Question 1 (Topic – B1.1)
Ten woodlice were placed in a dish. Half of the dish was dark and the other half of the dish was light. At the end of one hour, all of the woodlice had moved to the dark side of the dish. Which characteristic of living organisms does this experiment demonstrate in woodlice?
A respiration
B excretion
C nutrition
D sensitivity
▶️Answer/Explanation
Answer: D
Explanation: The experiment demonstrates sensitivity, as the woodlice respond to the environmental stimulus (light) by moving to the dark side of the dish. This is a characteristic of living organisms, where they detect and respond to changes in their environment.
Question 2 (Topic – B3.2)
What is an example of osmosis?
A a dried out piece of leaf stalk swelling up when placed in a bowl of water
B carbon dioxide entering a leaf when it is photosynthesising
C red blood cells travelling to the lungs to collect oxygen
D the passage of digested food molecules through the wall of the small intestine
▶️Answer/Explanation
Answer: A
Explanation: Osmosis is the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. The swelling of a dried-out leaf stalk when placed in water is an example of osmosis, as water moves into the cells of the leaf stalk.
Question 3 (Topic – C2.2)
Which molecule contains carbon?
A ammonia
B fat
C sulfuric acid
D water
▶️Answer/Explanation
Answer: B
Explanation: Fat is an organic molecule that contains carbon. Ammonia (NH₃), sulfuric acid (H₂SO₄), and water (H₂O) do not contain carbon.
Question 4 (Topic – B5.1)
The graph shows the effect of temperature on the rate of an enzyme-controlled reaction.
Which statements are correct?
1 Enzyme molecules denature above 60 °C and below 20 °C.
2 Increasing the temperature between 10 °C and 40 °C increases kinetic energy of enzyme molecules.
3 The shape of the active site changes between 40 °C and 60 °C.
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3
▶️Answer/Explanation
Answer: C
Explanation: Statement 1 is incorrect because enzymes do not denature below 20 °C; they simply become less active. Statement 2 is correct because increasing the temperature within the optimal range (10 °C to 40 °C) increases the kinetic energy of enzyme molecules, leading to more frequent collisions with substrates. Statement 3 is correct because as the temperature approaches 60 °C, the enzyme’s active site begins to change shape, leading to denaturation.
Question 5 (Topic – B6.1)
What will cause plant leaves to turn yellow?
A a lack of magnesium in the soil
B a lack of starch in the leaves
C a reduction in the rate of photosynthesis
D a reduction in the rate of respiration
▶️Answer/Explanation
Answer: A
Explanation: Magnesium is a key component of chlorophyll, the pigment responsible for the green color in leaves. A lack of magnesium in the soil leads to chlorophyll deficiency, causing the leaves to turn yellow, a condition known as chlorosis.
Question 6 (Topic – B5.1)
The diagram shows the optimum pH for two different enzymes X and Y.
Which enzyme, X or Y, could be amylase and from which organ could this amylase be secreted?
A X, pancreas
B X, stomach
C Y, pancreas
D Y, stomach
▶️Answer/Explanation
Answer: C
Explanation: Amylase is an enzyme that breaks down starch and has an optimum pH around 7, which is neutral. The pancreas secretes amylase into the small intestine, where the pH is close to neutral. Therefore, enzyme Y, which has an optimum pH around 7, is likely to be amylase secreted by the pancreas.
Question 7 (Topic – B8.1)
The diagram shows a transverse section through a plant stem.
Which tissue is X?
A mesophyll
B phloem
C epidermis
D xylem
▶️Answer/Explanation
Answer: B
Explanation: In a transverse section of a plant stem, the phloem is typically located towards the outer part of the vascular bundle, while the xylem is located towards the inner part. Therefore, tissue X is likely to be the phloem, which is responsible for transporting sugars and other nutrients throughout the plant.
Question 8 (Topic – B11.1)
A person ran up as many stairs as they could in one minute. What would be the effect on their breathing?
A depth of breathing decreased, rate of breathing decreased
B depth of breathing decreased, rate of breathing increased
C depth of breathing increased, rate of breathing decreased
D depth of breathing increased, rate of breathing increased
▶️Answer/Explanation
Answer: D
Explanation: During intense physical activity, such as running up stairs, the body requires more oxygen to meet the increased energy demand. This leads to an increase in both the depth and rate of breathing to supply more oxygen to the muscles and remove carbon dioxide more efficiently.
