Question 1 (B1.1)
Which characteristic of living organisms is correctly matched to the description?
| characteristic | description | |
|---|---|---|
| A | excretion | the removal from organisms of the waste products of metabolism |
| B | nutrition | the chemical reactions in cells that break down nutrient molecules and release energy for metabolism |
| C | respiration | the taking in of materials for energy, growth and development |
| D | sensitivity | the action by an organism or part of an organism causing a change of position or place |
▶️Answer/Explanation
Answer: A
Explanation: Excretion is correctly defined as the removal of metabolic waste products. Option B describes respiration, C describes nutrition, and D describes movement rather than sensitivity.
Question 2 (B3.1)
Which row correctly describes the diffusion of molecules from P to Q?
| P | Q | movement | |
|---|---|---|---|
| A | higher concentration | lower concentration | down a concentration gradient |
| B | higher concentration | lower concentration | up a concentration gradient |
| C | lower concentration | higher concentration | down a concentration gradient |
| D | lower concentration | higher concentration | up a concentration gradient |
▶️Answer/Explanation
Answer: A
Explanation: Diffusion is the net movement of particles from a region of higher concentration to lower concentration (down the concentration gradient). Movement from lower to higher concentration would require energy (active transport).
Question 3 (B4.1)
Which chemical element is found in proteins, but not in carbohydrates or fats?
A carbon
B hydrogen
C oxygen
D nitrogen
▶️Answer/Explanation
Answer: D
Explanation: Nitrogen is present in proteins (in amino groups) but absent in carbohydrates and fats, which only contain carbon, hydrogen and oxygen.
Question 4 (B5.1)
An investigation was carried out to see the effect of temperature on how quickly the enzyme amylase breaks down starch to sugar.
Which labels should be used for the axes and what has happened at point Z?
| x-axis | y-axis | what has happened at Z | |
|---|---|---|---|
| A | rate of breakdown of starch | temperature | enzyme is denatured |
| B | temperature | time taken to break down starch | enzyme is used up |
| C | temperature | rate of break down of starch | enzyme is denatured |
| D | time taken to break down starch | temperature | enzyme is used up |
▶️Answer/Explanation
Answer: C
Explanation: The independent variable (temperature) should be on the x-axis, with the dependent variable (rate of reaction) on the y-axis. Point Z represents the temperature where the enzyme denatures, causing a sharp drop in reaction rate.
Question 5 (B6.1)
A farmer noticed that the older leaves of his maize plant were becoming yellow between the veins.
What is the plant lacking?
A carbon dioxide
B magnesium ions
C sunlight
D water
▶️Answer/Explanation
Answer: B
Explanation: Yellowing between veins (interveinal chlorosis) in older leaves is a classic symptom of magnesium deficiency, as magnesium is needed to make chlorophyll and is mobile within the plant.
Question 6 (B7.1)
Which disease is caused by a diet that is low in protein?
A coronary heart disease
B kwashiorkor
C rickets
D scurvy
▶️Answer/Explanation
Answer: B
Explanation: Kwashiorkor is a protein deficiency disease, while rickets is caused by vitamin D deficiency, scurvy by vitamin C deficiency, and coronary heart disease by various factors including high fat diet.
Question 7 (B9.4)
Which component is needed for blood to clot?
A hormones
B platelets
C red blood cells
D white blood cells
▶️Answer/Explanation
Answer: B
Explanation: Platelets are essential for blood clotting (haemostasis). They form a plug at the injury site and release chemicals that initiate the clotting cascade.
Question 8 (B11.1)
During vigorous exercise there is an increase in the rate of breathing.
What causes the increase in the rate of breathing?
A a decrease in the adrenaline concentration in the blood
B a decrease in the lactic acid concentration in the blood
C an increase in the alcohol concentration in the blood
D an increase in the carbon dioxide concentration in the blood
▶️Answer/Explanation
Answer: D
Explanation: Increased CO₂ concentration in the blood (detected by chemoreceptors) is the main stimulus for increased breathing rate during exercise, as the body needs to remove excess CO₂ and obtain more oxygen.
