Question 1 (Subtopic – B1.1)
All living organisms can break down nutrient molecules to release energy. What is this process?
- A. excretion
- B. growth
- C. nutrition
- D. respiration
▶️Answer/Explanation
Answer: D. respiration
Explanation: Respiration is the process by which living organisms break down nutrient molecules to release energy. This energy is used for various metabolic activities in the body. Excretion, growth, and nutrition are other life processes but do not directly involve the breakdown of nutrient molecules to release energy.
Question 2 (Subtopic – B2.1)
The diagram shows a plant cell as seen under a light microscope.
Which structure is also found in animal cells?
- A. cell wall
- B. chloroplast
- C. vacuole
- D. nucleus
▶️Answer/Explanation
Answer: D. nucleus
Explanation: The nucleus is a structure found in both plant and animal cells. It contains the cell’s genetic material and controls cellular activities.
Question 3 (Subtopic – 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 (Subtopic – B5.1)
A student carried out an investigation on the effect of temperature on an enzyme-controlled reaction. The results are shown.
Which labels does the student need to add for the axes labelled axis 1 and axis 2?
| Axis 1 | Axis 2 |
|---|---|
| A. rate of reaction | temperature |
| B. rate of reaction | time |
| C. temperature | rate of reaction |
| D. time | rate of reaction |
▶️Answer/Explanation
Answer: C. temperature (Axis 1) and rate of reaction (Axis 2)
Explanation: In an enzyme-controlled reaction, the independent variable (temperature) is typically plotted on the x-axis (Axis 1), and the dependent variable (rate of reaction) is plotted on the y-axis (Axis 2).
Question 5 (Subtopic – B6.1)
The diagram shows an experiment to investigate photosynthesis. When leaves photosynthesise, they store some carbohydrates as starch. Potassium hydroxide absorbs carbon dioxide.
After standing in sunlight for 10 hours, leaf L contained no starch but leaf M contained a lot of starch.
What does this show?
- A. A leaf cannot make starch in a sealed flask.
- B. A leaf cannot make starch without carbon dioxide.
- C. A leaf cannot make starch without light.
- D. A leaf cannot make starch without oxygen.
▶️Answer/Explanation
Answer: B. A leaf cannot make starch without carbon dioxide.
Explanation: Since potassium hydroxide absorbs carbon dioxide, leaf L did not have access to CO₂ and therefore could not photosynthesize and produce starch. Leaf M, which had access to CO₂, was able to photosynthesize and produce starch.
Question 6 (Subtopic – 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.
Question 7 (Subtopic – B9.2)
The diagram shows a section through a mammalian heart.
Which vessel is the pulmonary vein?
- A. A
- B. B
- C. C
- D. D
▶️Answer/Explanation
Answer: D. D
Explanation: The pulmonary vein carries oxygenated blood from the lungs to the left atrium of the heart. In the diagram, vessel D is the pulmonary vein.
Question 8 (Subtopic – B11.1)
The graph shows the 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 (rate of breathing) and increase (depth of breathing)
Explanation: During exercise, the body requires more oxygen, so both the rate and depth of breathing increase to meet this demand.
Question 9 (Subtopic – B13.2)
Adrenaline is injected into the blood to treat some medical conditions. What would happen as a result of injecting adrenaline?
- 1. narrowing of the pupil in the eye
- 2. increased breathing rate
- 3. increased pulse rate
- A. 1 and 2 only
- B. 1 and 3 only
- C. 2 and 3 only
- D. 1, 2 and 3
▶️Answer/Explanation
Answer: C. 2 and 3 only
Explanation: Adrenaline increases the breathing rate and pulse rate to prepare the body for a “fight or flight” response. It does not cause the pupil to narrow; instead, it causes the pupil to dilate.
Question 10 (Subtopic – B15.4)
The diagram shows the female reproductive system.
Which labelled part is the cervix?
- A. A
- B. B
- C. C
- D. D
▶️Answer/Explanation
Answer: B. B
Explanation: The cervix is the lower part of the uterus that connects to the vagina. In the diagram, part B represents the cervix.
Question 11(Sub-topic – B16.1)
In a species of flowering plant, the allele for red flowers is dominant to the allele for white flowers. A plant breeder crossed a homozygous white-flowered plant with a heterozygous red-flowered plant. What is the expected phenotypic ratio of the next generation of plants?
A) 1 white : 1 red
B) 3 red : 1 white
C) 3 white : 1 red
D) all the plants will be red
▶️Answer/Explanation
Answer: A) 1 white : 1 red
Explanation: The homozygous white-flowered plant has the genotype rr, and the heterozygous red-flowered plant has the genotype Rr. The cross between them (rr x Rr) will produce offspring with genotypes Rr and rr in a 1:1 ratio. Since R (red) is dominant over r (white), the phenotypic ratio will be 1 red : 1 white.
