Question 1 (Subtopic: B1.1)
Which would be considered movement by an organism?
- a tree’s leaves being blown by the wind
- migration of zebra in Africa
- a student changing their seating position in a classroom
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: Movement in organisms refers to actions that are controlled by the organism itself. The tree’s leaves being blown by the wind (option 1) is not controlled by the tree, so it is not considered movement by the organism. Migration of zebra (option 2) and a student changing their seating position (option 3) are both controlled actions, so they are considered movement by the organism.
Question 2 (Subtopic: B2.2)
The length of an insect in a photograph is measured as 17 mm. The actual length of the insect is 12 mm.
What is the magnification of the insect in the photograph?
A) ×1.2
B) ×1.3
C) ×1.4
D) ×1.5
▶️Answer/Explanation
Answer: C) ×1.4
Explanation: Magnification is calculated using the formula: \[ \text{Magnification} = \frac{\text{Image size}}{\text{Actual size}} \] Substituting the given values: \[ \text{Magnification} = \frac{17\, \text{mm}}{12\, \text{mm}} = 1.416 \approx 1.4 \] Therefore, the magnification is ×1.4.
Question 3 (Subtopic: B4.1)
Which type of biological molecule contains carbon, hydrogen, oxygen, and nitrogen?
A) fat
B) protein
C) reducing sugar
D) starch
▶️Answer/Explanation
Answer: B) protein
Explanation: Proteins are biological molecules that contain carbon, hydrogen, oxygen, and nitrogen. Fats and carbohydrates (like reducing sugar and starch) contain carbon, hydrogen, and oxygen but do not contain nitrogen.
Question 4 (Subtopic: B5.1)
A mixture of starch and saliva was set up at four different temperatures. Each mixture was tested with iodine solution after 15 minutes and again after 30 minutes.
The results are shown in the table:
| Temperature /°C | Colour with iodine solution (15 minutes) | Colour with iodine solution (30 minutes) |
|---|---|---|
| 0 | blue-black | blue-black |
| 15 | blue-black | brown |
| 35 | brown | brown |
| 95 | blue-black | blue-black |
What do the results suggest?
A) The enzyme in saliva is inactive at 95°C.
B) The enzyme in saliva is slow to work at 35°C.
C) The enzyme in saliva works equally well at 15°C and 35°C.
D) The enzyme in saliva works faster at higher temperatures.
▶️Answer/Explanation
Answer: A) The enzyme in saliva is inactive at 95°C.
Explanation: The enzyme in saliva, amylase, breaks down starch into simpler sugars. At 95°C, the enzyme is denatured and becomes inactive, which is why the starch remains unchanged (blue-black colour with iodine). At 35°C, the enzyme is active, and the starch is broken down, resulting in a brown colour. At 15°C, the enzyme is less active, so it takes longer to break down the starch.
Question 5 (Subtopic: B6.1)
Which conditions will result in the highest rate of photosynthesis?
| Light intensity | Carbon dioxide concentration | |
|---|---|---|
| A | high | high |
| B | high | low |
| C | low | high |
| D | low | low |
▶️Answer/Explanation
Answer: A) high light intensity and high carbon dioxide concentration
Explanation: Photosynthesis is most efficient when both light intensity and carbon dioxide concentration are high. Light is necessary for the light-dependent reactions, and carbon dioxide is a reactant in the Calvin cycle. Therefore, both factors must be optimal for the highest rate of photosynthesis.
Question 6 (Subtopic: B7.2)
Into which part of the alimentary canal does the pancreas release digestive juices?
A) anus
B) large intestine
C) oesophagus
D) small intestine
▶️Answer/Explanation
Answer: D) small intestine
Explanation: The pancreas releases digestive juices into the small intestine, specifically the duodenum, where they help in the digestion of carbohydrates, proteins, and fats.