Question 9 (B13.1)
What occurs when our eyes look from a near object in dim light to a distant object in bright light?
A Pupils constrict and lenses become thinner.
B Pupils constrict and lenses become fatter.
C Pupils dilate and lenses become thinner.
D Pupils dilate and lenses become fatter.
▶️Answer/Explanation
Answer: A
Explanation: In bright light, pupils constrict to reduce light entry. For distant objects, ciliary muscles relax, making the lens thinner (less convex) to focus the parallel light rays.
Question 10 (B15.3)
The diagram shows a section through an insect-pollinated flower.
When pollination occurs, where must the pollen grains reach?
▶️Answer/Explanation
Answer: B
Explanation: For successful pollination, pollen must reach the stigma (B), which is the receptive surface of the female reproductive part where pollen germination occurs.
Question 11 (B16.1)
Which row about human cells is correct?
▶️Answer/Explanation
Answer: D
Explanation: In humans, gametes (sperm or egg cells) are haploid (containing one set of chromosomes) and have 23 chromosomes. Body cells are diploid (containing two sets of chromosomes) and have 46 chromosomes. Therefore, option D is the only correct statement.
Question 12 (B18.2)
In a food chain, what do all living organisms get from their food?
A. a supply of water
B. oxygen for respiration
C. protection from disease
D. the energy they need
▶️Answer/Explanation
Answer: D
Explanation: All living organisms obtain energy from their food, which is used for growth, movement, reproduction, and other life processes. While some organisms may get water or other nutrients from food, the universal requirement is energy.
Question 13 (B19.1)
What decreases as a result of eutrophication?
A. aerobic respiration by decomposers
B. decomposition of dead producers
C. dissolved oxygen in the water
D. growth of producers
▶️Answer/Explanation
Answer: C
Explanation: Eutrophication leads to excessive growth of algae (producers), which then die and are decomposed by bacteria. The decomposition process consumes oxygen, leading to a decrease in dissolved oxygen in the water, which can suffocate aquatic life.
Question 14 (C6.1)
Two substances, X and Y, are heated and then cooled. The observations are shown:
Which type of change occurs when X and Y are heated?
▶️Answer/Explanation
Answer: B
Explanation: Substance X undergoes a chemical change (color change indicates new substance formed), while substance Y undergoes a physical change (sublimation and recondensation of the same substance).
Question 15 (C2.3)
Why do isotopes of the same element have the same chemical properties?
A. They have a different number of protons and a different number of outer shell electrons.
B. They have a different number of protons and the same number of outer shell electrons.
C. They have the same number of protons and a different number of outer shell electrons.
D. They have the same number of protons and the same number of outer shell electrons.
▶️Answer/Explanation
Answer: D
Explanation: Isotopes have the same number of protons (same atomic number) and same electron configuration (same number of outer shell electrons), which determines chemical properties. They differ only in neutron number.
Question 16 (C2.6)
Diamond and graphite are different forms of the element carbon. Graphite conducts electricity. Which statement explains why diamond does not conduct electricity?
A. All of the atoms in diamond are arranged tetrahedrally.
B. All of the bond lengths in diamond are the same.
C. All of the bonds in diamond are single bonds.
D. All of the outer shell electrons in diamond are held in covalent bonds.
▶️Answer/Explanation
Answer: D
Explanation: In diamond, all four outer electrons of each carbon atom are involved in strong covalent bonds, leaving no delocalized electrons to conduct electricity, unlike graphite which has delocalized electrons between layers.
Question 17 (C4.1)
What is the electrolyte that is used when a nickel spoon is electroplated with copper?
A. copper
B. copper sulfate solution
C. nickel sulfate solution
D. nickel
▶️Answer/Explanation
Answer: B
Explanation: Copper sulfate solution is used as the electrolyte because it contains Cu²⁺ ions that will be reduced and deposited onto the nickel spoon (cathode) during electroplating.
Question 18 (C5.1)
An acid is added to an alkali until the final solution is just neutral. The reaction is exothermic.
