Question 1 (Subtopic: B12.1 Respiration)
What is respiration?
A. breakdown of food by enzymes in the alimentary canal
B. breathing to supply oxygen to cells
C. release of carbon dioxide from the lungs
D. release of energy for body activities
▶️Answer/Explanation
Answer: D
Explanation: Respiration is the process by which cells break down glucose to release energy for body activities. This process occurs in the mitochondria of cells and involves the production of ATP (adenosine triphosphate), which is used as energy by the body.
Question 2 (Subtopic: B11.1 Gas exchange in humans)
Which diagram correctly shows the diffusion of carbon dioxide and oxygen between an alveolus and a capillary?
▶️Answer/Explanation
Answer: C
Explanation: Diagram C correctly shows the diffusion of oxygen from the alveolus into the capillary and carbon dioxide from the capillary into the alveolus. This is because oxygen moves from an area of high concentration (alveolus) to an area of low concentration (capillary), and carbon dioxide moves in the opposite direction.
Question 3 (Subtopic: B4.1 Biological molecules)
Which row matches the nutrient to the chemical elements that it contains?
▶️Answer/Explanation
Answer: B
Explanation: Proteins are made up of amino acids, which contain carbon, hydrogen, oxygen, and nitrogen. Fats contain carbon, hydrogen, and oxygen, while starch and sugars are carbohydrates that contain carbon, hydrogen, and oxygen but no nitrogen.
Question 4 (Subtopic: B5.1 Enzymes)
Which type of molecule are enzymes?
A. Fat
B. Carbohydrate
C. Protein
D. DNA
▶️Answer/Explanation
Answer: C
Explanation: Enzymes are biological catalysts made up of proteins. They speed up chemical reactions in the body without being consumed in the process.
Question 5 (Subtopic: B6.1 Photosynthesis)
Four test-tubes were set up as shown. Which test-tube will contain the most dissolved oxygen after 24 hours?
▶️Answer/Explanation
Answer: A
Explanation: Test-tube A will contain the most dissolved oxygen because it is exposed to light, which allows photosynthesis to occur, producing oxygen. The other test-tubes either lack light or have organisms that consume oxygen, reducing the amount of dissolved oxygen.
Question 6 (Subtopic: B7.2 Digestive system)
The diagram shows the human digestive system.
Where do digestion, egestion, ingestion, and absorption take place?
▶️Answer/Explanation
Answer: B
Explanation: Digestion occurs in the stomach (2), egestion occurs in the large intestine (4), ingestion occurs in the mouth (1), and absorption occurs in the small intestine (3).
Question 7 (Subtopic: B8.3 Transpiration)
Transpiration is the process by which water moves through a plant. From which cells in the leaf does most of the water evaporate and through which structure is it lost as water vapour to the atmosphere?
▶️Answer/Explanation
Answer: D
Explanation: Most of the water evaporates from the mesophyll cells in the leaf and is lost as water vapour through the stomata, which are small openings on the underside of the leaf.
Question 8 (Subtopic: B11.1 Gas exchange in humans)
A child blows into a rubber balloon. What is the percentage of oxygen inside the balloon?
A. 0%
B. 4%
C. 16%
D. 21%
▶️Answer/Explanation
Answer: C
Explanation: When a child blows into a balloon, the air inside is exhaled air, which contains about 16% oxygen, as some oxygen is absorbed by the body during respiration.
Question 9 (Subtopic: B13.2)
A student is in a dangerous situation and adrenaline is released into the blood. The table shows changes to pulse rate, breathing rate, and pupil diameter.
Which row correctly describes the effect of adrenaline?
▶️Answer/Explanation
Answer: C
Explanation: Adrenaline increases the pulse rate, breathing rate, and pupil diameter as part of the “fight or flight” response to prepare the body for action.
Question 10 (Subtopic: B15.4)
The diagram shows the human male reproductive system.
What are the functions of X and Y?
▶️Answer/Explanation
Answer: A
Explanation: X is the urethra, which carries both urine and semen out of the body. Y is the vas deferens, which transfers sperm to the urethra.
Question 11 (Subtopic: B16.1)
Which row is correct for the inheritance of sex in humans?
▶️Answer/Explanation
Answer: A
Explanation: In humans, females have two X chromosomes (XX), and males have one X and one Y chromosome (XY). This determines the inheritance of sex.
Question 12 (Subtopic: B18.2)
Dung beetles lay their eggs in the faeces of plant-eating mammals like buffalo. Both the adult beetles and their young stages eat the undigested food in the faeces. Which diagram shows this food relationship?
