▶️ Answer/Explanation
The bladderwort detects a nearby swimming animal and traps it, showing sensitivity — the ability to detect and respond to a stimulus.
It then digests the trapped animal, absorbing nutrients from it, which shows nutrition — taking in materials for energy and growth.
No excretion or growth process is described in the diagram.
✅ Answer: (D)
It then digests the trapped animal, absorbing nutrients from it, which shows nutrition — taking in materials for energy and growth.
No excretion or growth process is described in the diagram.
✅ Answer: (D)
▶️ Answer/Explanation
Cell membrane and nucleus are present in both plant and animal cells.
Stomata are found on leaves, not inside individual cells.
Chloroplasts are only found in plant cells (and some other photosynthetic organisms), never in animal cells.
✅ Answer: (B)
Stomata are found on leaves, not inside individual cells.
Chloroplasts are only found in plant cells (and some other photosynthetic organisms), never in animal cells.
✅ Answer: (B)
▶️ Answer/Explanation
A purple colour with the biuret test confirms the presence of protein.
A white emulsion with the ethanol test confirms the presence of fat.
Iodine staying brown (not blue-black) shows starch is absent.
✅ Answer: (A)
A white emulsion with the ethanol test confirms the presence of fat.
Iodine staying brown (not blue-black) shows starch is absent.
✅ Answer: (A)
▶️ Answer/Explanation
The graph shows starch mass falling fastest (steepest decline) at \( 40\,^\circ\text{C} \), meaning amylase is breaking it down quickest at that temperature.
At \( 10\,^\circ\text{C} \) and \( 25\,^\circ\text{C} \) the enzyme has low kinetic energy so the reaction is slow.
At \( 70\,^\circ\text{C} \) the enzyme is denatured, so little or no starch is broken down.
✅ Answer: (C)
At \( 10\,^\circ\text{C} \) and \( 25\,^\circ\text{C} \) the enzyme has low kinetic energy so the reaction is slow.
At \( 70\,^\circ\text{C} \) the enzyme is denatured, so little or no starch is broken down.
✅ Answer: (C)
▶️ Answer/Explanation
Nitrate ions are absorbed from the soil by plant roots.
They are combined with sugars produced in photosynthesis to make amino acids, which are then built into proteins.
Nitrate ions are not needed to make starch, are not found in chloroplasts, and are not part of the cell sap.
✅ Answer: (D)
They are combined with sugars produced in photosynthesis to make amino acids, which are then built into proteins.
Nitrate ions are not needed to make starch, are not found in chloroplasts, and are not part of the cell sap.
✅ Answer: (D)
▶️ Answer/Explanation
Chemical digestion breaks large insoluble molecules down into small, soluble molecules using enzymes.
These small molecules can then be absorbed into the blood through the wall of the small intestine.
Breaking food into smaller pieces without chemical change is physical digestion (statement 1), and chemical digestion never makes molecules larger (statement 2), so only 3 and 4 are correct.
✅ Answer: (D)
These small molecules can then be absorbed into the blood through the wall of the small intestine.
Breaking food into smaller pieces without chemical change is physical digestion (statement 1), and chemical digestion never makes molecules larger (statement 2), so only 3 and 4 are correct.
✅ Answer: (D)
▶️ Answer/Explanation
The pulmonary vein carries oxygenated blood from the lungs back to the heart.
Veins carry blood towards the heart, so the correct vessel is the one with its arrow pointing from the lungs into the heart.
This corresponds to vessel B in the diagram.
✅ Answer: (B)
Veins carry blood towards the heart, so the correct vessel is the one with its arrow pointing from the lungs into the heart.
This corresponds to vessel B in the diagram.
✅ Answer: (B)
▶️ Answer/Explanation
Respiration is the chemical reaction in cells that breaks down nutrient molecules and releases energy.
This released energy is used for processes including maintaining a constant body temperature.
Homeostasis is the overall regulation process, photosynthesis makes food in plants, and sweating cools the body rather than providing energy.
✅ Answer: (C)
This released energy is used for processes including maintaining a constant body temperature.
Homeostasis is the overall regulation process, photosynthesis makes food in plants, and sweating cools the body rather than providing energy.
