Question 1 (Sub-topic – B1.1)
Which processes do green plants carry out?
- detect stimuli and make appropriate responses
- break down nutrient molecules to release energy for metabolism
- take in carbon dioxide, water and ions for energy, growth and development
A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) 1, 2 and 3
▶️Answer/Explanation
Answer: D) 1, 2 and 3
Explanation: Green plants carry out all three processes: they detect stimuli and respond (e.g., phototropism), break down nutrient molecules through respiration to release energy, and take in carbon dioxide, water, and ions for photosynthesis, growth, and development.
Question 2 (Sub-topic – B2.1)
The diagram shows a plant cell as seen under a light microscope.
Which structure is also found in animal cells?
A) B
B) C
C) D
D) A
▶️Answer/Explanation
Answer: A) B
Explanation: The structure labeled B is the nucleus, which is present in both plant and animal cells. The other structures (A, C, D) are specific to plant cells, such as the cell wall, chloroplasts, and large central vacuole.
Question 3 (Sub-topic – C2.1)
Which molecule contains carbon?
A) ammonia
B) fat
C) sulfuric acid
D) water
▶️Answer/Explanation
Answer: B) fat
Explanation: Fats are organic molecules that contain carbon atoms. Ammonia (NH₃), sulfuric acid (H₂SO₄), and water (H₂O) do not contain carbon.
Question 4 (Sub-topic – B5.1)
The graph shows the effect of temperature on an enzyme’s activity.
The three statements describe what is happening at different positions on the graph.
What is the correct order for the statements as the temperature increases?
- The maximum frequency of effective collisions is happening.
- The enzyme is denatured.
- Kinetic energy of the molecules increases so the rate of reaction increases.
A) 1 → 2 → 3
B) 1 → 3 → 2
C) 2 → 3 → 1
D) 3 → 1 → 2
▶️Answer/Explanation
Answer: D) 3 → 1 → 2
Explanation: As temperature increases, the kinetic energy of molecules increases, leading to more frequent collisions (3). At the optimum temperature, the maximum frequency of effective collisions occurs (1). Beyond this temperature, the enzyme denatures and activity decreases (2).
Question 5 (Sub-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) a lack of magnesium in the soil
Explanation: Magnesium is a key component of chlorophyll, the pigment responsible for the green color in leaves. A deficiency in magnesium leads to chlorosis, causing leaves to turn yellow.
Question 6 (Sub-topic – B7.2)
What is the name of the process which moves soluble food molecules through the wall of the small intestine into the blood?
A) absorption
B) assimilation
C) digestion
D) ingestion
▶️Answer/Explanation
Answer: A) absorption
Explanation: Absorption is the process by which soluble food molecules pass through the wall of the small intestine into the bloodstream. Assimilation involves the uptake and use of these nutrients by cells, while digestion breaks down food into smaller molecules, and ingestion is the intake of food.
Question 7 (Sub-topic – B9.2)
Which statement correctly describes the opening and closing of the valves in the heart during contraction of the ventricles?
A) The atrioventricular valves close and the semi-lunar valves close.
B) The atrioventricular valves close and the semi-lunar valves open.
C) The atrioventricular valves open and the semi-lunar valves close.
D) The atrioventricular valves open and the semi-lunar valves open.
▶️Answer/Explanation
Answer: B) The atrioventricular valves close and the semi-lunar valves open.
Explanation: During ventricular contraction, the atrioventricular valves (tricuspid and bicuspid) close to prevent backflow of blood into the atria, while the semi-lunar valves (aortic and pulmonary) open to allow blood to be pumped out of the heart into the arteries.
Question 8 (Sub-topic – B11.1)
The graph shows the changes in volume of air in the lungs at rest and during exercise.
What was the effect of exercise on the rate and depth of breathing?
| rate of breathing | depth of breathing | |
|---|---|---|
| A | decrease | decrease |
| B | decrease | increase |
| C | increase | decrease |
| D | increase | increase |
▶️Answer/Explanation
Answer: D) increase, increase
Explanation: During exercise, both the rate (number of breaths per minute) and depth (volume of air per breath) of breathing increase to meet the increased oxygen demand and to remove more carbon dioxide from the body.
