Question 1 (Subtopic: B1.1)
Which statement defines excretion?
A. the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
B. the removal from organisms of the waste products of metabolism
C. the taking in of materials for energy, growth and development
D. the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
▶️Answer/Explanation
Answer: B
Explanation: Excretion is the process by which waste products of metabolism are removed from the body. This includes substances like carbon dioxide, urea, and excess water. Option B correctly defines excretion, while the other options describe different biological processes such as respiration (A), nutrition (C), and sensitivity (D).
Question 2 (Subtopic: B2.1)
The diagram shows an incomplete plant cell.
Which structure is not shown?
A. cell membrane
B. cell wall
C. chloroplast
D. vacuole
▶️Answer/Explanation
Answer: B
Explanation: The cell wall is a rigid structure that surrounds the cell membrane in plant cells, providing support and protection. In the diagram, if the cell wall is not shown, it means the cell membrane, chloroplast, and vacuole are visible. Therefore, the structure not shown is the cell wall (B).
Question 3 (Subtopic: B4.1)
What are the molecules that make up fats and oils?
A. amino acids and glycerol
B. fatty acids and glycerol
C. glucose and amino acids
D. glucose and fatty acids
▶️Answer/Explanation
Answer: B
Explanation: Fats and oils are composed of fatty acids and glycerol. These molecules combine to form triglycerides, which are the main constituents of fats and oils. Amino acids are the building blocks of proteins, and glucose is a simple sugar, so options A, C, and D are incorrect.
Question 4 (Subtopic: B5.1)
What are biological catalysts?
A. antibodies
B. enzymes
C. hormones
D. platelets
▶️Answer/Explanation
Answer: B
Explanation: Biological catalysts are enzymes, which speed up chemical reactions in living organisms without being consumed in the process. Antibodies are part of the immune system, hormones are chemical messengers, and platelets are involved in blood clotting, so options A, C, and D are incorrect.
Question 5 (Subtopic: B6.1)
Which graph shows the effect of increasing light intensity on the rate of photosynthesis?
▶️Answer/Explanation
Answer: C
Explanation: The rate of photosynthesis increases with light intensity up to a certain point, after which it plateaus due to other limiting factors such as carbon dioxide concentration or temperature. Graph C correctly shows this relationship, where the rate of photosynthesis increases linearly with light intensity and then levels off.
Question 6 (Subtopic: B7.2)
The diagram shows part of the alimentary canal and associated organs.
Where is lipase produced?
▶️Answer/Explanation
Answer: A
Explanation: Lipase is an enzyme that breaks down fats into fatty acids and glycerol. It is produced in the pancreas and secreted into the small intestine, where it acts on dietary fats. The stomach produces pepsin, the small intestine produces various enzymes, and the liver produces bile, so options B, C, and D are incorrect.
Question 7 (Subtopic: B8.3)
In which weather conditions is the rate of transpiration fastest?
A. cold and dry
B. cold and wet
C. warm and dry
D. warm and wet
▶️Answer/Explanation
Answer: C
Explanation: Transpiration is the process by which water is lost from plants through evaporation. It is fastest in warm and dry conditions because higher temperatures increase the rate of evaporation, and dry air increases the water potential gradient between the leaf and the atmosphere, driving more water loss.
Question 8 (Subtopic: B11.1)
When a person was walking or running, the following measurements were taken:
| Speed (km/h) | Number of breaths per minute | Volume of each breath (dm³) |
|---|---|---|
| 4 | 16 | 1 |
| 6 | 18 | 2 |
| 8 | 20 | 3 |
How many dm³ of air did the person breathe per minute when running at 6 km per hour?
A. 18
B. 36
C. 60
D. 108
▶️Answer/Explanation
Answer: B
Explanation: To calculate the total volume of air breathed per minute, multiply the number of breaths per minute by the volume of each breath. At 6 km/h, the person takes 18 breaths per minute, and each breath is 2 dm³. Therefore, the total volume is 18 × 2 = 36 dm³.
Question 9 (Subtopic: B13.1)
The diagram shows structures in a section through the front of the eye.
