Question 1 (Subtopic code-B1.1)
During a sunny day, stomata are open to allow gas exchange. Oxygen moves out of the plant through the stomata. Which characteristic of living things is described?
A. excretion
B. movement
C. reproduction
D. respiration
▶️Answer/Explanation
Answer: A. excretion
Explanation: The movement of oxygen out of the plant through the stomata is related to the removal of waste products, which is a characteristic of excretion. Excretion is the process by which organisms remove metabolic waste products from their bodies.
Question 2 (Subtopic code-B2.1)
Which statement about cells is correct?
A. Cell membranes are found only in animal cells.
B. Cell membranes are found only in plant cells.
C. Cell walls are found only in animal cells.
D. Cell walls are found only in plant cells.
▶️Answer/Explanation
Answer: D. Cell walls are found only in plant cells.
Explanation: Cell walls are a rigid structure found in plant cells, providing support and protection. Animal cells do not have cell walls; they only have cell membranes.
Question 3 (Subtopic code-B4.1)
Large biological molecules are made from smaller molecules joined together. Which large molecule is correctly matched with its smaller molecule?
| Large molecule | Smaller molecule |
|---|---|
| A. fat | amino acid |
| B. glycogen | glucose |
| C. starch | fatty acid |
| D. protein | glycerol |
▶️Answer/Explanation
Answer: B. glycogen – glucose
Explanation: Glycogen is a polysaccharide made up of glucose monomers. It serves as a form of energy storage in animals.
Question 4 (Subtopic code-B5.1)
The graph shows the effect of temperature on the time taken for a protease to digest protein. At which point on the graph is the greatest frequency of effective collisions between enzyme and substrate?
▶️Answer/Explanation
Answer: C. The point where the time taken to digest protein is the shortest.
Explanation: The greatest frequency of effective collisions between enzyme and substrate occurs at the temperature where the enzyme is most active, which is typically the point where the reaction rate is highest (i.e., the time taken to digest protein is the shortest).
Question 5 (Subtopic code-B6.1)
Which graph shows the effect of light intensity on the rate of photosynthesis, if all other factors are kept constant?
▶️Answer/Explanation
Answer: D. The graph where the rate of photosynthesis increases with light intensity and then plateaus.
Explanation: The rate of photosynthesis increases with light intensity up to a certain point, after which it plateaus because other factors (such as CO2 concentration or temperature) become limiting.
Question 6 (Subtopic code-B7.2 )
The diagram shows part of the digestive system.
Which labelled parts produce digestive enzymes, absorb water, and store bile?
▶️Answer/Explanation
Answer: C. R produces digestive enzymes, S absorbs water, and P stores bile.
Explanation: In the digestive system, the pancreas (R) produces digestive enzymes, the large intestine (S) absorbs water, and the gallbladder (P) stores bile.
Question 7 (Subtopic code-B9.2)
Students investigate the effect of exercise on heart rate. The graph shows the results.
How long does it take for the heart rate to decrease to the resting rate after the student stops exercising?
A. 3 minutes
B. 5 minutes
C. 7.5 minutes
D. 9 minutes
▶️Answer/Explanation
Answer: A. 3 minutes
Explanation: The graph shows that the heart rate returns to the resting rate approximately 3 minutes after the student stops exercising.
Question 8 (Subtopic code-B12.1)
What is the relative concentration of glucose, lactic acid, and oxygen in the muscles immediately after extreme exercise?
| Glucose | Lactic acid | Oxygen |
|---|---|---|
| A. high | high | low |
| B. high | low | high |
| C. low | high | low |
| D. low | low | high |
▶️Answer/Explanation
Answer: C. low glucose, high lactic acid, low oxygen
Explanation: After extreme exercise, glucose levels are low due to high energy consumption, lactic acid levels are high due to anaerobic respiration, and oxygen levels are low because the body has not yet fully recovered.
Question 9 (Subtopic code-B13.3)
Which statement about temperature control is correct?