Question 9 (Sub-topic – B13.2)
Adrenaline increases blood glucose concentration. It does this by changing the levels of glucagon and insulin. Which row is correct?
| adrenaline level | glucagon level | insulin level | |
|---|---|---|---|
| A | decrease | decrease | decrease |
| B | decrease | increase | increase |
| C | increase | increase | increase |
| D | increase | increase | decrease |
▶️Answer/Explanation
Answer: D) increase, increase, decrease
Explanation: Adrenaline increases blood glucose levels by stimulating the release of glucagon, which promotes glycogen breakdown in the liver, and by inhibiting insulin secretion, which would otherwise lower blood glucose levels.
Question 10 (Sub-topic – B15.4)
Which row describes the exchange of substances between a mother and her fetus in mammals?
| substances moving from the mother to fetus | substances moving from the fetus to mother | |
|---|---|---|
| A | glucose and carbon dioxide | urea and oxygen |
| B | glucose and oxygen | urea and carbon dioxide |
| C | urea and carbon dioxide | glucose and oxygen |
| D | urea and oxygen | glucose and carbon dioxide |
▶️Answer/Explanation
Answer: B) glucose and oxygen, urea and carbon dioxide
Explanation: The mother provides glucose and oxygen to the fetus for energy and growth, while the fetus returns waste products like urea and carbon dioxide to the mother for excretion.
Question 11 (Sub-topic – B16.3)
The pedigree diagram shows inheritance of a disease caused by a dominant allele.
Which statement is correct?
A) Individual 1 is homozygous dominant.
B) Individual 2 is homozygous dominant.
C) Individual 3 is homozygous recessive.
D) Individual 4 is heterozygous.
▶️Answer/Explanation
Answer: C) Individual 3 is homozygous recessive.
Explanation: In a pedigree diagram, if a disease is caused by a dominant allele, unaffected individuals must be homozygous recessive. Individual 3 is unaffected, so they must be homozygous recessive.
Question 12 (Sub-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) a unit containing all of the organisms and their environment
Explanation: An ecosystem is a community of living organisms (biotic factors) interacting with their physical environment (abiotic factors) as a system.
Question 13 (Sub-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) C
Explanation: Respiration is the process by which organisms release carbon dioxide into the atmosphere. In the carbon cycle, this is represented by an arrow from living organisms to the atmosphere.
Question 14 (Sub-topic – C6.1)
Which row correctly identifies the named changes?
| physical changes | chemical changes | |
|---|---|---|
| A | condensation and combustion | evaporation and neutralisation |
| B | evaporation and neutralisation | condensation and combustion |
| C | condensation and evaporation | combustion and neutralisation |
| D | combustion and neutralisation | condensation and evaporation |
▶️Answer/Explanation
Answer: C) condensation and evaporation, combustion and neutralisation
Explanation: Condensation and evaporation are physical changes as they involve a change in state without altering the chemical composition. Combustion and neutralisation are chemical changes as they involve the formation of new substances.
Question 15 (Sub-topic – C2.6)
Which statements explain why graphite conducts electricity and why it can act as a lubricant?
- It is a macromolecule.
- It has mobile electrons.
- It has strong covalent bonds.
- It has weak forces between its layers.
A) 1 and 3
B) 1 and 4
C) 2 and 3
D) 2 and 4
▶️Answer/Explanation
Answer: D) 2 and 4
Explanation: Graphite conducts electricity due to the presence of mobile electrons within its layers. It acts as a lubricant because the weak forces between its layers allow them to slide over each other easily.
Question 16 (Sub-topic – C4.1)
When aqueous chlorine is added to aqueous potassium bromide, bromine is produced. What is the ionic equation for this reaction?