Question 9 (Topic – B13.1)
The drug atropine is used to stop the pupil narrowing when a bright light is shone into the eye. Which statement explains how atropine stops the pupil narrowing?
A Atropine prevents circular muscles contracting.
B Atropine prevents radial muscles contracting.
C Atropine causes circular muscles to contract.
D Atropine causes radial muscles to relax.
▶️Answer/Explanation
Answer: A
Explanation: Atropine is a drug that blocks the action of the parasympathetic nervous system, which normally causes the circular muscles of the iris to contract, narrowing the pupil. By preventing the contraction of these muscles, atropine keeps the pupil dilated, even in bright light.
Question 10 (Topic – B15.3)
In which structure is pollen made?
A anther
B ovary
C sepal
D stigma
▶️Answer/Explanation
Answer: A
Explanation: Pollen is produced in the anther, which is part of the stamen, the male reproductive organ of a flower. The anther contains pollen sacs where pollen grains are formed through meiosis.
Question 11 (Topic – B16.2)
Four processes which require the production of new cells are listed.
1 asexual reproduction
2 gamete production
3 growth
4 replacement of worn out cells
Which processes are brought about by mitosis?
A 1 and 2 only
B 1, 2 and 3
C 1, 3 and 4
D 2, 3 and 4
▶️Answer/Explanation
Answer: C
Explanation: Mitosis is a type of cell division that results in two daughter cells with the same number of chromosomes as the parent cell. It is involved in asexual reproduction, growth, and the replacement of worn-out cells. Gamete production, however, involves meiosis, which produces cells with half the number of chromosomes.
Question 12 (Topic – B18.1)
What is an ecosystem?
A a chart showing the flow of energy from one organism to another
B a diagram giving the energy level of an organism in its environment
C a network of interconnected organisms
D a unit containing all of the organisms and their environment
▶️Answer/Explanation
Answer: D
Explanation: An ecosystem is a unit that includes all the organisms (biotic factors) and their physical environment (abiotic factors) interacting as a system. It encompasses the flow of energy and cycling of nutrients within the environment.
Question 13 (Topic – B18.3)
The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration?
A A
B B
C C
D D
▶️Answer/Explanation
Answer: C
Explanation: In the carbon cycle, respiration is the process by which organisms release carbon dioxide into the atmosphere. Arrow C likely represents this process, as it shows the release of CO₂ from organisms (such as animals) back into the atmosphere.
Question 14 (Topic – C2.2)
The protons, neutrons and electrons in a particle are shown.
Which symbol represents this particle?
A F
B F
C Ne
D Ne⁺
▶️Answer/Explanation
Answer: B
Explanation: The particle described has 9 protons, 10 neutrons, and 9 electrons. This corresponds to fluorine (F), which has an atomic number of 9. The symbol F represents a neutral fluorine atom.
Question 15 (Topic – C2.6)
Which statements explain why graphite conducts electricity and acts as a lubricant?
1 It has many strong covalent bonds.
2 It has mobile electrons.
3 It has weak forces between sheets of carbon atoms.
4 It is a macromolecule.
A 1 and 2
B 1 and 4
C 2 and 3
D 3 and 4
▶️Answer/Explanation
Answer: C
Explanation: Graphite conducts electricity because it has delocalized electrons that are free to move (statement 2). It acts as a lubricant because the weak forces between its layers of carbon atoms allow the layers to slide over each other easily (statement 3).
Question 16 (Topic – C3.2)
Which compounds have different relative molecular masses?
A C₂H₆ and NO
B CO₂ and N₂O
C H₂O₂ and H₂S
D NH₃ and C₂H₄
▶️Answer/Explanation
Answer: D
Explanation: NH₃ (ammonia) has a relative molecular mass of 17 (14 + 3), while C₂H₄ (ethene) has a relative molecular mass of 28 (2 × 12 + 4). These two compounds have different relative molecular masses.
Question 17 (Topic – C4.1)
The diagram shows the electrolysis of a compound.
When the switch is closed, the solution around electrode P turns orange because a halogen is formed. The positive electrode P is called the ……1……, and the halogen is ……2…… . Which words complete gaps 1 and 2?
A anode, bromine
B anode, chlorine
C cathode, bromine
D cathode, chlorine
▶️Answer/Explanation
Answer: A
Explanation: In electrolysis, the positive electrode is called the anode. Bromine is a halogen that forms an orange solution, so the halogen formed at the anode is bromine.