Which graph shows how the temperature changes as the acid is being added to the alkali?
▶️Answer/Explanation
Answer: C
Explanation: For an exothermic neutralization reaction, the temperature rises as acid is added until the equivalence point (neutralization), then levels off or decreases slightly as excess acid is added. Graph C shows this pattern.
Question 19 (C7.2)
Some properties of four oxides, W, X, Y and Z, are shown:
| property | W | X | Y | Z |
|---|---|---|---|---|
| reaction with acids | yes | no | no | yes |
| reaction with alkalis | no | yes | no | yes |
Which row classifies these oxides?
▶️Answer/Explanation
Answer: D
Explanation: W reacts with acids only (basic oxide), X reacts with alkalis only (acidic oxide), Y reacts with neither (neutral oxide), and Z reacts with both acids and alkalis (amphoteric oxide).
Question 20 (C7.3)
Hydrochloric acid and sodium hydroxide neutralize each other to form water and sodium chloride. Which method is used to make the solution crystallize?
A. chromatography
B. evaporation
C. filtration
D. fractional distillation
▶️Answer/Explanation
Answer: B
Explanation: Evaporation is used to crystallize sodium chloride from the neutralized solution by removing water, causing the salt to come out of solution as crystals.
Question 21 (C8.1)
Which statement about elements in the Periodic Table is correct?
A. Elements are arranged in mass number order.
B. The group number of an element is the same as the number of outer shell electrons.
C. The reactivity of elements in both Group I and Group VII increases down the group.
D. There is a change from non-metallic to metallic character from left to right across each period.
▶️Answer/Explanation
Answer: B
Explanation: The group number corresponds to the number of valence (outer shell) electrons for Groups I-VII. Option A is incorrect because elements are arranged by atomic number. Option C is wrong – Group VII reactivity decreases down the group. Option D is incorrect as metallic character decreases left to right across periods.
Question 22 (C9.4)
Samples of four different metals, L, M, N and O, are added to solutions of the metal chlorides. The table shows which metals react with the metal chlorides.
What is the order of reactivity?
▶️Answer/Explanation
Answer: C
Explanation: A more reactive metal can displace a less reactive one from its compound. N displaces all others (most reactive), M displaces L and O, O only displaces L, and L displaces none (least reactive). Therefore the reactivity order is N > M > O > L.
Question 23 (C9.2)
Some properties of aluminium are listed.
1. conducts electricity
2. malleable
3. resistant to corrosion
Which properties make aluminium suitable for use as food containers?
A. 1, 2 and 3
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
▶️Answer/Explanation
Answer: D
Explanation: For food containers, malleability (2) allows shaping into containers, and corrosion resistance (3) prevents contamination. Electrical conductivity (1) is irrelevant for food containers, eliminating options A, B and C.
Question 24 (C10.2)
Which processes lead to the formation of a greenhouse gas?
1. reaction of sodium with water
2. respiration
3. combustion of fossil fuels
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
▶️Answer/Explanation
Answer: C
Explanation: Respiration (2) and combustion (3) both produce CO₂, a greenhouse gas. Sodium reacting with water (1) produces hydrogen gas, which is not a greenhouse gas. Therefore only options containing 2 and 3 are correct.
Question 25 (C6.2)
Sulfuric acid is manufactured by the Contact process. Four reactions occur in this process. Which reaction requires a catalyst?
A. S + O₂ → SO₂
B. 2SO₂ + O₂ → 2SO₃
C. H₂SO₄ + SO₃ → H₂S₂O₇
D. H₂S₂O₇ + H₂O → 2H₂SO₄
▶️Answer/Explanation
Answer: B
Explanation: In the Contact process, the oxidation of SO₂ to SO₃ (reaction B) requires a vanadium(V) oxide catalyst to proceed at a practical rate. The other reactions occur readily without catalysts.
Question 26 (C11.5)
Three reactions are listed.
1. the addition of hydrogen to ethene
2. the addition of steam to ethene
3. the cracking of long chain alkanes
Which reactions produce molecules of a different homologous series from the reactant molecules?
