. What is the acceleration of the object?
A. 1.0 m/s2
B. 1.5 m/s2
C. 2.5 m/s2
D. 3.5 m/s2
▶️Answer/Explanation
Answer: B
Explanation: Acceleration is calculated using the formula: \[ a = \frac{\Delta v}{\Delta t} = \frac{15 \, \text{m/s} – 6 \, \text{m/s}}{6 \, \text{s}} = \frac{9 \, \text{m/s}}{6 \, \text{s}} = 1.5 \, \text{m/s}^2 \] Therefore, the acceleration is 1.5 m/s2.
Question 29 (Sub-topic: P1.7)
A cylinder of weight \( W \) and cross-sectional area \( X \) exerts a pressure \( P \) on the ground.
Some changes are made to \( W \) and to \( X \). Which row shows a situation that produces the same pressure \( P \) on the ground?
| W | X | |
|---|---|---|
| A | doubled | doubled |
| B | doubled | halved |
| C | unchanged | doubled |
| D | unchanged | halved |
▶️Answer/Explanation
Answer: A
Explanation: Pressure is calculated using the formula: \[ P = \frac{W}{X} \] If both \( W \) and \( X \) are doubled, the pressure \( P \) remains the same because: \[ P = \frac{2W}{2X} = \frac{W}{X} \] Therefore, the pressure remains unchanged.
Question 30 (Sub-topic: P1.6)
A box of mass 8.0 kg is lifted vertically from the ground on to a shelf that is 2.0 m above the ground. The gravitational field strength \( g \) is 10 N/kg. How much work is done as the box is lifted on to the shelf?
A. 4.0 J
B. 16 J
C. 40 J
D. 160 J
▶️Answer/Explanation
Answer: D
Explanation: Work done is calculated using the formula: \[ W = m \times g \times h = 8.0 \, \text{kg} \times 10 \, \text{N/kg} \times 2.0 \, \text{m} = 160 \, \text{J} \] Therefore, the work done is 160 J.
Question 31 (Sub-topic: 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 power stations generate electricity by using the kinetic energy of flowing water to drive turbines, without the need for steam. The other power stations (A, B, and D) use steam to drive turbines.
Question 32 (Sub-topic: P2.3)
An electric kettle is switched on and the temperature of the water in it increases to 60°C. What is the main method of heat transfer within the water?
A. boiling
B. conduction
C. convection
D. radiation
▶️Answer/Explanation
Answer: C
Explanation: In a kettle, heat is transferred through the water mainly by convection. Hot water rises, and cooler water sinks, creating a convection current that distributes heat throughout the water.
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 (Sub-topic: 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 the angle of incidence is greater than the critical angle, total internal reflection occurs. The ray of light will reflect back into the glass and continue in the direction labelled D.
Question 35 (Sub-topic: P4.2.4)
Which statement about an NTC thermistor is correct?
A. As its temperature increases its resistance decreases.
B. As its temperature increases its resistance increases.
C. As the brightness of light falling on it increases its resistance decreases.
D. As the brightness of light falling on it increases its resistance increases.
▶️Answer/Explanation
Answer: A
Explanation: An NTC (Negative Temperature Coefficient) thermistor decreases in resistance as its temperature increases. This is because the number of charge carriers increases with temperature, reducing the resistance.
Question 36 (Sub-topic: P4.3.2)
A 12Ω resistor and a 4.0Ω resistor are connected across the terminals of a 12V battery.
There is a voltmeter connected across the 12Ω resistor. What is the reading on the voltmeter?
A. 3.0V
B. 8.0V
C. 9.0V
D. 12V
▶️Answer/Explanation
Answer: C
Explanation: The total resistance in the circuit is 12Ω + 4Ω = 16Ω. The current in the circuit is I = V/R = 12V / 16Ω = 0.75A. The voltage across the 12Ω resistor is V = IR = 0.75A * 12Ω = 9V.
Question 37 (Sub-topic: P4.2.5)
An electric oven has a power rating of 2.0kW when connected to a 250V power supply. What is the current in the oven?
A. 0.13A
B. 8.0A
C. 130A
D. 500A
▶️Answer/Explanation
Answer: B
Explanation: Power (P) is given by P = VI, where V is voltage and I is current. Rearranging for current, I = P/V = 2000W / 250V = 8A.
Question 38 (Sub-topic: P4.4)
An electric kettle is designed so that the usual current in its heater is 9.0 A. The owner of the kettle fits the plug with a fuse rated at 3 A. What happens when the kettle is filled with water and switched on?
A. The current in the circuit increases to greater than 9.0 A.
B. The fuse blows immediately and the kettle fails to operate.
C. The water reaches boiling point more quickly due to an increase in the voltage.
D. The water reaches boiling point more slowly due to a decrease in the current.
▶️Answer/Explanation
Answer: B
Explanation: The fuse is rated at 3A, which is much lower than the usual current of 9A in the kettle. When the kettle is switched on, the current will exceed the fuse’s rating, causing it to blow and cutting off the circuit, preventing the kettle from operating.
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 (Sub-topic: 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 have the greatest ionising effect because they are relatively large and carry a double positive charge, allowing them to interact strongly with matter and ionise atoms they collide with.