Question 7 (Subtopic: B8.3)
Under which conditions will transpiration from a plant be fastest?
| Temperature | Humidity | |
|---|---|---|
| A | high | high |
| B | high | low |
| C | low | high |
| D | low | low |
▶️Answer/Explanation
Answer: B) high temperature and low humidity
Explanation: Transpiration is the process by which water is lost from the leaves of plants. It is fastest when the temperature is high (increasing the rate of evaporation) and humidity is low (reducing the concentration of water vapor in the air, which increases the rate of diffusion of water out of the leaf).
Question 8 (Subtopic: B12.1)
What is the equation for aerobic respiration?
A) carbon dioxide + water → oxygen + glucose
B) glucose + carbon dioxide → oxygen + water
C) oxygen + glucose → carbon dioxide + water
D) oxygen + water → glucose + carbon dioxide
▶️Answer/Explanation
Answer: C) oxygen + glucose → carbon dioxide + water
Explanation: Aerobic respiration is the process by which cells use oxygen to break down glucose and produce carbon dioxide, water, and energy. The balanced equation is: \[ \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} \]
Question 9 (Subtopic: B13.1)
A plant shoot grows towards a light source. This is an example of what?
A) gravitropism
B) homeostasis
C) transpiration
D) phototropism
▶️Answer/Explanation
Answer: D) phototropism
Explanation: Phototropism is the growth of a plant in response to light. In this case, the plant shoot grows towards the light source, which is an example of positive phototropism.
Question 10 (Subtopic: B15.3)
What describes pollination?
A) fertilisation of an egg by a pollen grain
B) pollen being carried by bees
C) transfer of pollen from a stigma to a stamen
D) transfer of pollen from an anther to a stigma
▶️Answer/Explanation
Answer: D) transfer of pollen from an anther to a stigma
Explanation: Pollination is the transfer of pollen from the anther (male part) to the stigma (female part) of a flower. This can occur through various agents like wind, water, or animals (e.g., bees).
Question 11 (Subtopic: B17.1)
The graph shows the systolic blood pressure of a group of women.
What can be concluded from the graph?
A) Blood pressure shows continuous variation.
B) Blood pressure shows discontinuous variation.
C) Genes affect blood pressure.
D) Women are more at risk of high blood pressure than men.
▶️Answer/Explanation
Answer: A) Blood pressure shows continuous variation.
Explanation: Continuous variation refers to traits that show a range of values (e.g., height, weight, blood pressure). The graph likely shows a range of blood pressure values, indicating continuous variation. Discontinuous variation refers to traits with distinct categories (e.g., blood type).
Question 12 (Subtopic: B18.2)
Which type of organism gets its energy from dead or waste organic matter?
A) carnivore
B) consumer
C) decomposer
D) producer
▶️Answer/Explanation
Answer: C) decomposer
Explanation: Decomposers, such as fungi and bacteria, break down dead or waste organic matter and recycle nutrients back into the ecosystem. Carnivores eat other animals, consumers eat other organisms, and producers (like plants) make their own food through photosynthesis.
Question 13 (Subtopic: B19.1)
The diagram shows a river and four farms. The numbers in the river show relative oxygen concentrations.
From which farm is untreated sewage leaking into the river?
▶️Answer/Explanation
Answer: D) Farm D
Explanation: Untreated sewage contains organic matter that decomposes, consuming oxygen in the water. The lowest oxygen concentration (4) is downstream of Farm D, indicating that untreated sewage is leaking from Farm D.
Question 14 (Subtopic: C2.2)
Atoms are the smallest parts of ……1…… . When atoms of the same type chemically join together, a ……2…… is formed. When different types of atom chemically join together, they form ……3…… .
Which words complete gaps 1, 2, and 3?
A) elements, molecule, compounds
B) elements, molecule, mixtures
C) molecules, compound, mixtures
D) molecules, mixture, compounds
▶️Answer/Explanation
Answer: A) elements, molecule, compounds
Explanation: Atoms are the smallest parts of elements. When atoms of the same type join together, they form molecules (e.g., O2). When different types of atoms join together, they form compounds (e.g., H2O).