When reading a book, how are the labelled structures involved in focusing the eye?
| 1 | 2 | 3 | |
|---|---|---|---|
| A | contracts | thicker | slackens |
| B | contracts | thinner | tightens |
| C | relaxes | thicker | tightens |
| D | relaxes | thinner | slackens |
▶️Answer/Explanation
Answer: A
Explanation: When reading a book, the ciliary muscles (structure 1) contract, causing the suspensory ligaments (structure 3) to slacken. This allows the lens (structure 2) to become thicker and more convex, increasing its refractive power to focus on nearby objects.
Question 10 (Subtopic: B15.3)
Which features are adaptations of wind-pollinated flowers?
1. anthers exposed to the wind
2. produce heavy sticky pollen
3. produce large quantities of pollen
4. brightly coloured petals
5. produce nectar
A. 1, 2 and 3
B. 3, 4 and 5
C. 1 and 3 only
D. 4 and 5 only
▶️Answer/Explanation
Answer: C
Explanation: Wind-pollinated flowers have adaptations such as exposed anthers to release pollen into the wind and produce large quantities of pollen to increase the chances of pollination. They do not produce heavy sticky pollen, brightly coloured petals, or nectar, as these are adaptations for insect-pollinated flowers.
Question 11 (Subtopic – B17.2)
Selective breeding is used to improve crop plants. What does it involve?
A. artificial selection
B. asexual reproduction
C. ionising radiation
D. natural selection
▶️Answer/Explanation
Answer: A. artificial selection
Explanation: Selective breeding involves the intentional selection of plants or animals with desirable traits to produce offspring with those traits. This process is also known as artificial selection, as it is controlled by humans rather than occurring naturally.
Question 12 (Subtopic – B18.2)
The diagram shows a food web.
How many organisms act as secondary consumers in this food web?
A. 2
B. 3
C. 4
D. 6
▶️Answer/Explanation
Answer: C. 4
Explanation: Secondary consumers are organisms that feed on primary consumers. In the given food web, the secondary consumers are the fox, snake, lizard, and hawk. Therefore, there are 4 secondary consumers.
Question 13 (Subtopic – B19.1)
The graph shows changes during eutrophication.
What could be the label for the vertical (y) axis?
1. growth of producers
2. number of aerobic bacteria
3. rate of decomposition
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: During eutrophication, the growth of producers (algae and plants) increases, leading to an increase in the number of aerobic bacteria and the rate of decomposition as organic matter accumulates. Therefore, all three labels could be correct for the vertical axis.
Question 14 (Subtopic – C12.3)
Which process is used to separate a mixture of coloured compounds?
A. chromatography
B. distillation
C. evaporation
D. filtration
▶️Answer/Explanation
Answer: A. chromatography
Explanation: Chromatography is a technique used to separate mixtures of coloured compounds based on their different solubilities in a solvent. The compounds move at different rates, allowing them to be separated.
Question 15 (Subtopic – C2.3)
The electronic structures of four isotopes are shown.
Which isotopes have the same chemical properties?
A. 1 and 3
B. 1 and 4
C. 2 and 3
D. 2 and 4
▶️Answer/Explanation
Answer: A. 1 and 3
Explanation: Isotopes of the same element have the same number of protons and electrons, which means they have the same electronic structure and thus the same chemical properties. Therefore, isotopes 1 and 3, which are isotopes of the same element, have the same chemical properties.
Question 16 (Subtopic – C3.2)
What is the mass of hydrogen in 51 g of ammonia, NH₃?
A. 3 g
B. 9 g
C. 14 g
D. 17 g
▶️Answer/Explanation
Answer: B. 9 g
Explanation: The molar mass of NH₃ is 17 g/mol (14 g/mol for nitrogen and 3 g/mol for hydrogen). In 51 g of NH₃, there are 3 moles of NH₃. Since each mole of NH₃ contains 3 g of hydrogen, the total mass of hydrogen in 51 g of NH₃ is 9 g.
Question 17 (Subtopic – C4.1)
Molten lead(II) bromide is electrolysed.
Which equation represents the reaction at the cathode?
A. 2Br⁻ → Br₂ + 2e⁻
B. Br₂ + 2e⁻ → 2Br⁻
C. Pb²⁺ → Pb + 2e⁻
D. Pb²⁺ + 2e⁻ → Pb
▶️Answer/Explanation
Answer: D. Pb²⁺ + 2e⁻ → Pb
Explanation: During the electrolysis of molten lead(II) bromide, lead ions (Pb²⁺) are reduced at the cathode to form lead metal. The correct equation for this reduction reaction is Pb²⁺ + 2e⁻ → Pb.