▶️Answer/Explanation
Answer: D
Explanation: The correct food relationship is grass (producer) → buffalo (primary consumer) → dung beetles (secondary consumer). The dung beetles feed on the undigested food in the buffalo’s faeces.
Question 13 (Subtopic: B6.1)
Which process removes carbon dioxide from the atmosphere?
A. combustion
B. photosynthesis
C. respiration
D. transpiration
▶️Answer/Explanation
Answer: B
Explanation: Photosynthesis is the process by which plants remove carbon dioxide from the atmosphere and convert it into glucose and oxygen using sunlight.
Question 14 (Subtopic: C2.2)
The structures of some substances are shown.
Which row shows the total number of different elements and the total number of atoms in the three structures?
| Total number of different elements | Total number of atoms |
|---|---|
| A. 3 | 9 |
| B. 3 | 17 |
| C. 7 | 9 |
| D. 7 | 17 |
▶️Answer/Explanation
Answer: B
Explanation: The three substances (water, ethanol, and methane) contain a total of 3 different elements (hydrogen, oxygen, and carbon) and 17 atoms in total (H₂O: 3 atoms, C₂H₅OH: 9 atoms, CH₄: 5 atoms).
Question 15 (Subtopic: C12.4 Separation and purification)
Which method can be used to separate graphite from dilute nitric acid?
A. Chromatography
B. Crystallisation
C. Distillation
D. Filtration
▶️Answer/Explanation
Answer: D
Explanation: Filtration is used to separate insoluble solids (like graphite) from liquids (like dilute nitric acid). The solid remains on the filter paper, while the liquid passes through.
Question 16 (Subtopic: C2.5 Simple molecules and covalent bonds)
Which statement about a carbon dioxide molecule is correct?
A. It is composed of metallic elements, which are covalently bonded.
B. It is composed of metallic elements, which are ionically bonded.
C. It is composed of non-metallic elements, which are covalently bonded.
D. It is composed of non-metallic elements, which are ionically bonded.
▶️Answer/Explanation
Answer: C
Explanation: Carbon dioxide (CO₂) is composed of non-metallic elements (carbon and oxygen) that are covalently bonded, meaning they share electrons.
Question 17 (Subtopic: C5.1)
Hydrogen reacts with iodine to form hydrogen iodide. The equation for this reaction is shown.
\(H_{2}\) + \(I_{2}\) → 2HI
During this reaction, the temperature increases.
Which statement explains why the temperature increases?
A. One molecule of hydrogen is forming two molecules of hydrogen iodide.
B. The reaction is exothermic.
C. The reaction is very fast.
D. The reaction takes in energy.
▶️Answer/Explanation
Answer: B
Explanation: The temperature increases because the reaction is exothermic, meaning it releases energy in the form of heat.
Question 18 (Subtopic: C6.3)
The catalytic converter in the exhaust of a car brings about the reaction shown.
2NO + 2CO → \(2CO_{2}\) + \(N_{2}\)
Which row about this reaction is correct?
| Oxidation | Reduction |
|---|---|
| A. ✓ | ✓ |
| B. ✓ | ✗ |
| C. ✗ | ✓ |
| D. ✗ | ✗ |
▶️Answer/Explanation
Answer: A
Explanation: In the catalytic converter, carbon monoxide (CO) is oxidized to carbon dioxide (CO₂), and nitrogen oxides (NO) are reduced to nitrogen (N₂). Therefore, both oxidation and reduction occur.
Question 19 (Subtopic: C12.5)
The results of two tests on substance X are listed.
1. A lilac flame is produced in a flame test.
2. A gas which turns damp red litmus blue is produced when X is heated with aluminium powder and aqueous sodium hydroxide.
What is X?
A. potassium nitrate
B. potassium sulfate
C. sodium nitrate
D. sodium sulfate
▶️Answer/Explanation
Answer: A
Explanation: The lilac flame indicates the presence of potassium, and the gas that turns damp red litmus blue is ammonia, which is produced when nitrates are heated with aluminium powder and sodium hydroxide. Therefore, X is potassium nitrate.
Question 20 (Subtopic: C7.1)
What reacts with ammonia gas?
| Hydrochloric acid | Sodium hydroxide |
|---|---|
| A. ✓ | ✓ |
| B. ✓ | ✗ |
| C. ✗ | ✓ |
| D. ✗ | ✗ |
▶️Answer/Explanation
Answer: B
Explanation: Ammonia gas reacts with hydrochloric acid to form ammonium chloride, but it does not react with sodium hydroxide.