A) \( \text{Cl}_2 + \text{Br}^- \rightarrow 2\text{Cl}^- + \text{Br} \)
B) \( \text{Cl}_2 + 2\text{Br}^- \rightarrow 2\text{Cl}^- + \text{Br}_2 \)
C) \( \text{Cl}_2 + 2\text{Br}^- \rightarrow \text{Cl}^- + \text{Br}_2 \)
D) \( \text{Cl}_2 + 2\text{KBr} \rightarrow 2\text{KCl} + \text{Br}_2 \)
▶️Answer/Explanation
Answer: B) \( \text{Cl}_2 + 2\text{Br}^- \rightarrow 2\text{Cl}^- + \text{Br}_2 \)
Explanation: This is the correct ionic equation for the reaction where chlorine displaces bromine from potassium bromide, forming chloride ions and bromine molecules.
Question 17 (Sub-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?
| 1 | 2 | |
|---|---|---|
| A | anode | bromine |
| B | anode | chlorine |
| C | cathode | bromine |
| D | cathode | chlorine |
▶️Answer/Explanation
Answer: A) anode, bromine
Explanation: The positive electrode is the anode, where oxidation occurs. Bromine is a halogen that forms an orange solution, indicating its presence.
Question 18 (Sub-topic – C6.2)
Calcium carbonate reacts with dilute hydrochloric acid. The equation for this reaction is shown. Which methods are suitable for investigating the rate of this reaction?
1) observing a colour change
2) measuring gas volume
3) measuring mass
A) 1, 2 and 3
B) 1 and 2 only
C) 1 and 3 only
D) 2 and 3 only
▶️Answer/Explanation
Answer: D) 2 and 3 only
Explanation: The rate of reaction can be measured by monitoring the volume of gas produced (CO₂) or by measuring the decrease in mass as CO₂ is released. There is no significant colour change in this reaction.
Question 19 (Sub-topic – C6.3)
Which equation shows a reaction in which a metal is reduced?
A) \( \text{CuCO}_3 \rightarrow \text{CuO} + \text{CO}_2 \)
B) \( 2\text{Li} + 2\text{H}_2\text{O} \rightarrow 2\text{LiOH} + \text{H}_2 \)
C) \( 2\text{Fe}^{3+} + 2\text{I}^- \rightarrow \text{Fe}^{2+} + \text{I}_2 \)
D) \( \text{Mg} + 2\text{H}^+ \rightarrow \text{Mg}^{2+} + \text{H}_2 \)
▶️Answer/Explanation
Answer: C) \( 2\text{Fe}^{3+} + 2\text{I}^- \rightarrow \text{Fe}^{2+} + \text{I}_2 \)
Explanation: In this reaction, iron (Fe³⁺) is reduced to Fe²⁺, gaining electrons. The other reactions involve oxidation or decomposition, not reduction.
Question 20 (Sub-topic – C7.2)
Zinc oxide reacts with both dilute sulfuric acid and aqueous sodium hydroxide. Which type of oxide is zinc oxide?
A) acidic
B) amphoteric
C) basic
D) neutral
▶️Answer/Explanation
Answer: B) amphoteric
Explanation: Zinc oxide is amphoteric because it reacts with both acids (e.g., sulfuric acid) and bases (e.g., sodium hydroxide) to form salts and water.
Question 21 (Sub-topic – C8.4)
Some properties of different metals are shown. Which metals are transition elements?
| density g/cm³ | melting point/°C | colour of compound formed by the metal | |
|---|---|---|---|
| 1 | 1.54 | 851 | white |
| 2 | 8.91 | 1455 | green |
| 3 | 5.80 | 1890 | lilac |
| 4 | 11.3 | 328 | white |
A) 1 and 2
B) 1 and 4
C) 2 and 3
D) 3 and 4
▶️Answer/Explanation
Answer: C) 2 and 3
Explanation: Transition elements typically have high densities, high melting points, and form coloured compounds. Metals 2 and 3 fit these criteria, with high melting points and coloured compounds (green and lilac).
Question 22 (Sub-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) to increase the hardness of the steel
Explanation: Manganese is added to steel to increase its hardness and strength, making it suitable for tools like drills that require durability.
Question 23 (Sub-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) Zinc prevents oxygen from reaching the steel.
Explanation: Sacrificial protection works because zinc is more reactive than iron and oxidises instead of the iron. It does not prevent oxygen from reaching the steel but sacrifices itself to protect the steel.