Question 18 (Subtopic – C5.1)
The diagram shows the energy change for the reactions between hydrogen and the halogens.
The reaction is \(H_{₂}\) + \(X_{₂}\) → 2HX.
The size of the energy change is different for each halogen.
The diagram shows that the reactions are ……1……. The most reactive halogen is ……2…… and therefore the energy change for this element is ……3…….
Which words complete gaps 1, 2 and 3?
A. endothermic, fluorine, least
B. endothermic, iodine, least
C. exothermic, fluorine, greatest
D. exothermic, iodine, greatest
▶️Answer/Explanation
Answer: C. exothermic, fluorine, greatest
Explanation: The reactions between hydrogen and halogens are exothermic, meaning they release energy. Fluorine is the most reactive halogen, and the energy change for its reaction with hydrogen is the greatest because it releases the most energy.
Question 19 (Subtopic – C6.3)
In which equation is the underlined substance acting as an oxidising agent?
A. CuO + H₂ → Cu + H₂O
B. CuSO₄ + Mg → MgSO₄ + Cu
C. H₂ + Cl₂ → 2HCl
D. Zn + 2HCl → ZnCl₂ + H₂
▶️Answer/Explanation
Answer: C. H₂ + Cl₂ → 2HCl
Explanation: In the reaction H₂ + Cl₂ → 2HCl, chlorine (Cl₂) is acting as an oxidising agent because it gains electrons from hydrogen, causing hydrogen to be oxidised.
Question 20 (Subtopic – C7.1)
A label from a packet of indigestion tablets is shown.
Which substance does not neutralise stomach acid?
A. magnesium carbonate
B. magnesium hydroxide
C. magnesium oxide
D. magnesium sulfate
▶️Answer/Explanation
Answer: D. magnesium sulfate
Explanation: Magnesium sulfate does not neutralise stomach acid because it is a salt and does not react with acids. The other substances (magnesium carbonate, magnesium hydroxide, and magnesium oxide) are bases that can neutralise stomach acid.
Question 21 (Subtopic – C7.3)
Substance X is insoluble in water.
It reacts with dilute nitric acid to produce solution Y and a gas which turns limewater milky.
A white precipitate is formed when aqueous sodium hydroxide is added to solution Y. This precipitate remains when excess sodium hydroxide is added.
What is substance X?
A calcium carbonate
B calcium chloride
C zinc carbonate
D zinc chloride
▶️Answer/Explanation
Answer: A calcium carbonate
Explanation: Calcium carbonate (CaCO₃) is insoluble in water and reacts with dilute nitric acid to produce calcium nitrate (solution Y) and carbon dioxide gas, which turns limewater milky. When aqueous sodium hydroxide is added to solution Y, a white precipitate of calcium hydroxide forms, which remains even when excess sodium hydroxide is added.
Question 22 (Sub-topic – C8.3)
Astatine is below iodine in Group VII of the Periodic Table. Which statements about astatine are correct?
1 It is monoatomic.
2 It is a solid at room temperature.
3 It is lighter in colour than iodine.
4 It does not react with aqueous potassium iodide.
A 1 and 2
B 1 and 3
C 2 and 4
D 3 and 4
▶️Answer/Explanation
Answer: C 2 and 4
Explanation: Astatine is a solid at room temperature and is less reactive than iodine, so it does not react with aqueous potassium iodide. It is not monoatomic (it exists as diatomic molecules like other halogens), and it is darker in color than iodine.
Question 23 (Sub-topic – C8.4)
Which elements in the Periodic Table form coloured compounds?
A Group I metals
B halogens
C noble gases
D transition metals
▶️Answer/Explanation
Answer: D transition metals
Explanation: Transition metals are known for forming colored compounds due to the presence of partially filled d-orbitals, which allow for the absorption of specific wavelengths of light.
Question 24 (Sub-topic – C9.4)
Part of the reactivity series is shown.
aluminium
(carbon)
iron
lead
copper
gold
Which statement is correct?
A Aluminium can be extracted by heating its oxide with carbon.
B Gold forms an oxide which cannot be reduced by heating with aluminium.
C Iron cannot be extracted by heating its oxide with carbon.