Question 18 (Topic – C6.2)
In experiment 1, dilute hydrochloric acid is added to an excess of solid calcium carbonate. In experiment 2, the concentration of the acid is halved and the volume of acid used is doubled. The same mass and size of solid calcium carbonate is used in both experiments. Which row about the two experiments is correct?
A number of particles possessing the activation energy: equal in both experiments, frequency of reactant particle collisions: equal in both experiments
B number of particles possessing the activation energy: equal in both experiments, frequency of reactant particle collisions: greater in experiment 1
C number of particles possessing the activation energy: greater in experiment 1, frequency of reactant particle collisions: greater in experiment 1
D number of particles possessing the activation energy: greater in experiment 1, frequency of reactant particle collisions: equal in both experiments
▶️Answer/Explanation
Answer: B
Explanation: The number of particles possessing the activation energy depends on temperature, which is the same in both experiments. However, the frequency of collisions is higher in experiment 1 because the concentration of the acid is higher, leading to more frequent collisions between acid particles and calcium carbonate.
Question 19 (Topic – C6.3)
The ionic equation for the reaction between chlorine and potassium bromide is shown. What is the oxidising agent?
A Br₂
B Br⁻
C Cl₂
D Cl⁻
▶️Answer/Explanation
Answer: C
Explanation: In the reaction, chlorine (Cl₂) gains electrons to form chloride ions (Cl⁻), so it is reduced. The species that is reduced is the oxidizing agent. Therefore, chlorine is the oxidizing agent in this reaction.
Question 20 (Topic – C7.1)
Aqueous ammonium chloride reacts with aqueous potassium hydroxide. The equation is shown. What is the role of the ammonium ion in this reaction?
A an acid
B a base
C an electron acceptor
D an electron donor
▶️Answer/Explanation
Answer: A
Explanation: The ammonium ion (NH₄⁺) donates a proton (H⁺) to the hydroxide ion (OH⁻), forming water (H₂O) and ammonia (NH₃). This behavior is characteristic of an acid, which is a proton donor.
Question 21 (Topic – C8.2)
Which statement about the elements in Group I and in Group VII of the Periodic Table is correct?
A Chlorine has a darker colour than iodine.
B Each molecule of a halogen contains one atom.
C Potassium reacts with cold water more vigorously than lithium.
D The melting point of lithium is lower than the melting point of sodium.
▶️Answer/Explanation
Answer: C
Explanation: Potassium is more reactive than lithium because it has a larger atomic radius and its outermost electron is farther from the nucleus, making it easier to lose. This results in a more vigorous reaction with cold water.
Question 22 (Topic – C9.3)
Why does the steel used to make a drill contain manganese?
A to increase the density of the steel
B to increase the hardness of the steel
C to increase the malleability of the steel
D to increase the melting point of the steel
▶️Answer/Explanation
Answer: B
Explanation: Manganese is added to steel to increase its hardness and strength. This makes the steel more suitable for use in tools like drills, which need to be durable and resistant to wear.
Question 23 (Topic – C9.5)
A block of zinc is attached to an underground steel pipe as shown. The zinc stops the steel rusting by sacrificial protection. Which statement is not correct?
A Zinc is more reactive than the iron in steel.
B Zinc is oxidised in preference to the iron in steel.
C Zinc prevents oxygen from reaching the steel.
D Zinc transfers electrons to the iron in the steel.
▶️Answer/Explanation
Answer: C
Explanation: Sacrificial protection works because zinc is more reactive than iron and oxidizes in preference to iron, not because it prevents oxygen from reaching the steel. Zinc does not block oxygen; instead, it corrodes first, protecting the steel.
Question 24 (Topic – C10.2)
Some cars have catalytic converters in their exhaust systems. Some of the gases produced when petrol burns are listed. Which gases are removed in catalytic converters?
1 carbon dioxide
2 carbon monoxide
3 oxides of nitrogen
A 1, 2 and 3
B 1 and 2 only
C 1 and 3 only
D 2 and 3 only
▶️Answer/Explanation
Answer: D
Explanation: Catalytic converters remove harmful gases such as carbon monoxide (CO) and oxides of nitrogen (NOₓ) by converting them into less harmful substances like carbon dioxide (CO₂) and nitrogen (N₂). Carbon dioxide is not removed; it is a product of the reaction.
Question 25 (Topic – C6.3)
Which equation does not represent a reaction in the Contact process?