A. Vasoconstriction near the skin surface and shivering will cool the body down.
B. Vasoconstriction near the skin surface and sweating will warm the body up.
C. Vasodilation near the skin surface and shivering will warm the body up.
D. Vasodilation near the skin surface and sweating will cool the body down.
▶️Answer/Explanation
Answer: D. Vasodilation near the skin surface and sweating will cool the body down.
Explanation: Vasodilation increases blood flow to the skin, allowing heat to be lost, and sweating helps cool the body through evaporation.
Question 10 (Subtopic code-B15.1)
The diagram shows the life cycle of a marine organism called a hydrozoan.
Which statements about the life cycle of hydrozoa are correct?
1. Hydrozoa reproduce asexually.
2. Hydrozoa reproduce sexually.
3. Fusion of haploid gametes produces a diploid zygote.
▶️Answer/Explanation
Answer: D. 1, 2, and 3
Explanation: Hydrozoa can reproduce both asexually (through budding) and sexually (through the fusion of haploid gametes to form a diploid zygote).
Question 11 (Sub-topic Code:B2.1)
Which diagram about haploid and diploid cells in humans is correct?
▶️Answer/Explanation
Answer: B
Explanation: In humans, haploid cells (gametes) contain 23 chromosomes, while diploid cells (body cells) contain 46 chromosomes. Therefore, option B is correct.
Question 12(Sub-topic Code: B18.2)
Which organisms obtain energy directly from every trophic level?
A) Carnivores
B) Decomposers
C) Herbivores
D) Producers
▶️Answer/Explanation
Answer: B
Explanation: Decomposers obtain energy by breaking down dead organisms and waste materials from all trophic levels, making them the correct answer.
Question 13 (Sub-topic Code: B19.1)
How does deforestation change the concentrations of carbon dioxide and oxygen in the atmosphere?
▶️Answer/Explanation
Answer: A
Explanation: Deforestation reduces the number of trees that absorb carbon dioxide and produce oxygen, leading to an increase in carbon dioxide and a decrease in oxygen levels in the atmosphere.
Question 14 (Sub-topic Code: C7.3)
Information about the solubility in water of some calcium compounds is listed.
Calcium hydroxide is soluble.
Calcium carbonate is insoluble.
Calcium chloride is soluble.
Which method is used to prepare pure calcium chloride?
A) Add excess calcium hydroxide to dilute hydrochloric acid, filter, then crystallise.
B) Add excess calcium carbonate to dilute hydrochloric acid, filter, then crystallise.
C) Add excess dilute hydrochloric acid to calcium hydroxide, filter, then crystallise.
D) Add excess dilute hydrochloric acid to calcium carbonate, filter, then crystallise.
▶️Answer/Explanation
Answer: B
Explanation: Calcium carbonate is insoluble in water, so adding excess calcium carbonate to dilute hydrochloric acid will ensure all the acid is neutralized, and the resulting calcium chloride can be filtered and crystallized to obtain a pure sample.
Question 15 (Sub-topic Code: C6.1)
Which process is a chemical change?
A) Boiling
B) Dissolving
C) Melting
D) Neutralisation
▶️Answer/Explanation
Answer: D
Explanation: Neutralisation is a chemical change because it involves the reaction between an acid and a base to form a salt and water, resulting in a new substance being formed.
Question 16 (Sub-topic Code: C2.4)
Sodium phosphate, Na3PO4, contains sodium ions, Na+.
Aluminium sulfate, Al2(SO4)3, contains sulfate ions, SO42-.
What is the formula of aluminium phosphate?
A) AlPO4
B) Al(PO4)2
C) Al2(PO4)3
D) Al3(PO4)2
▶️Answer/Explanation
Answer: A
Explanation: Aluminium has a +3 charge, and phosphate has a -3 charge. Therefore, one aluminium ion combines with one phosphate ion to form AlPO4.
Question 17 (Sub-topic Code: C4.1)
Aqueous copper(II) sulfate is electrolysed using carbon electrodes. Which row describes the observations and products at each electrode during this process?