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: All three reactions change the homologous series: (1) converts alkene to alkane, (2) converts alkene to alcohol, and (3) converts alkanes to alkenes (and possibly alkanes of different chain lengths). Therefore all options produce different homologous series.
Question 27 (C11.7)
Which diagram represents part of the structure of nylon?
▶️Answer/Explanation
Answer: A
Explanation: Nylon is a polyamide with characteristic -CO-NH- (amide) linkages in its polymer chain. Option A shows this amide linkage, while the others show polyethylene (B), polyethene (C) and possibly polystyrene (D) structures.
Question 28 (P1.5.1)
A spring that obeys Hooke’s law has an unstretched length of 5.0 cm. A load of weight 0.50 N is hung from the spring and the length of the spring becomes 10.0 cm.
The load is replaced with a new load and the length of the spring becomes 15.0 cm. The spring has not passed its limit of proportionality.
What is the weight of the new load?
A. 0.50 N
B. 0.75 N
C. 1.0 N
D. 1.5 N
▶️Answer/Explanation
Answer: C
Explanation: Using Hooke’s law (F = kx): First extension = 10-5 = 5cm with 0.5N, so k = 0.5/5 = 0.1 N/cm. Second extension = 15-5 = 10cm, so F = 0.1 × 10 = 1.0 N. The force is proportional to extension while within the limit of proportionality.
Question 29 (P1.6.1)
An object X with mass 2.0 kg is moving with a speed of 4.0 m/s. Which object has kinetic energy equal to that of object X?
| Mass of object (kg) | Speed of object (m/s) | |
|---|---|---|
| A | 0.50 | 16 |
| B | 1.0 | 8.0 |
| C | 8.0 | 2.0 |
| D | 16 | 1.0 |
▶️Answer/Explanation
Answer: C
Explanation: KE = ½mv². For X: KE = ½×2×4² = 16J. Calculate KE for each option: A=64J, B=32J, C=16J, D=8J. Only option C has the same kinetic energy as object X.
Question 30 (P1.6.4)
What are the units of work and power?
| work | power | |
|---|---|---|
| A | joule | joule |
| B | joule | watt |
| C | watt | joule |
| D | watt | watt |
▶️Answer/Explanation
Answer: B
Explanation: Work is energy transferred, measured in joules. Power is the rate of doing work (energy/time), measured in watts (joules/second). Therefore the correct combination is joule for work and watt for power.
Question 31 (P2.2.2)
When evaporation occurs, molecules escape from the surface of a liquid.
Which molecules escape, and what happens to the average speed of the molecules remaining in the liquid?
| escaping molecules | average speed of remaining molecules | |
|---|---|---|
| A | less energetic | decreases |
| B | less energetic | increases |
| C | more energetic | decreases |
| D | more energetic | increases |
▶️Answer/Explanation
Answer: C
Explanation: During evaporation, the more energetic molecules with higher kinetic energy escape from the liquid surface. This leaves behind molecules with lower average kinetic energy, resulting in a decrease in the average speed of the remaining molecules. This is why evaporation causes cooling of the liquid.
Question 32 (P2.3.3)
Two identical metal containers are painted. One is painted dull black and the other is painted shiny silver. They contain equal volumes of water and are placed outside on a sunny day.
The temperature of the water in the black container increases more quickly than the temperature of the water in the silver container.
Why does this happen?
A. The black container is the better absorber of radiation from the Sun.
B. The black container is the better conductor of heat.
C. The black container is the better emitter of radiation.
D. The black container is the better reflector of radiation from the Sun.
▶️Answer/Explanation
Answer: A
Explanation: Dull black surfaces are good absorbers of thermal radiation, while shiny silver surfaces are poor absorbers and good reflectors. Therefore, the black container absorbs more solar radiation, causing its water temperature to increase faster. The difference is due to absorption properties, not conduction or emission.
Question 33 (P3.1)
Diagram 1 represents a wave.