A H₂O + SO₃ → H₂SO₄
B H₂S₂O₇ + H₂O → 2H₂SO₄
C S + O₂ → SO₂
D 2SO₂ + O₂ ⇌ 2SO₃
▶️Answer/Explanation
Answer: A
Explanation: The Contact process involves the production of sulfuric acid (H₂SO₄) from sulfur dioxide (SO₂). The reaction H₂O + SO₃ → H₂SO₄ is part of the process, but it is not a redox reaction. The other equations involve redox reactions, such as the oxidation of sulfur (S) to sulfur dioxide (SO₂) and the oxidation of sulfur dioxide (SO₂) to sulfur trioxide (SO₃).
Question 26 (Topic – C10.1)
Which statements about limestone are correct?
1 Limestone is used to neutralise industrial waste products.
2 Limestone is used to treat acidic soil.
3 Thermal decomposition of limestone produces calcium oxide.
A 1 and 2 only
B 1 and 3 only
C 2 and 3 only
D 1, 2 and 3
▶️Answer/Explanation
Answer: D
Explanation: Limestone (calcium carbonate, CaCO₃) is used to neutralize acidic industrial waste and soil because it reacts with acids to form neutral compounds. Additionally, when heated, limestone undergoes thermal decomposition to produce calcium oxide (CaO) and carbon dioxide (CO₂).
Question 27 (Topic – C11.2)
Four molecules are shown. Which structure represents ethanol?
A CH₃CH₂OH
B CH₃COOH
C CH₃CH₂CH₂OH
D CH₃CH₂OCH₃
▶️Answer/Explanation
Answer: A
Explanation: Ethanol has the molecular formula CH₃CH₂OH, where a hydroxyl group (-OH) is attached to a two-carbon chain. This matches option A.
Question 28 (Topic – P1.5)
Four force–extension graphs are shown. Which graph represents a spring that obeys Hooke’s Law?
A Graph A
B Graph B
C Graph C
D Graph D
▶️Answer/Explanation
Answer: D
Explanation: Hooke’s Law states that the extension of a spring is directly proportional to the force applied, provided the elastic limit is not exceeded. Graph D shows a straight line passing through the origin, indicating a linear relationship between force and extension, which is characteristic of a spring obeying Hooke’s Law.
Question 29 (Topic- P1.5)
When driving cars on soft sand, drivers are advised to reduce the pressure of the air in the tyres. Why does this cause the cars to sink less into the sand?
A The area of the tyres in contact with the sand is decreased.
B The area of the tyres in contact with the sand is increased.
C The downward force on the sand is decreased.
D The downward force on the sand is increased.
▶️Answer/Explanation
Answer: B
Explanation: Reducing the air pressure in the tyres increases the area of contact between the tyres and the sand. This distributes the car’s weight over a larger area, reducing the pressure on the sand and preventing the car from sinking as much.
Question 30 (Topic – P1.6)
A ball of mass 0.25 kg is thrown from the ground to a height of 5.0 m. The gravitational field strength \( g \) is 10 N/kg. Which expression gives the increase in gravitational potential energy of
A \( [(0.25 \times 10) + 5.0] \, \text{J} \)
B \( [0.25 \times 10 \times 5.0] \, \text{J} \)
C \( \left[ \frac{5.0}{(0.25 \times 10)} \right] \, \text{J} \)
D \( [(5.0 + 0.25) \times 10] \, \text{J} \)
▶️Answer/Explanation
Answer: B
Explanation: The increase in gravitational potential energy is calculated using the formula \( \Delta E_p = mgh \), where \( m \) is the mass, \( g \) is the gravitational field strength, and \( h \) is the height. Substituting the values gives \( \Delta E_p = 0.25 \times 10 \times 5.0 \).
Question 31 (Topic – P1.6)
A lamp produces 760 J of wasted energy for every 1000 J of electrical energy supplied to it. What is the efficiency of the lamp?
A 0.24%
B 0.76%
C 24%
D 76%
▶️Answer/Explanation
Answer: C
Explanation: Efficiency is calculated as the useful energy output divided by the total energy input, multiplied by 100. The useful energy output is \( 1000 \, \text{J} – 760 \, \text{J} = 240 \, \text{J} \). Therefore, the efficiency is \( \frac{240}{1000} \times 100 = 24\% \).
Question 32 (Topic – P2.2)
Which labelled arrow on the diagram represents condensation?
A A
B B
C C
D D
▶️Answer/Explanation
Answer: A
Explanation: Condensation is the process where a gas turns into a liquid. Arrow A likely represents this process, as it shows the transition from the gas phase to the liquid phase.