Question 15 (Subtopic: C12.4)
An aqueous salt solution contains an insoluble impurity. Which processes are used to obtain pure salt crystals?
A) distillation then crystallisation
B) distillation then chromatography
C) filtration then crystallisation
D) filtration then chromatography
▶️Answer/Explanation
Answer: C) filtration then crystallisation
Explanation: Filtration is used to remove the insoluble impurity, and crystallisation is used to obtain pure salt crystals from the filtered solution.
Question 16 (Subtopic: C2.5)
Which dot-and-cross diagram represents a molecule of ammonia?
▶️Answer/Explanation
Answer: C) Diagram C
Explanation: Ammonia (NH3) has one nitrogen atom sharing three electrons with three hydrogen atoms, forming three covalent bonds. Diagram C correctly shows this structure.
Question 17 (Subtopic: C4.1)
The diagram shows an electroplating experiment.
Which row shows the change in mass of each electrode?
▶️Answer/Explanation
Answer: B) anode: decrease, cathode: increase
Explanation: In electroplating, the anode (positive electrode) loses mass as metal ions dissolve into the solution, while the cathode (negative electrode) gains mass as metal ions are deposited onto it.
Question 18 (Subtopic: C5.1)
Two processes are listed:
- the conversion of liquid water into steam
- the combustion of magnesium ribbon
Which row describes the two processes?
▶️Answer/Explanation
Answer: B) process 1: endothermic, process 2: exothermic
Explanation: The conversion of liquid water into steam requires heat (endothermic), while the combustion of magnesium releases heat (exothermic).
Question 19 (Subtopic: C6.3)
Which word equation represents a redox reaction?
A) carbon + copper oxide → copper + carbon dioxide
B) hydrochloric acid + potassium hydroxide → potassium chloride + water
C) magnesium carbonate → magnesium oxide + carbon dioxide
D) sodium sulfate + barium nitrate → barium sulfate + sodium nitrate
▶️Answer/Explanation
Answer: A) carbon + copper oxide → copper + carbon dioxide
Explanation: In this reaction, carbon is oxidized (loses electrons), and copper oxide is reduced (gains electrons), making it a redox reaction.
Question 20 (Subtopic: C7.1)
Which compound is prepared by reacting an acid with a base?
A) calcium oxide
B) copper hydroxide
C) hydrogen chloride
D) magnesium sulfate
▶️Answer/Explanation
Answer: D) magnesium sulfate
Explanation: Magnesium sulfate is formed by the reaction of sulfuric acid (acid) with magnesium hydroxide (base). This is an example of a neutralization reaction.
Question 21 (Subtopic: C8.2)
Which row shows the trends for Group I elements lithium to potassium?
▶️Answer/Explanation
Answer: B) trend in melting point: decrease, trend in reaction with water: increase
Explanation: In Group I (alkali metals), melting points decrease down the group, and reactivity with water increases down the group. This is because the atoms become larger, and the outer electron is further from the nucleus, making it easier to lose.
Question 22 (Subtopic: C8.4)
Which statement describes transition elements?
A) They form colourless compounds.
B) They have low densities.
C) They have low melting points.
D) They often act as catalysts.
▶️Answer/Explanation
Answer: D) They often act as catalysts.
Explanation: Transition elements are known for their ability to act as catalysts due to their variable oxidation states and ability to form complex ions. They also typically form coloured compounds and have high melting points and densities.
Question 23 (Subtopic: C1.1)
Blue cobalt(II) chloride paper is added to a liquid. It changes from blue to pink.
What is the liquid?
A) bromine
B) ethanol
C) petrol
D) water
▶️Answer/Explanation
Answer: D) water
Explanation: Cobalt(II) chloride paper turns from blue to pink in the presence of water, indicating that the liquid is water.
Question 24 (Subtopic: C6.3)
Which process does not produce carbon dioxide?