Question 24 (Sub-topic – C10.1)
Ammonia is manufactured by the Haber process from nitrogen and hydrogen. What is the source of hydrogen for this process?
A) the electrolysis of dilute sulfuric acid
B) the fractional distillation of liquid air
C) the reaction of an acid with a reactive metal
D) the reaction of steam with natural gas
▶️Answer/Explanation
Answer: D) the reaction of steam with natural gas
Explanation: In the Haber process, hydrogen is typically obtained from the reaction of steam with natural gas (methane), producing hydrogen and carbon dioxide.
Question 25 (Sub-topic – C10.2)
Sulfuric acid is manufactured by the Contact process. Which reaction in this process uses a catalyst?
A) \( \text{S} + \text{O}_2 \rightarrow \text{SO}_2 \)
B) \( 2\text{SO}_2 + \text{O}_2 \rightarrow 2\text{SO}_3 \)
C) \( \text{SO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{H}_2\text{S}_2\text{O}_7 \)
D) \( \text{H}_2\text{S}_2\text{O}_7 + \text{H}_2\text{O} \rightarrow 2\text{H}_2\text{SO}_4 \)
▶️Answer/Explanation
Answer: B) \( 2\text{SO}_2 + \text{O}_2 \rightarrow 2\text{SO}_3 \)
Explanation: In the Contact process, the reaction between sulfur dioxide and oxygen to form sulfur trioxide (\( \text{SO}_3 \)) uses a vanadium(V) oxide catalyst.
Question 26 (Sub-topic – C10.2)
Which compound is used to neutralise acidic gases?
A) calcium carbonate
B) calcium chloride
C) calcium phosphate
D) calcium sulfate
▶️Answer/Explanation
Answer: A) calcium carbonate
Explanation: Calcium carbonate is commonly used to neutralise acidic gases, such as sulfur dioxide, in processes like flue gas desulfurisation.
Question 27 (Sub-topic – C11.2)
Four molecules are shown. Which structure represents ethanol?
A) \( \text{CH}_3\text{CH}_2\text{OH} \)
B) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{OH} \)
C) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{OH} \)
D) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_2\text{OH} \)
▶️Answer/Explanation
Answer: A) \( \text{CH}_3\text{CH}_2\text{OH} \)
Explanation: Ethanol has the molecular formula \( \text{C}_2\text{H}_5\text{OH} \), which corresponds to \( \text{CH}_3\text{CH}_2\text{OH} \).
Question 28 (Sub-topic – P1.5.1)
A rubber band and a copper wire are each stretched by hanging a load on one end. At first, both obey Hooke’s Law. When the rubber band reaches its limit of proportionality, it becomes more difficult to stretch. When the copper wire reaches its limit of proportionality, it becomes easier to stretch. Which two graphs are the extension–load graphs for the rubber band and the copper wire?
A) graph 1 (rubber band), graph 3 (copper wire)
B) graph 2 (rubber band), graph 4 (copper wire)
C) graph 3 (rubber band), graph 1 (copper wire)
D) graph 4 (rubber band), graph 2 (copper wire)
▶️Answer/Explanation
Answer: B) graph 2 (rubber band), graph 4 (copper wire)
Explanation: The rubber band becomes harder to stretch beyond its limit of proportionality, resulting in a steeper graph (graph 2). The copper wire becomes easier to stretch, resulting in a less steep graph (graph 4).
Question 29 (Sub-topic – P1.5.2)
What is meant by the moment of a force?
A) the speed of an object moved by a force
B) the time taken for a force to move an object
C) the turning effect of a force
D) the work done by a force
▶️Answer/Explanation
Answer: C) the turning effect of a force
Explanation: The moment of a force is the turning effect of the force, calculated as the product of the force and the perpendicular distance from the pivot.
Question 30 (Sub-topic – P1.7)
What cannot be used as a unit for pressure?
A) N/m²
B) N/cm²
C) Pa
D) Pa/m²
▶️Answer/Explanation
Answer: D) Pa/m²
Explanation: Pressure is defined as force per unit area, so its units are N/m² or Pa. Pa/m² is not a valid unit for pressure.