Question 21 (Subtopic: C8.2)
Which row describes trends in the properties of Group I elements as the group is descended?
| Melting point | Reactivity with water |
|---|---|
| A. decreasing | decreasing |
| B. decreasing | increasing |
| C. increasing | decreasing |
| D. increasing | increasing |
▶️Answer/Explanation
Answer: B
Explanation: As you go down Group I (alkali metals), the melting point decreases, and the reactivity with water increases. This is because the outer electron is further from the nucleus and less strongly attracted, making it easier to lose.
Question 22 (Subtopic: C9.6 Extraction of metals)
Bauxite is the main ore of aluminium. Which method is used to extract pure aluminium from bauxite?
A. Fractional distillation
B. Electrolysis
C. Neutralisation
D. Thermal decomposition
▶️Answer/Explanation
Answer: B
Explanation: Aluminium is extracted from bauxite using electrolysis. This process involves passing an electric current through molten aluminium oxide to separate the aluminium metal.
Question 23 (Subtopic: C10.1 Water)
In order to make water from reservoirs fit to drink, ……1…… is used to kill bacteria. Water in a condenser is used during distillation as a ……2…… . When water is used to make ethanol from ethene, it is acting as a ……3…… . Which words correctly complete gaps 1, 2, and 3?
A. Chlorination, coolant, reactant
B. Chlorination, solvent, solvent
C. Filtration, coolant, reactant
D. Filtration, solvent, solvent
▶️Answer/Explanation
Answer: A
Explanation: Chlorination is used to kill bacteria in water. In distillation, water acts as a coolant in the condenser. When making ethanol from ethene, water acts as a reactant.
Question 24 (Subtopic: C10.1 Water)
Other than hydrogen and oxygen, which substance provides only one of the essential elements for plant growth?
A. K₃PO₄
B. KNO₃
C. (NH₄)₃PO₄
D. NH₄NO₃
▶️Answer/Explanation
Answer: D
Explanation: NH₄NO₃ (ammonium nitrate) provides only nitrogen, which is one of the essential elements for plant growth. The other substances provide multiple elements.
Question 25 (Subtopic: C9.6 Extraction of metals)
What are the products of the thermal decomposition of calcium carbonate, CaCO₃?
A. Calcium and carbon dioxide
B. Calcium, carbon, and oxygen
C. Calcium oxide and carbon dioxide
D. Calcium oxide and carbon monoxide
▶️Answer/Explanation
Answer: C
Explanation: When calcium carbonate is heated, it decomposes into calcium oxide (CaO) and carbon dioxide (CO₂).
Question 26 (Subtopic: C11.3 Fuels)
Which property allows petroleum to be separated by fractional distillation?
A. Boiling point
B. Colour
C. Density
D. Melting point
▶️Answer/Explanation
Answer: A
Explanation: Petroleum is separated by fractional distillation based on the different boiling points of its components. Each fraction condenses at a different temperature.
Question 27 (Subtopic: C11.7)
Poly(ethene) is a saturated hydrocarbon. It is formed by the addition polymerisation of ethene, H₂C=CH₂. Which diagram shows part of a molecule of poly(ethene)?
▶️Answer/Explanation
Answer: D
Explanation: Poly(ethene) is formed by the addition polymerisation of ethene, resulting in a long chain of -CH₂-CH₂- units. The correct structure is -CH₂-CH₂-CH₂-CH₂-.
Question 28 (Subtopic: P1.2 Motion)
A girl runs 5000 m in 1200 seconds and then walks a further 3000 m in 1800 seconds. What is her average speed for this journey?
A. 1.7 m/s
B. 2.7 m/s
C. 2.9 m/s
D. 5.8 m/s
▶️Answer/Explanation
Answer: B
Explanation: The total distance is 5000 m + 3000 m = 8000 m. The total time is 1200 s + 1800 s = 3000 s. Average speed = total distance / total time = 8000 m / 3000 s = 2.7 m/s.
Question 29 (Subtopic: P1.2 Motion)
An object is falling freely near the Earth without air resistance. Which statement about the acceleration of the object is correct?
A. It is constant, but not zero.
B. It is decreasing.
C. It is increasing.
D. It is zero.
▶️Answer/Explanation
Answer: A
Explanation: In free fall near the Earth, the acceleration due to gravity is constant at approximately 9.8 m/s², assuming no air resistance.
Question 30 (Subtopic: P1.5.3)
Three objects X, Y, and Z are at rest on a table. The centre of mass of each object is labelled M.
What is the order of stability of these three objects, from most stable to least stable?