A) acid reacting with a metal
B) acid reacting with sodium carbonate
C) complete combustion of methane
D) respiration
▶️Answer/Explanation
Answer: A) acid reacting with a metal
Explanation: When an acid reacts with a metal, hydrogen gas is produced, not carbon dioxide. Carbon dioxide is produced in the other processes: acid reacting with sodium carbonate, complete combustion of methane, and respiration.
Question 25 (Subtopic: C7.1)
Some soil is treated with limestone to make it neutral. What is the pH of the soil before it is treated?
A) 5
B) 7
C) 9
D) 11
▶️Answer/Explanation
Answer: A) 5
Explanation: Limestone (calcium carbonate) is used to neutralize acidic soils. Therefore, the soil must have been acidic (pH less than 7) before treatment. A pH of 5 is acidic.
Question 26 (Subtopic: C11.3)
Which substance is not a fossil fuel?
A) coal
B) hydrogen
C) natural gas
D) petroleum
▶️Answer/Explanation
Answer: B) hydrogen
Explanation: Fossil fuels are formed from the remains of ancient organisms and include coal, natural gas, and petroleum. Hydrogen is not a fossil fuel; it is a clean energy source that can be produced through various methods, including electrolysis of water.
Question 27 (Subtopic: C11.7)
Poly(ethene) is made from ethene by the process of addition polymerisation. Which word describes ethene in this process?
A) fuel
B) catalyst
C) monomer
D) solvent
▶️Answer/Explanation
Answer: C) monomer
Explanation: In polymerization, ethene is the monomer that joins together to form the polymer poly(ethene).
Question 28 (Subtopic: P1.3)
A man has a mass of 80 kg. The gravitational field strength \( g \) is 10 N/kg.
What is the man’s weight?
A) 8.0 N
B) 80 N
C) 800 N
D) 8000 N
▶️Answer/Explanation
Answer: C) 800 N
Explanation: Weight is calculated using the formula: \[ \text{Weight} = \text{mass} \times \text{gravitational field strength} \] Substituting the values: \[ \text{Weight} = 80\, \text{kg} \times 10\, \text{N/kg} = 800\, \text{N} \]
Question 29 (Subtopic: P1.5)
The diagram shows the two forces acting on a skydiver.
What is the resultant force on the skydiver?
A) 400 N downwards
B) 400 N upwards
C) 1000 N downwards
D) 1000 N upwards
▶️Answer/Explanation
Answer: A) 400 N downwards
Explanation: The resultant force is calculated by subtracting the smaller force (air resistance, 600 N) from the larger force (weight, 1000 N): \[ \text{Resultant force} = 1000\, \text{N} – 600\, \text{N} = 400\, \text{N} \text{ downwards} \]
Question 30 (Subtopic: P1.6)
Electricity is generated in power stations. Many power stations use steam to drive turbines.
Which type of power station does not use steam?
A) chemical energy (fuel) power stations
B) geothermal energy power stations
C) hydroelectric energy power stations
D) nuclear energy power stations
▶️Answer/Explanation
Answer: C) hydroelectric energy power stations
Explanation: Hydroelectric power stations generate electricity by using the kinetic energy of flowing water to drive turbines, without the need for steam.
Question 31 (Subtopic: P2.3)
An electric kettle is switched on, and the temperature of the water in it increases to 60°C. What is the main method of heat transfer within the water?
A) boiling
B) conduction
C) convection
D) radiation
▶️Answer/Explanation
Answer: C) convection
Explanation: In liquids, heat is primarily transferred through convection, where warmer water rises and cooler water sinks, creating a circulating current.
Question 32 (Subtopic: P3.1)
A tank contains water. A wave is produced and travels across the surface of the water.
What is the maximum height of the water as the wave passes compared with the original level of the water?
A) the amplitude
B) the frequency
C) the speed
D) the wavelength
▶️Answer/Explanation
Answer: A) the amplitude
Explanation: The amplitude of a wave is the maximum displacement of the wave from its rest position. In this case, it is the maximum height of the water wave.