Question 12 (Sub-topic – B18.2)
Which organism is a secondary consumer in the food chain shown?
plant → herbivore → carnivore → top carnivore
A) plant
B) herbivore
C) carnivore
D) top carnivore
▶️Answer/Explanation
Answer: C) carnivore
Explanation: In the given food chain, the plant is the producer, the herbivore is the primary consumer, the carnivore is the secondary consumer, and the top carnivore is the tertiary consumer.
Question 13 (Sub-topic – B18.3)
The diagram shows a simplified carbon cycle.
Which labelled arrow represents respiration?
A) CO₂
B) green plants
C) animals
D) fossil fuels
▶️Answer/Explanation
Answer: C) animals
Explanation: Respiration in animals releases carbon dioxide (CO₂) into the atmosphere, which is represented by the arrow from animals to CO₂ in the carbon cycle.
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, while combustion and neutralisation are chemical changes.
Question 15 (Sub-topic – C2.4)
Which row describes the physical properties of the named substances?
| substance | solubility in water | electrical conductivity as a solid | electrical conductivity as a liquid | |
|---|---|---|---|---|
| A | ammonia | low | good | good |
| B | copper chloride | high | poor | good |
| C | iron nitrate | high | good | good |
| D | potassium chloride | low | poor | poor |
▶️Answer/Explanation
Answer: B) copper chloride | high | poor | good
Explanation: Copper chloride is highly soluble in water, does not conduct electricity as a solid, but conducts electricity when dissolved in water or in its molten state.
Question 16 (Sub-topic – C2.5)
A model of a molecule is shown.
Which row shows the formula of this molecule and describes the type of bonding between the atoms?
A) 2BH₃ | covalent
B) 2BH₃ | ionic
C) B₂H₆ | covalent
D) B₂H₆ | ionic
▶️Answer/Explanation
Answer: C) B₂H₆ | covalent
Explanation: The molecule shown is B₂H₆, which is diborane. The bonding between boron and hydrogen is covalent, as they share electrons.
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?
A) anode | bromine
B) anode | chlorine
C) cathode | bromine
D) cathode | chlorine
▶️Answer/Explanation
Answer: A) anode | bromine
Explanation: In electrolysis, the positive electrode is the anode, and the formation of an orange color suggests the presence of bromine, which is a halogen.
Question 18 (Sub-topic – C5.1)
Magnesium ribbon is added to dilute hydrochloric acid. Which observation shows that this process is exothermic?
A) The pH of the solution decreases.
B) The pH of the solution increases.
C) The temperature of the solution decreases.
D) The temperature of the solution increases.
▶️Answer/Explanation
Answer: D) The temperature of the solution increases.
Explanation: An exothermic reaction releases heat, causing the temperature of the solution to increase.
Question 19 (Sub-topic – C6.2)
A known mass of solid sodium carbonate is added to excess hydrochloric acid. Which conditions give the shortest reaction time?
| solid particle size | acid concentration | |
|---|---|---|
| A | large | high |
| B | large | low |
| C | small | high |
| D | small | low |
▶️Answer/Explanation
Answer: C) small | high
Explanation: Smaller particle size increases the surface area, and higher acid concentration increases the reaction rate, leading to the shortest reaction time.
Question 20 (Sub-topic – C12.5)
A white solid X dissolves in dilute hydrochloric acid. A gas is produced which turns limewater milky. A flame test is carried out on solid X and produces a red-colored flame. What is X?
A) lithium carbonate
B) lithium chloride
C) potassium carbonate
D) potassium chloride
▶️Answer/Explanation
Answer: A) lithium carbonate
Explanation: The gas produced (CO₂) turns limewater milky, indicating the presence of a carbonate. The red flame test indicates the presence of lithium.
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 colored compounds. Metals 2 and 3 fit these criteria.
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.
Question 23 (Sub-topic – C10.1)
Which colour is observed when water is added to anhydrous copper(II) sulfate?
A) blue
B) green
C) pink
D) white
▶️Answer/Explanation
Answer: A) blue
Explanation: Anhydrous copper(II) sulfate is white, but it turns blue when water is added, forming hydrated copper(II) sulfate.
Question 24 (Sub-topic – C10.2)
Which process does not produce carbon dioxide?
A) complete combustion of fossil fuels
B) reaction of an acid with a carbonate
C) respiration in plants
D) rusting iron
▶️Answer/Explanation
Answer: D) rusting iron
Explanation: Rusting iron involves the reaction of iron with oxygen and water to form iron oxide, but it does not produce carbon dioxide.
Question 25 (Sub-topic – C7.3)
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 neutralize acidic gases, such as sulfur dioxide, in processes like flue gas desulfurization.
Question 26 (Sub-topic – C11.2)
Four molecules are shown.
Which structure represents ethanol?
A) CH₃CH₂OH
B) CH₃COOH
C) CH₃CH₂CH₃
D) CH₃CH₂CH₂OH
▶️Answer/Explanation
Answer: A) CH₃CH₂OH
Explanation: Ethanol has the molecular formula CH₃CH₂OH, which is represented by option A.