Which diagram represents a wave with twice the frequency and half the amplitude of the wave in diagram 1?
The scales are the same in all the diagrams.
▶️Answer/Explanation
Answer: B
Explanation: Twice the frequency means the wave should have half the wavelength (more waves in the same time period). Half the amplitude means the peaks and troughs should be half as high/deep as the original wave. Option B correctly shows both these modifications while maintaining the same wave shape.
Question 34 (P3.2.3)
In the diagrams, F is one principal focus of the converging lens.
Which diagram shows the lens being used as a magnifying glass?
▶️Answer/Explanation
Answer: A
Explanation: A converging lens acts as a magnifying glass when the object is placed between the lens and its focal point (F). This creates a virtual, upright, and magnified image on the same side as the object, which is shown in diagram A. The other options show different object positions resulting in different image types.
Question 35 (P3.4)
A sports field is next to a large school building. A student at the far side of the sports field sees a groundsman hit a pole with a hammer.
After the hammer hits the pole, the student hears two bangs.
Why does the student hear two bangs?
| first bang caused by | second bang caused by | |
|---|---|---|
| A | sound of hammer hitting pole | sound of pole hitting hammer |
| B | sound reaching the student’s left ear | sound reaching the student’s right ear |
| C | sound reaching student directly | sound reflected back from school building |
| D | sound reflected back from school building | sound reaching student directly |
▶️Answer/Explanation
Answer: C
Explanation: The student hears two bangs because sound travels both directly from the pole to the student and indirectly by reflecting off the school building. The direct sound arrives first as it travels a shorter distance, while the reflected sound takes a longer path and arrives slightly later, creating an echo effect.
Question 36 (P4.3)
In the circuit, component X is used to control the brightness of the lamp.
What is component X?
A. an ammeter
B. a fixed resistor
C. a fuse
D. a variable resistor
▶️Answer/Explanation
Answer: D
Explanation: A variable resistor (rheostat) can control the brightness of a lamp by varying the resistance in the circuit, which changes the current flowing through the lamp. Ammeters measure current but don’t control it, fixed resistors provide constant resistance, and fuses are safety devices that don’t adjust brightness.
Question 37 (P4.2.5)
There is a current of 3.0 A in a resistor. The potential difference across the resistor is 3.0 V.
How much electrical energy is transferred to other forms in 3.0 minutes?
A. 3.0 J
B. 9.0 J
C. 540 J
D. 1620 J
▶️Answer/Explanation
Answer: D
Explanation: Energy = Power × Time Power = Voltage × Current = 3.0V × 3.0A = 9.0W Time = 3.0 minutes = 180 seconds Energy = 9.0W × 180s = 1620J The electrical energy transferred is 1620 joules.
Question 38 (P4.5.2)
Which graph shows how the output voltage of an a.c. generator varies with time?
▶️Answer/Explanation
Answer: A
Explanation: An AC generator produces a voltage that varies sinusoidally with time, regularly alternating between positive and negative values. Graph A correctly shows this smooth, periodic variation. The other graphs show DC voltage (B), irregular AC (C), or pulsed DC (D), none of which represent standard AC generator output.
Question 39 (P4.5.6)
A transformer increases the voltage from a power station in order to transfer electricity along the 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
Explanation: Transformers increase voltage which decreases current (P=IV, power remains constant). Higher voltage transmission reduces energy loss as heat (I²R losses), making the system more efficient. Therefore, current decreases while efficiency increases.
Question 40 (P5.1)
There are three different isotopes of hydrogen.
Which statement about the nuclei of these three isotopes is correct?
A. They have different numbers of electrons.
B. They have the same number of nucleons.
C. They have the same number of neutrons.
D. They have the same number of protons.
▶️Answer/Explanation
Answer: D
Explanation: Isotopes of an element have the same number of protons (which defines the element) but different numbers of neutrons. Hydrogen-1 has 1 proton, hydrogen-2 (deuterium) has 1 proton and 1 neutron, hydrogen-3 (tritium) has 1 proton and 2 neutrons. All have 1 electron when neutral.