Question 33 (Subtopic: P3.2)
The diagram shows light passing through a thin converging lens.
What is the distance X?
A) the distance from the lens to an object
B) the focal length of the lens
C) the principal focus of the lens
D) the wavelength of the light
▶️Answer/Explanation
Answer: B) the focal length of the lens
Explanation: The distance X is the focal length of the lens, which is the distance from the lens to the principal focus where parallel rays of light converge.
Question 34 (Subtopic: P3.4)
A person stands 320 m away from a cliff and shouts. He hears an echo from the cliff 2.0 s later. What is the speed of sound in the air?
A) 160 m/s
B) 300 m/s
C) 320 m/s
D) 640 m/s
▶️Answer/Explanation
Answer: C) 320 m/s
Explanation: The speed of sound is calculated using the formula: \[ \text{Speed} = \frac{\text{Distance}}{\text{Time}} \] The sound travels to the cliff and back, so the total distance is \( 2 \times 320\, \text{m} = 640\, \text{m} \). The time taken is 2.0 s, so: \[ \text{Speed} = \frac{640\, \text{m}}{2.0\, \text{s}} = 320\, \text{m/s} \]
Question 35 (Subtopic: P4.2)
What is the unit for electromotive force (e.m.f.)?
A) ampere
B) ohm
C) newton
D) volt
▶️Answer/Explanation
Answer: D) volt
Explanation: Electromotive force (e.m.f.) is measured in volts (V), which is the unit for electrical potential difference.
Question 36 (Subtopic: P4.3)
A 3.0 Ω resistor and a 6.0 Ω resistor are connected to a power supply as shown.
What is the combined resistance of the two resistors?
A) 2.0 Ω
B) 4.5 Ω
C) 9.0 Ω
D) 18 Ω
▶️Answer/Explanation
Answer: C) 9.0 Ω
Explanation: When resistors are connected in series, their resistances add up: \[ \text{Total resistance} = 3.0\, \Omega + 6.0\, \Omega = 9.0\, \Omega \]
Question 37 (Subtopic: P4.4)
An electric kettle is designed so that the usual current in its heater is 9.0 A. The owner of the kettle fits the plug with a fuse rated at 3 A. What happens when the kettle is filled with water and switched on?
A) The current in the circuit increases to greater than 9.0 A.
B) The fuse blows immediately and the kettle fails to operate.
C) The water reaches boiling point more quickly due to an increase in the voltage.
D) The water reaches boiling point more slowly due to a decrease in the current.
▶️Answer/Explanation
Answer: B) The fuse blows immediately and the kettle fails to operate.
Explanation: The fuse is rated at 3 A, which is lower than the usual current of 9.0 A. When the kettle is switched on, the current exceeds the fuse rating, causing the fuse to blow and the kettle to fail to operate.
Question 38 (Subtopic: P4.5)
A solenoid carrying a current produces a magnetic field. Which diagram shows the magnetic field pattern?
▶️Answer/Explanation
Answer: D) Diagram D
Explanation: A solenoid carrying a current produces a magnetic field with field lines running parallel to the axis of the solenoid, as shown in Diagram D.
Question 39 (Subtopic: P5.2)
Which type of radiation has the greatest ionising effect?
A) infrared rays
B) α-particles
C) β-particles
D) γ-rays
▶️Answer/Explanation
Answer: B) α-particles
Explanation: Alpha particles (α-particles) have the greatest ionising effect because they are large and carry a double positive charge, allowing them to interact strongly with matter.
Question 40 (Subtopic: P5.2)
The graph shows how the rate of emission from a radioactive sample changes with time.
What is the half-life of this sample?
A) 40 minutes
B) 2.0 years
C) 5.0 years
D) 10 years
▶️Answer/Explanation
Answer: B) 2.0 years
Explanation: The half-life is the time taken for the rate of emission to halve. From the graph, the rate decreases from 80 emissions/minute to 40 emissions/minute in 2.0 years, so the half-life is 2.0 years.