Question 1 (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 of removing waste products of metabolism from the body. This is essential for maintaining homeostasis and preventing the buildup of harmful substances.
Question 2 (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. If it is not shown in the diagram, it is the missing structure.
Question 3 (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.
Question 4 (B5.1)
What are biological catalysts?
A. antibodies
B. enzymes
C. hormones
D. platelets
▶️Answer/Explanation
Answer: B
Explanation: Enzymes are biological catalysts that speed up chemical reactions in living organisms without being consumed in the process.
Question 5 (B6.1)
Which graph shows the effect of increasing light intensity on the rate of photosynthesis?
▶️Answer/Explanation
Answer: C
Explanation: As light intensity increases, the rate of photosynthesis increases up to a certain point, after which it plateaus. Graph C correctly represents this relationship.
Question 6 (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. It is produced in the pancreas (A) and secreted into the small intestine.
Question 7 (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 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.
Question 8 (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: 18 breaths/min × 2 dm³/breath = 36 dm³/min.
Question 9 (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 focusing on a near object, the ciliary muscles (1) contract, the lens (2) becomes thicker, and the suspensory ligaments (3) slacken to allow the lens to change shape and focus the image on the retina.
Question 10 (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 typically have exposed anthers (1) and produce large quantities of pollen (3) to increase the chances of pollination. They do not usually have brightly coloured petals or produce nectar, as these are adaptations for insect pollination.
Question 11 (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
Explanation: Selective breeding involves choosing plants or animals with desirable traits and breeding them to produce offspring with those traits. This is a form of artificial selection, as humans control the breeding process.
Question 12 (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
Question 13 (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
Explanation: During eutrophication, the growth of producers (1) increases due to nutrient enrichment, leading to an increase in the number of aerobic bacteria (2) and the rate of decomposition (3) as organic matter accumulates.
Question 14 (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
Explanation: Chromatography is a technique used to separate mixtures of coloured compounds based on their different solubilities in a solvent and their affinity for the stationary phase.
Question 15 (C2.2)
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
Explanation: Isotopes of the same element have the same number of protons and electrons, giving them the same chemical properties. Isotopes 1 and 3 are isotopes of the same element.
Question 16 (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
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, the mass of hydrogen is (3/17) × 51 = 9 g.
Question 17 (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
Explanation: At the cathode, reduction occurs. Pb²⁺ ions gain electrons to form lead metal: Pb²⁺ + 2e⁻ → Pb.
Question 18 (C5.1)
The diagram shows the energy change for the reactions between hydrogen and the halogens.
The reaction is H₂ + X₂ → 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?
| 1 | 2 | 3 | |
|---|---|---|---|
| A | endothermic | fluorine | least |
| B | endothermic | iodine | least |
| C | exothermic | fluorine | greatest |
| D | exothermic | iodine | greatest |
▶️Answer/Explanation
Answer: C
Explanation: The reaction between hydrogen and halogens is exothermic (1). Fluorine (2) is the most reactive halogen, so the energy change for this reaction is the greatest (3).
Question 19 (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
Question 20 (C7.1)
A label from a packet of indigestion tablets is shown. Each tablet contains:
Which substance does not neutralise stomach acid?
A. magnesium carbonate
B. magnesium hydroxide
C. magnesium oxide
D. magnesium sulfate
▶️Answer/Explanation
Answer: D
Explanation: Magnesium sulfate does not react with stomach acid (HCl) to neutralise it. The other substances (magnesium carbonate, magnesium hydroxide, and magnesium oxide) all react with HCl to neutralise it.
Question 21 (C12.5)
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
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 sodium hydroxide is added to solution Y, a white precipitate of calcium hydroxide forms, which remains in excess sodium hydroxide.
Question 22 (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
Question 23 (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
Explanation: Transition metals form coloured compounds due to the presence of partially filled d-orbitals, which allow for the absorption and emission of visible light.
Question 24 (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
Explanation: Lead can be extracted by heating its oxide with carbon because lead is below carbon in the reactivity series. Aluminium cannot be extracted by heating its oxide with carbon, as it is above carbon in the reactivity series.
Question 25 (C11.4)
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
Explanation: The Haber process requires a catalyst (usually iron) to speed up the reaction between nitrogen and hydrogen to produce ammonia. It operates at high pressure and moderate temperature, and sulfuric acid is not produced.