D Lead can be extracted by heating its oxide with carbon.
▶️Answer/Explanation
Answer: D Lead can be extracted by heating its oxide with carbon.
Explanation: Lead is below carbon in the reactivity series, so it can be extracted by heating its oxide with carbon. Aluminium is above carbon, so it cannot be extracted by this method. Gold does not form a stable oxide, and iron can be extracted by heating its oxide with carbon.
Question 25 (Sub-topic – C5.1)
Which statement about the Haber process is correct?
A All of the raw materials are obtained from the air.
B It requires a catalyst.
C It uses a low pressure and a high temperature.
D Sulfuric acid is produced in the process.
▶️Answer/Explanation
Answer: B It requires a catalyst.
Explanation: The Haber process synthesizes ammonia from nitrogen and hydrogen using an iron catalyst. It operates at high pressure and moderate temperature, and sulfuric acid is not produced in this process.
Question 26 (Sub-topic – C11.3)
Naphtha is obtained from petroleum. What is a use for naphtha?
A cooking
B making chemicals
C heating
D making roads
▶️Answer/Explanation
Answer: B making chemicals
Explanation: Naphtha is a key feedstock in the petrochemical industry for producing chemicals such as plastics, solvents, and other synthetic materials.
Question 27 (Sub-topic – C11.6)
Ethanol is manufactured by reacting ethene with steam in the presence of a catalyst. Which type of reaction occurs?
A addition
B oxidation
C polymerisation
D reduction
▶️Answer/Explanation
Answer: A addition
Explanation: The reaction between ethene and steam to produce ethanol is an addition reaction, where water (H₂O) adds across the double bond of ethene (C₂H₄).
Question 28 (Sub-topic – P1.4)
A stone of mass 60 g is placed in a measuring cylinder containing water. The water level in the measuring cylinder rises as shown.
What is the density of the stone?
A 0.50 g/cm³
B 0.75 g/cm³
C 1.3 g/cm³
D 2.0 g/cm³
▶️Answer/Explanation
Answer: D 2.0 g/cm³
Explanation: The density of the stone can be calculated using the formula: density = mass/volume. The volume of the stone is equal to the volume of water displaced, which can be determined from the rise in water level in the measuring cylinder.
Question 29 (Sub-topic – P1.5.2)
A scientist uses a lever to lift a heavy load.
She applies a force of 120 N at a distance of 360 cm from a pivot.
What is the moment about the pivot of the force applied by the scientist?
A 3.0 N m
B 33.3 N m
C 432 N m
D 43 200 N m
▶️Answer/Explanation
Answer: C 432 N m
Explanation: The moment (torque) is calculated using the formula: moment = force × distance. Here, the distance must be in meters, so 360 cm = 3.6 m. Thus, moment = 120 N × 3.6 m = 432 N m.
Question 30 (Sub-topic – P1.6.4)
A crane lifts a load of mass 300 kg through a height of 20 m in 1.0 minute. The gravitational field strength \( g \) is 10 N/kg. What is the average power output of the crane during this task?
A 600 W
B 1000 W
C 36 000 W
D 60 000 W
▶️Answer/Explanation
Answer: B 1000 W
Explanation: The work done by the crane is calculated as: work = force × distance = mass × gravitational field strength × height = 300 kg × 10 N/kg × 20 m = 60,000 J. Power is work divided by time, so power = 60,000 J / 60 s = 1000 W.
Question 31 (Subtopic: P1.3)
In a room, hot air above a heater rises and is replaced by cool air that falls. What is the name of this process, and how does the density of the hot air compare with the density of the cool air?
▶️Answer/Explanation
Answer: D
Explanation: The process described is convection, where hot air rises because it is less dense than cool air. As the hot air rises, it is replaced by cooler, denser air that falls. Therefore, the correct answer is D, which states that the process is convection and the density of hot air is less than that of cool air.
Question 32 (Subtopic: P2.1)
A fixed mass of gas is trapped in a cylinder by a piston, as shown. The volume of the gas is increased at constant temperature by moving the piston to the right, as shown.
What effect does this have on the average speed of the molecules and on how many collisions are made by the molecules with the piston each second?