A. X → Y → Z
B. Y → Z → X
C. X → Z → Y
D. Z → Y → X
▶️Answer/Explanation
Answer: D
Explanation: The stability of an object depends on the position of its centre of mass. The lower the centre of mass, the more stable the object. Therefore, Z (lowest centre of mass) is the most stable, followed by Y, and then X (least stable).
Question 31 (Subtopic: P1.6.1)
The diagram shows a man diving into water.
Which form of energy is increasing as he accelerates downwards through the air?
A. chemical
B. elastic potential (strain)
C. gravitational potential
D. kinetic
▶️Answer/Explanation
Answer: D
Explanation: As the man accelerates downwards, his speed increases, which means his kinetic energy (energy of motion) is increasing. Gravitational potential energy decreases as he falls.
Question 32 (Subtopic: P2.3 Transfer of thermal energy)
There is a vacuum between the double walls of a vacuum flask. Which of the methods of thermal energy transfer are prevented by the vacuum?
A. Conduction only
B. Conduction and convection
C. Convection only
D. Radiation only
▶️Answer/Explanation
Answer: B
Explanation: A vacuum prevents both conduction and convection because there are no particles to transfer heat. However, radiation can still occur through a vacuum.
Question 33 (Subtopic: P3.2.1 Reflection of light)
A boy looks into a plane mirror that is 50 cm in front of his face. How far from the boy’s face is the image of his face?
A. 25 cm
B. 50 cm
C. 100 cm
D. 150 cm
▶️Answer/Explanation
Answer: C
Explanation: In a plane mirror, the image distance is equal to the object distance. Since the mirror is 50 cm in front of the boy, the image is 50 cm behind the mirror, making the total distance 100 cm.
Question 34 (Subtopic: P3.2.3)
The diagram shows the image of an object produced by a thin converging lens.
How is the image described?
A. diminished and inverted
B. diminished and upright
C. enlarged and inverted
D. enlarged and upright
▶️Answer/Explanation
Answer: C
Explanation: A thin converging lens produces an enlarged and inverted image when the object is placed between the focal point and twice the focal length of the lens.
Question 35 (Subtopic: P3.1)
Sound from a loudspeaker at P travels directly to Q. Sound also reaches Q after being reflected from a wall at R.
The speed of sound is 330 m/s.
What is the difference in time for sound to travel from P to Q by the two routes?
A. 6/330 s
B. 16/330 s
C. 6 × 330 s
D. 16 × 330 s
▶️Answer/Explanation
Answer: A
Explanation: The difference in time is calculated by dividing the extra distance traveled by the speed of sound. If the extra distance is 6 m, the time difference is 6/330 s.
Question 36 (Subtopic: P4.3.1)
Which circuit can be used to take measurements to determine the resistance of resistor R?
▶️Answer/Explanation
Answer: D
Explanation: To measure resistance, the voltmeter must be connected in parallel across the resistor to measure the voltage, and the ammeter must be connected in series to measure the current. Ohm’s Law (R = V/I) can then be used to calculate the resistance.
Question 37 (Subtopic: P4.3.1)
In which circuit can the brightness of the lamp be varied continuously?
▶️Answer/Explanation
Answer: A
Explanation: A variable resistor (rheostat) allows the current in the circuit to be adjusted, which in turn varies the brightness of the lamp continuously.
Question 38 (Subtopic: P4.4)
A student connects the circuit shown.
When the switch is closed, the fuse blows and stops the current.
What is a possible reason for this?
A. The current rating of the fuse is too high.
B. The current is too large.
C. The lamp is too dim.
D. The voltage is too small.
▶️Answer/Explanation
Answer: B
Explanation: If the current in the circuit exceeds the rating of the fuse, the fuse will blow to protect the circuit. This indicates that the current is too large.
Question 39 (Subtopic: P4.5.4)
The diagram shows a wire in a magnetic field. There is a current in the wire.
The force produced on the wire causes the wire to move into the page. The direction of the current is now reversed.
What happens to the wire?
A. It does not move at all.
B. It moves out of the page.
C. It moves sideways towards one of the poles of the magnet.
D. It still moves into the page.
▶️Answer/Explanation
Answer: B
Explanation: Reversing the direction of the current reverses the direction of the force acting on the wire. If the wire initially moved into the page, it will now move out of the page.
Question 40 (Subtopic: P5.2.3 Radioactive decay)
A radioactive nucleus emits a β-particle. What happens to the proton number (atomic number) of the nucleus?
A. It stays the same.
B. It increases by 1.
C. It decreases by 2.
D. It decreases by 4.
▶️Answer/Explanation
Answer: B
Explanation: When a nucleus emits a β-particle (an electron), a neutron is converted into a proton, increasing the proton number by 1.