Question 26 (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
Explanation: Naphtha is a fraction obtained from petroleum distillation and is primarily used as a feedstock for making chemicals, such as plastics and synthetic materials.
Question 27 (C11.5)
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
Explanation: The reaction between ethene and steam to produce ethanol is an addition reaction, where the double bond in ethene breaks and water (steam) is added across the bond.
Question 28 (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
Question 29 (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
Explanation: The moment is calculated as force × distance. Convert 360 cm to meters (3.6 m). Moment = 120 N × 3.6 m = 432 N m.
Question 30 (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
Explanation: Power is calculated as work done / time. Work done = force × distance = (300 kg × 10 N/kg) × 20 m = 60,000 J. Time = 60 seconds. Power = 60,000 J / 60 s = 1000 W.
Question 31 (P2.3.2)
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?
| Process | Density of hot air | |
|---|---|---|
| A | conduction | greater than cool air |
| B | conduction | less than cool air |
| C | convection | greater than cool air |
| D | convection | less than cool air |
▶️Answer/Explanation
Answer: D
Explanation: The process described is convection, where hot air rises because it is less dense than cool air. Cool air, being denser, falls to replace the rising hot air.
Question 32 (P2.1.3)
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.
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?
| Average speed of molecules | Number of collisions each second | |
|---|---|---|
| A | increases | decreases |
| B | increases | increases |
| C | unchanged | decreases |
| D | unchanged | increases |
▶️Answer/Explanation
Answer: C
Explanation: At constant temperature, the average speed of gas molecules remains unchanged. However, as the volume increases, the number of collisions with the piston decreases because the molecules are more spread out.
Question 33 (P3.2.3)
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?
| Principal focus | Size of image | |
|---|---|---|
| A | X | larger than object |
| B | X | smaller than object |
| C | Y | larger than object |
| D | Y | smaller than object |
▶️Answer/Explanation
Answer: A
Explanation: Point X is the principal focus of the lens. The image formed is larger than the object because the object is placed between the focal point and the lens, resulting in a magnified image.
Question 34 (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?
| Speed of sound in water (m/s) | Speed of sound in steel (m/s) | Speed of sound in air (m/s) | |
|---|---|---|---|
| A | 300 | 1500 | 4500 |
| B | 300 | 4500 | 1500 |
| C | 1500 | 4500 | 300 |
| D | 4500 | 1500 | 300 |
▶️Answer/Explanation
Answer: C
Explanation: Sound travels fastest in solids (steel), slower in liquids (water), and slowest in gases (air). The correct speeds are 1500 m/s in water, 4500 m/s in steel, and 300 m/s in air.
Question 35 (P4.2.1)
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 in which an electric charge experiences a force. The strength and direction of the field determine the force experienced by the charge.
Question 36 (P4.2.3)
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 e.m.f. of a battery is the energy supplied per unit charge. For a 2.0 V battery, it supplies 2.0 J of energy for every 1.0 C of charge driven around the circuit.
Question 37 (P4.5.3)
Which diagram shows the pattern of the magnetic field due to a current in a straight wire?
▶️Answer/Explanation
Answer: A
Question 38 (P4.5.6)
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 increase the voltage for transmission, which reduces the current. Since power loss in transmission cables is proportional to the square of the current, reducing the current minimizes energy loss.
Question 39 (P5.1)
The table compares an atom of carbon-13 and an atom of nitrogen-14.
| Carbon-13 | Nitrogen-14 | |
|---|---|---|
| Nucleon number A | 13 | 14 |
| Proton number Z | 6 | 7 |
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 7 neutrons (13 – 6 = 7), and nitrogen-14 also has 7 neutrons (14 – 7 = 7). Therefore, they have the same number of neutrons.
Question 40 (P5.2.2)
α, β, and γ radiation can all penetrate materials and ionise atoms. Which row compares the different types of radiation?
| Least penetrating | Least ionising | |
|---|---|---|
| A | α | β |
| B | α | γ |
| C | γ | α |
| D | γ | β |
▶️Answer/Explanation
Answer: B
Explanation: α radiation is the least penetrating but the most ionising, while γ radiation is the most penetrating but the least ionising. Therefore, the correct comparison is α (least penetrating) and γ (least ionising).