▶️Answer/Explanation
Answer: C
Explanation: During the electrolysis of aqueous copper(II) sulfate, copper is deposited at the cathode as an orange-brown solid, and oxygen gas is produced at the anode, forming bubbles.
Question 18 (Sub-topic Code: C6.3)
Magnesium reacts with chlorine to form magnesium chloride.
Which statement about this reaction is correct?
A) The magnesium is being reduced.
B) The oxidising agent is chlorine.
C) The reaction involves oxidation but not reduction.
D) There is no oxygen involved so there is no oxidation.
▶️Answer/Explanation
Answer: B
Explanation: In this reaction, chlorine acts as the oxidizing agent because it gains electrons from magnesium, which is being oxidized.
Question 19 (Sub-topic Code: C7.1)
Which substance changes the colour of damp red litmus?
A) CO2
B) Cl2
C) H2
D) SO2
▶️Answer/Explanation
Answer: B
Explanation: Chlorine gas (Cl2) is a strong oxidizing agent and will bleach damp red litmus paper, changing its color.
Question 20 (Sub-topic Code: C9.1)
A gas is used in welding metals together at high temperatures. The gas is used to provide an inert atmosphere. What is the gas?
A) Argon
B) Carbon dioxide
C) Fluorine
D) Oxygen
▶️Answer/Explanation
Answer: A
Explanation: Argon is an inert gas and is commonly used in welding to create an inert atmosphere that prevents oxidation of the metals being welded.
Question 21 (Sub-topic Code: C9.1)
Which row does not link a general physical property to the type of element?
▶️Answer/Explanation
Answer: C
Explanation: Non-metals are generally poor electrical conductors, with the exception of graphite (a form of carbon). Therefore, the statement that non-metals are electrical conductors is incorrect.
Question 22 (Sub-topic Code: C9.4)
Which metal oxide is reduced when heated with magnesium powder?
A calcium oxide
B copper oxide
C magnesium oxide
D sodium oxide
▶️Answer/Explanation
Answer: B
Explanation: Magnesium is more reactive than copper, so it can reduce copper oxide to copper. The reaction is: Mg + CuO → MgO + Cu.
Question 23 (Sub-topic Code: C9.5)
Zinc is used to galvanise iron. Which statements about galvanising are correct?
- Iron is more reactive than zinc.
- Zinc oxidises instead of iron.
- Galvanised iron rusts if the zinc coating is scratched.
- Galvanising iron is an example of sacrificial protection.
| A | 1 and 2 |
| B | 1 and 3 |
| C | 2 and 4 |
| D | 3 and 4 |
▶️Answer/Explanation
Answer: C
Explanation: Zinc is more reactive than iron, so it oxidises instead of iron, providing sacrificial protection. Galvanising is indeed an example of sacrificial protection. However, if the zinc coating is scratched, the iron underneath can still rust, so statement 3 is incorrect.
Question 24 (Sub-topic Code: C6.3)
Which equation does not represent a reaction that occurs in the Contact process?
| A | 2S + 3O2 → 2SO3 |
| B | 2SO2 + O2 ⇌ 2SO3 |
| C | H2SO4 + SO3 → H2S2O7 |
| D | H2S2O7 + H2O → 2H2SO4 |
▶️Answer/Explanation
Answer: A
Explanation: The Contact process involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3), not the direct oxidation of sulfur (S) to sulfur trioxide. Therefore, the equation 2S + 3O2 → 2SO3 does not represent a reaction in the Contact process.
Question 25 (Sub-topic Code: C10.1)
Why do farmers add limestone to soil?
| A | It acts as a fertiliser. |
| B | It adds nitrogen to the soil. |
| C | It decreases the pH of the soil. |
| D | It increases the pH of the soil. |
▶️Answer/Explanation
Answer: D
Explanation: Limestone (calcium carbonate) is added to soil to neutralize acidity, thereby increasing the pH of the soil. It does not act as a fertiliser or add nitrogen to the soil.