▶️Answer/Explanation
Answer: C
Explanation: When the volume of the gas is increased at constant temperature, the average speed of the gas molecules remains unchanged because temperature is directly related to the average kinetic energy of the molecules. However, the number of collisions with the piston decreases because the molecules are now more spread out, reducing the frequency of collisions. Therefore, the correct answer is C.
Question 33 (Subtopic: P3.2)
The diagram shows two rays of light that have passed from an object through a converging lens.
Which labelled point X or Y is a principal focus of the lens, and how does the size of the image compare with the size of the object?
▶️Answer/Explanation
Answer: A
Explanation: In a converging lens, the principal focus is the point where parallel rays of light converge after passing through the lens. Point X is the principal focus, and the image formed is larger than the object when the object is placed between the focal point and the lens. Therefore, the correct answer is A.
Question 34 (Subtopic: P3.4)
Sound travels at different speeds in water, in steel and in air. Each row in the table gives the three speeds at room temperature. Which row gives the speeds in the correct columns?
▶️Answer/Explanation
Answer: C
Explanation: Sound travels fastest in solids (steel), slower in liquids (water), and slowest in gases (air). Therefore, the correct order of speeds is 1500 m/s (water), 4500 m/s (steel), and 300 m/s (air). The correct answer is C.
Question 35 (Subtopic: P4.1)
What is meant by an electric field?
A. a region in which a charge experiences a force
B. a region in which a current experiences a force
C. a region in which a magnetic pole experiences a force
D. a region in which a mass experiences a force
▶️Answer/Explanation
Answer: A
Explanation: An electric field is a region around a charged particle where another charge experiences a force. Therefore, the correct answer is A.
Question 36 (Subtopic: P4.2)
The electromotive force (e.m.f.) of a battery is 2.0 V. Which statement is correct?
A. The battery supplies 0.50 J of energy for every 1.0 C of charge driven around the circuit.
B. The battery supplies 0.50 J of energy for every 2.0 C of charge driven around the circuit.
C. The battery supplies 2.0 J of energy for every 1.0 C of charge driven around the circuit.
D. The battery supplies 2.0 J of energy for every 2.0 C of charge driven around the circuit.
▶️Answer/Explanation
Answer: C
Explanation: The electromotive force (e.m.f.) is the energy supplied per unit charge. If the e.m.f. is 2.0 V, it means the battery supplies 2.0 J of energy for every 1.0 C of charge. Therefore, the correct answer is C.
Question 37 (Subtopic: P4.5)
Which diagram shows the pattern of the magnetic field due to a current in a straight wire?
▶️Answer/Explanation
Answer: A
Explanation: The magnetic field around a straight current-carrying wire forms concentric circles around the wire. Diagram A correctly represents this pattern. Therefore, the correct answer is A.
Question 38 (Subtopic: P4.5)
Electrical energy from a power station is transmitted over a large distance. A 100% efficient transformer is used near to the power station. This transformer reduces the amount of energy that is wasted thermally in the transmission cables.
How does the transformer reduce the amount of energy that is wasted?
A. It decreases the power transmitted so the current and the voltage are both larger.
B. It decreases the power transmitted so the current and the voltage are both smaller.
C. It increases the current so the voltage is smaller.
D. It increases the voltage so the current is smaller.
▶️Answer/Explanation
Answer: D
Explanation: Transformers are used to increase the voltage and decrease the current for long-distance transmission. This reduces the energy lost as heat in the transmission cables because power loss is proportional to the square of the current (P = I²R). Therefore, the correct answer is D.
Question 39 (Subtopic: P5.1)
The table compares an atom of carbon-13 and an atom of nitrogen-14.
What do the neutral atom of carbon-13 and the neutral atom of nitrogen-14 have the same number of?
A. electrons
B. ions
C. neutrons
D. protons
▶️Answer/Explanation
Answer: C
Explanation: Carbon-13 has 6 protons and 7 neutrons, while nitrogen-14 has 7 protons and 7 neutrons. Both atoms have the same number of neutrons (7). Therefore, the correct answer is C.
Question 40 (Subtopic: P5.2)
α, β and γ radiation can all penetrate materials and ionise atoms.
Which row compares the different types of radiation?
▶️Answer/Explanation
Answer: B
Explanation: α radiation is the least penetrating and most ionising, while γ radiation is the most penetrating and least ionising. Therefore, the correct answer is B, which states that α is the least penetrating and γ is the least ionising.