Question 33 (Topic – P2.3)
Thermal energy can be transferred through a solid metal by conduction. Which row describes how the molecules and free electrons in a solid metal behave during this process?
A molecules: move throughout the solid, free electrons: move throughout the solid
B molecules: move throughout the solid, free electrons: vibrate about fixed positions
C molecules: vibrate about fixed positions, free electrons: move throughout the solid
D molecules: vibrate about fixed positions, free electrons: vibrate about fixed positions
▶️Answer/Explanation
Answer: C
Explanation: In a solid metal, molecules vibrate about fixed positions, but free electrons can move throughout the solid. This movement of free electrons is responsible for the high thermal conductivity of metals.
Question 34 (Topic – P3.2)
The diagram shows a ray of light striking a plane mirror.
What is the angle of reflection?
A 20°
B 40°
C 70°
D 90°
▶️Answer/Explanation
Answer: C
Explanation: The angle of reflection is equal to the angle of incidence. If the angle of incidence is 70°, then the angle of reflection is also 70°.
Question 35 (Topic – P3.1)
The diagram represents a wave in air. Molecules are closer together in region P than they are in region Q.
Which type of wave is represented, and in which direction do the molecules vibrate?
A longitudinal, parallel to the wave direction
B longitudinal, perpendicular to the wave direction
C transverse, parallel to the wave direction
D transverse, perpendicular to the wave direction
▶️Answer/Explanation
Answer: A
Explanation: The wave described is a longitudinal wave, where molecules vibrate parallel to the direction of wave propagation. In a longitudinal wave, regions of compression (where molecules are closer together) and rarefaction (where molecules are farther apart) occur.
Question 36 (Topic – P4.2)
A rod is rubbed with a dry piece of cloth. A scientist holds the rod in her hand and brings it close to a negatively charged plastic strip. The strip is suspended by an insulating thread.
As the rod approaches the plastic strip, the strip moves towards the rod. Which statement is correct?
A The rod is a negatively charged electrical conductor.
B The rod is a negatively charged electrical insulator.
C The rod is a positively charged electrical conductor.
D The rod is a positively charged electrical insulator.
▶️Answer/Explanation
Answer: D
Explanation: The negatively charged plastic strip is attracted to the rod, indicating that the rod is positively charged. Since the rod is held in the hand and does not discharge, it is likely an insulator.
Question 37 (Topic – P4.3)
The diagrams show four circuits, each with two points X and Y labelled. Two circuits include an NTC thermistor and two circuits include an LDR. Which circuit produces a potential difference (p.d.) between points X and Y that increases as the temperature increases?
A Circuit A
B Circuit B
C Circuit C
D Circuit D
▶️Answer/Explanation
Answer: A
Explanation: An NTC thermistor decreases its resistance as temperature increases. In Circuit A, the thermistor is part of a potential divider, and as its resistance decreases, the potential difference across it (between X and Y) increases.
Question 38 (Topic – P4.4)
A hairdryer is protected by a 10 A fuse. What is the purpose of the fuse?
A It decreases the current in the hairdryer to 10 A when the current is more than 10 A.
B It increases the current in the hairdryer to 10 A when the current is less than 10 A.
C It maintains a constant temperature in the hairdryer.
D It melts when the current in the hairdryer is greater than 10 A.
▶️Answer/Explanation
Answer: D
Explanation: A fuse is a safety device that melts and breaks the circuit when the current exceeds a certain value (in this case, 10 A). This prevents damage to the hairdryer and reduces the risk of fire.
Question 39 (Topic – P4.5)
The diagram shows a wire carrying an electric current in the direction shown. The wire is at right angles to a magnetic field that is directed into the page. A force acts on the wire because of the current and the magnetic field. In which labelled direction does this force act?
A A
B B
C C
D D
▶️Answer/Explanation
Answer: B
Explanation: According to Fleming’s Left-Hand Rule, the force on a current-carrying wire in a magnetic field is perpendicular to both the current and the magnetic field. In this case, the force acts in direction B.
Question 40 (Topic – P5.2)
A uranium nucleus decays by emitting an α-particle. The nuclide equation shows this decay.
What are the numbers X and Y?
A X: 234, Y: 90
B X: 234, Y: 92
C X: 238, Y: 90
D X: 238, Y: 92
▶️Answer/Explanation
Answer: C
Explanation: When a uranium nucleus emits an α-particle (which consists of 2 protons and 2 neutrons), its atomic number decreases by 2 and its mass number decreases by 4. Therefore, X is 238 (mass number) and Y is 90 (atomic number).