Question 27 (Sub-topic – C11.5)
Which process produces alkenes from alkanes?
A) combustion
B) cracking
C) oxidation
D) reduction
▶️Answer/Explanation
Answer: B) cracking
Explanation: Cracking is a process that breaks down larger alkane molecules into smaller alkenes and alkanes.
Question 28 (Sub-topic – P1.2)
Which speed–time graph represents the motion of an object in free fall with no air resistance?
A) speed increases linearly with time
B) speed decreases linearly with time
C) speed remains constant with time
D) speed increases at a constant rate with time
▶️Answer/Explanation
Answer: D) speed increases at a constant rate with time
Explanation: In free fall, the speed of an object increases at a constant rate due to the acceleration caused by gravity, resulting in a linear increase in speed over time.
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 point.
Question 30 (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 gravitational potential energy decreases while its kinetic energy increases due to the conversion of potential energy into kinetic energy.
Question 31 (Sub-topic – P1.6.4)
Four different kettles contain different masses of water. They are used to heat the water from 20 °C to 100 °C. Each kettle takes a different amount of time to do this. Which kettle has the lowest useful power output?
| mass of water/g | time to heat water to 100 °C/minute | |
|---|---|---|
| A | 1000 | 3.0 |
| B | 1000 | 5.0 |
| C | 2500 | 3.0 |
| D | 2500 | 5.0 |
▶️Answer/Explanation
Answer: B) 1000 | 5.0
Explanation: Power output is inversely proportional to the time taken to heat the water. Kettle B takes the longest time (5.0 minutes) to heat the water, indicating the lowest power output.
Question 32 (Sub-topic – P2.1.1)
Which labelled arrow on the diagram represents condensation?
A) liquid to gas
B) gas to liquid
C) solid to liquid
D) liquid to solid
▶️Answer/Explanation
Answer: B) gas to liquid
Explanation: Condensation is the process by which a gas changes into a liquid, represented by the arrow from gas to liquid.
Question 33 (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 34 (Sub-topic – P4.1)
The diagrams P, Q, R and S show four pairs of bar magnets.
For which two pairs of magnets is there a force of attraction between the magnets?
A) P and Q
B) Q and R
C) R and S
D) P and S
▶️Answer/Explanation
Answer: A) P and Q
Explanation: Magnets attract when opposite poles (north and south) are facing each other. P and Q show this configuration.
Question 35 (Sub-topic – P4.2.1)
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 by hand and the strip is attracted, the rod must be an insulator.
Question 36 (Sub-topic – P4.3.2)
Two lamps are connected in the circuit shown.
Which of these two statements about the circuit are correct?
1) There is a separate switch to control each lamp.
2) The ammeter measures the current in both lamps.
A) neither 1 nor 2
B) 1 only
C) 2 only
D) 1 and 2
▶️Answer/Explanation
Answer: B) 1 only
Explanation: In the circuit, each lamp has a separate switch, but the ammeter measures the total current in the circuit, not just the current in both lamps.
Question 37 (Sub-topic – P4.3.2)
Three resistors are connected in series with a battery, as shown.
The current at point P is 6.0 A. What is the current at point Q?
A) 0 A
B) 2.0 A
C) 3.0 A
D) 6.0 A
▶️Answer/Explanation
Answer: D) 6.0 A
Explanation: In a series circuit, the current is the same at all points. Therefore, the current at point Q is also 6.0 A.
Question 38 (Sub-topic – P4.4)
An electric kettle, washing machine and cooker are all switched on and connected through an extension cable into a single mains socket.
What is the electrical hazard of this arrangement?
A) The cooker overheats.
B) The extension cable overheats.
C) The kettle overheats.
D) The washing machine overheats.
▶️Answer/Explanation
Answer: B) The extension cable overheats.
Explanation: Connecting multiple high-power appliances to a single extension cable can cause the cable to overheat due to excessive current flow, posing a fire hazard.
Question 39 (Sub-topic – P4.5.5)
There is a current in a coil of wire. The coil rotates between the poles of a magnet. Which change does not increase the turning effect on the coil?
A) increasing the current in the coil
B) reversing the current
C) using a stronger magnet
D) using more turns in the coil
▶️Answer/Explanation
Answer: B) reversing the current
Explanation: Reversing the current changes the direction of the turning effect but does not increase its magnitude. Increasing the current, using a stronger magnet, or using more turns in the coil all increase the turning effect.
Question 40 (Sub-topic – P5.1)
The table gives information about four nuclides P, Q, R and S. Which nuclides are isotopes of the same element?
| nuclide | number of protons | number of neutrons |
|---|---|---|
| P | 81 | 123 |
| Q | 82 | 122 |
| R | 82 | 123 |
| S | 83 | 121 |
A) P and Q
B) P and R
C) Q and R
D) Q and S
▶️Answer/Explanation
Answer: C) Q and R
Explanation: Isotopes of the same element have the same number of protons but different numbers of neutrons. Q and R both have 82 protons, making them isotopes of the same element.