Question 26 (Sub-topic Code: C11.3)
Petroleum is a mixture of hydrocarbons which is separated into fractions by fractional distillation. Which statements describe the fraction collected at the bottom of the fractionating column?
- It contains the smallest molecules.
- It has the weakest forces between molecules.
- It is the most viscous.
- It is the least flammable.
| A | 1 and 2 |
| B | 1 and 3 |
| C | 2 and 4 |
| D | 3 and 4 |
▶️Answer/Explanation
Answer: D
Explanation: The fraction collected at the bottom of the fractionating column contains larger hydrocarbon molecules, which are more viscous and less flammable. Therefore, statements 3 and 4 are correct.
Question 27 (Sub-topic Code: C11.7)
The structure of a monomer is shown. Which structure represents the addition polymer formed by this monomer?
Options A, B, C, and D are provided as images of polymer structures.
▶️Answer/Explanation
Answer: C
Explanation: The addition polymer formed by the monomer will have a repeating unit that matches the structure of the monomer. Option C correctly represents the polymer structure formed by the given monomer.
Question 28 (Sub-topic Code: P1.2)
Which speed–time graph represents an object travelling at constant speed?
Options A, B, C, and D are provided as speed–time graphs.
▶️Answer/Explanation
Answer: C
Explanation: A constant speed is represented by a horizontal line on a speed–time graph, indicating that the speed does not change over time. Option C shows a horizontal line, representing constant speed.
Question 29 (Sub-topic Code: P1.5.1)
A parachutist falls vertically at constant speed. Which statement about the resultant force on the parachutist is correct?
| A | The resultant force on the parachutist acts vertically downwards. |
| B | The resultant force on the parachutist acts vertically upwards. |
| C | The resultant force on the parachutist is equal to his weight. |
| D | The resultant force on the parachutist is equal to zero. |
▶️Answer/Explanation
Answer: D
Explanation: When the parachutist is falling at a constant speed, the forces acting on him are balanced. The resultant force is zero because the gravitational force (weight) is balanced by the air resistance (drag).
Question 30 (Sub-topic Code: P1.6.1)
An object moving at speed \( v \) has kinetic energy \( E \). What is the speed of the object when its kinetic energy is 4.0 \( E \)?
| A | 0.25 \( v \) |
| B | 2.0 \( v \) |
| C | 4.0 \( v \) |
| D | 16 \( v \) |
▶️Answer/Explanation
Answer: B
Explanation: Kinetic energy is proportional to the square of the speed. If the kinetic energy increases by a factor of 4, the speed must increase by a factor of 2, since \( 2^2 = 4 \). Therefore, the new speed is \( 2.0v \).
Question 31 (Sub-topic Code: P6.2.1)
What is the name of the process by which energy is released in the Sun?
A. background radiation
B. chemical reaction
C. nuclear fission
D. nuclear fusion
▶️Answer/Explanation
Answer: D. nuclear fusion
Explanation: The Sun releases energy through the process of nuclear fusion, where hydrogen nuclei combine to form helium, releasing a tremendous amount of energy in the process.
Question 32 (Sub-topic Code: P2.2.2)
What happens to the temperature of a substance as it is melting and as it is boiling?
| melting | boiling | |
|---|---|---|
| A | decreases | increases |
| B | decreases | no change |
| C | increases | increases |
| D | no change | no change |
▶️Answer/Explanation
Answer: D. no change
Explanation: During melting and boiling, the temperature of a substance remains constant because the energy supplied is used to change the state of the substance rather than increase its temperature.
Question 33 (Sub-topic Code: P3.1)
A loudspeaker produces a sound wave that has a frequency of 3300 Hz. The speed of sound in air is 330 m/s. What is the wavelength of the sound wave?