Question 31 (Sub-topic – P1.6.1)
A stone falls from a bench. Which row describes how the gravitational potential energy and the kinetic energy of the stone change as it falls?
| gravitational potential energy | kinetic energy | |
|---|---|---|
| A | decreases | increases |
| B | decreases | stays the same |
| C | increases | decreases |
| D | increases | stays the same |
▶️Answer/Explanation
Answer: A) decreases, increases
Explanation: As the stone falls, its height decreases, reducing its gravitational potential energy. At the same time, its speed increases, increasing its kinetic energy.
Question 32 (Sub-topic – P1.6.4)
A lamp transfers 20 J of electrical energy into 12 J of useful light energy. What is the efficiency of the lamp?
A) 33%
B) 40%
C) 60%
D) 66%
▶️Answer/Explanation
Answer: C) 60%
Explanation: Efficiency is calculated as (useful energy output / total energy input) × 100%. Here, it is (12 J / 20 J) × 100% = 60%.
Question 33 (Sub-topic – P2.1.1)
Which labelled arrow on the diagram represents condensation?
A) A
B) B
C) C
D) D
▶️Answer/Explanation
Answer: A) A
Explanation: Condensation is the process where a gas turns into a liquid. In the diagram, arrow A represents this phase change.
Question 34 (Sub-topic – P2.2.2)
The diagrams show four liquid-in-glass thermometers, all drawn to the same scale. Which thermometer has the greatest sensitivity?
A) A
B) B
C) C
D) D
▶️Answer/Explanation
Answer: B) B
Explanation: Sensitivity refers to the ability of a thermometer to detect small changes in temperature. Thermometer B has the smallest divisions, indicating the greatest sensitivity.
Question 35 (Sub-topic – P3.2.1)
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) 70°
Explanation: The angle of reflection is equal to the angle of incidence. If the angle of incidence is 70°, the angle of reflection is also 70°.
Question 36 (Sub-topic – P3.2.2)
Light is travelling in a glass block. The light reaches the edge of the block. The angle of incidence at the edge is much less than the critical angle. What happens to the light?
A) All of the light emerges into the air.
B) All of the light is reflected back into the block.
C) Some of the light emerges into the air and some is reflected back into the block.
D) Some of the light is reflected back into the block and some travels along the edge of the block.
▶️Answer/Explanation
Answer: C) Some of the light emerges into the air and some is reflected back into the block.
Explanation: When the angle of incidence is less than the critical angle, some light is refracted out of the block into the air, and some is reflected back into the block.
Question 37 (Sub-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?
| type of wave | direction of vibration | |
|---|---|---|
| A | longitudinal | parallel to wave direction |
| B | longitudinal | perpendicular to wave direction |
| C | transverse | parallel to wave direction |
| D | transverse | perpendicular to wave direction |
▶️Answer/Explanation
Answer: A) longitudinal, parallel to wave direction
Explanation: In a longitudinal wave, such as a sound wave in air, the molecules vibrate parallel to the direction of wave propagation, creating regions of compression (P) and rarefaction (Q).
Question 38 (Sub-topic – P4.1)
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) The rod is a positively charged electrical insulator.
Explanation: The negatively charged 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 must be an insulator.
Question 39 (Sub-topic – P4.5.4)
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) 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. The force acts in direction B.
Question 40 (Sub-topic – P5.2.3)
The nuclide \(^{14}_{6}C\) decays into the nuclide \(^{14}_{7}N\) by emitting a \(\beta\)-particle. Which equation shows this decay?
A) \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{0}_{-1}\beta\)
B) \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{0}_{1}\beta\)
C) \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{4}_{2}\beta\)
D) \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{4}_{-2}\beta\)
▶️Answer/Explanation
Answer: A) \(^{14}_{6}C \rightarrow ^{14}_{7}N + ^{0}_{-1}\beta\)
Explanation: In beta decay, a neutron in the nucleus is converted into a proton, emitting a beta particle (electron) and an antineutrino. The atomic number increases by 1, while the mass number remains the same.