A. 0.10 m
B. 1.0 m
C. 11 m
D. 1.1 × 106 m
▶️Answer/Explanation
Answer: A. 0.10 m
Explanation: The wavelength (λ) can be calculated using the formula λ = v / f, where v is the speed of sound and f is the frequency. Substituting the given values, λ = 330 m/s / 3300 Hz = 0.10 m.
Question 34 (Sub-topic Code: P3.2.3)
A lens is used as a magnifying glass to form a magnified image of some writing on a page.
Which statements are correct?
1. The lens is a converging lens.
2. The writing is closer to the lens than one focal length of the lens.
3. The magnified image is a virtual image.
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: A magnifying glass uses a converging lens to produce a magnified virtual image. The object (writing) must be placed closer to the lens than its focal length to achieve this magnification.
Question 35 (Sub-topic Code: P4.1)
An iron bar XY is brought near to a magnet. Magnetic poles are induced in the iron bar.
What are the magnetic poles induced at X and Y?
| pole at X | pole at Y | |
|---|---|---|
| A | N | N |
| B | N | S |
| C | S | N |
| D | S | S |
▶️Answer/Explanation
Answer: C. S at X and N at Y
Explanation: When an iron bar is brought near a magnet, the end closest to the magnet’s north pole becomes a south pole (X), and the far end becomes a north pole (Y).
Question 36 (Sub-topic Code: P4.2.2)
A battery with an electromotive force (e.m.f.) of 6.0 V is connected to a 30 Ω resistor. How much charge flows through the battery in 5.0 s?
A. 1.0 C
B. 25 C
C. 36 C
D. 900 C
▶️Answer/Explanation
Answer: A. 1.0 C
Explanation: The current (I) can be calculated using Ohm’s law: I = V / R = 6.0 V / 30 Ω = 0.2 A. The charge (Q) is then calculated using Q = I × t = 0.2 A × 5.0 s = 1.0 C.
Question 37 (Sub-topic Code: P4.3.2)
Which row shows how lamps are connected in a lighting circuit in a house and gives an advantage of connecting them in this way?
| how lamps are connected | advantage of connecting them in this way | |
|---|---|---|
| A | in parallel | they can be switched separately |
| B | in parallel | they share the voltage |
| C | in series | they can be switched separately |
| D | in series | they share the voltage |
▶️Answer/Explanation
Answer: A. in parallel, they can be switched separately
Explanation: Lamps in a house are typically connected in parallel so that each lamp can be switched on and off independently without affecting the others.
Question 38 (Sub-topic Code: P4.5.6)
A transformer increases the voltage from a power station in order to transfer electricity along transmission cables. How does increasing the voltage affect the current in the cables and how does it affect the efficiency of energy transfer?
| current | efficiency | |
|---|---|---|
| A | decreases | decreases |
| B | decreases | increases |
| C | increases | decreases |
| D | increases | increases |
▶️Answer/Explanation
Answer: B. decreases, increases
Explanation: Increasing the voltage reduces the current in the transmission cables, which in turn reduces energy loss due to resistance, thereby increasing the efficiency of energy transfer.
Question 39 (Sub-topic Code: P5.1)
An atom of beryllium is represented by 94Be. How many neutrons are in the nucleus of this type of beryllium atom?
A. 4
B. 5
C. 9
D. 13
▶️Answer/Explanation
Answer: B. 5
Explanation: The number of neutrons is calculated by subtracting the atomic number (4) from the mass number (9). Therefore, 9 – 4 = 5 neutrons.
Question 40 (Sub-topic Code: P5.2.2)
Three different types of ionising radiation X, Y and Z pass between two charged plates.
Which row identifies X, Y and Z?
| X | Y | Z | |
|---|---|---|---|
| A | alpha | beta | gamma |
| B | alpha | gamma | beta |
| C | beta | alpha | gamma |
| D | beta | gamma | alpha |
▶️Answer/Explanation
Answer: B. alpha, gamma, beta
Explanation: Alpha particles are positively charged and will be deflected towards the negative plate. Beta particles are negatively charged and will be deflected towards the positive plate. Gamma rays are neutral and will not be deflected.