✅ Answer: (C)
▶️ Answer/Explanation
Adrenaline is released in “fight or flight” situations and causes an increase in heart rate.
On the graph, this corresponds to the point where the pulse rate begins to rise sharply, which is point A.
At the other points the pulse rate is either already elevated, falling, or steady, not just beginning to increase.
✅ Answer: (A)
On the graph, this corresponds to the point where the pulse rate begins to rise sharply, which is point A.
At the other points the pulse rate is either already elevated, falling, or steady, not just beginning to increase.
✅ Answer: (A)
▶️ Answer/Explanation
The testes are the site of sperm (male gamete) production.
The fetus develops in the uterus (not the cervix), the ovary releases the female gamete (not the oviduct), and it is glands such as the prostate — not the sperm duct itself — that secrete the fluids of semen.
Only the testes-function pairing is correct.
✅ Answer: (D)
The fetus develops in the uterus (not the cervix), the ovary releases the female gamete (not the oviduct), and it is glands such as the prostate — not the sperm duct itself — that secrete the fluids of semen.
Only the testes-function pairing is correct.
✅ Answer: (D)
▶️ Answer/Explanation
Genotype is defined as the genetic make-up of an organism in terms of the alleles it carries.
Phenotype instead describes the observable, physical features of an organism.
Dominant and recessive describe types of individual alleles, not the overall genetic make-up.
✅ Answer: (B)
Phenotype instead describes the observable, physical features of an organism.
Dominant and recessive describe types of individual alleles, not the overall genetic make-up.
✅ Answer: (B)
▶️ Answer/Explanation
Grass is the producer, the rabbit is the primary consumer, the fox is the secondary consumer, and the flea (feeding on the fox) is the tertiary consumer.
So statements A, B and C are all incorrect as worded.
The flea occupies the fourth position in the chain, making it the tertiary consumer.
✅ Answer: (D)
So statements A, B and C are all incorrect as worded.
The flea occupies the fourth position in the chain, making it the tertiary consumer.
✅ Answer: (D)
▶️ Answer/Explanation
Photosynthesis must show carbon dioxide moving from the air into plants, while respiration moves carbon dioxide from both plants and animals back into the air.
Feeding must show carbon moving from plants to animals only, in one direction.
Diagram A shows these three arrows going in the correct directions between air, plants and animals.
✅ Answer: (A)
Feeding must show carbon moving from plants to animals only, in one direction.
Diagram A shows these three arrows going in the correct directions between air, plants and animals.
✅ Answer: (A)
▶️ Answer/Explanation
Excess copper oxide is added so that all the sulfuric acid reacts, leaving unreacted solid copper oxide in the mixture.
Since copper oxide is insoluble, it can be separated from the aqueous copper sulfate solution by filtration, leaving the copper oxide as the residue.
Crystallisation would instead be used afterwards to obtain solid copper sulfate crystals from the filtrate.
✅ Answer: (D)
Since copper oxide is insoluble, it can be separated from the aqueous copper sulfate solution by filtration, leaving the copper oxide as the residue.
Crystallisation would instead be used afterwards to obtain solid copper sulfate crystals from the filtrate.
✅ Answer: (D)
▶️ Answer/Explanation
A molecule of a compound must contain two or more different types of atom joined together in fixed proportions.
Diagrams showing only one type of atom (whether single or joined) represent an element, not a compound.
Diagram B shows molecules made of two different atom types bonded together, representing a compound.
✅ Answer: (B)
Diagrams showing only one type of atom (whether single or joined) represent an element, not a compound.
Diagram B shows molecules made of two different atom types bonded together, representing a compound.
✅ Answer: (B)
▶️ Answer/Explanation
Group I alkali metals react vigorously with cold water to form a metal hydroxide and hydrogen gas.
The word equation is \( \text{potassium} + \text{water} \rightarrow \text{potassium hydroxide} + \text{hydrogen} \).
Potassium oxide and oxygen are not the products of this reaction.
✅ Answer: (A)
The word equation is \( \text{potassium} + \text{water} \rightarrow \text{potassium hydroxide} + \text{hydrogen} \).
Potassium oxide and oxygen are not the products of this reaction.
✅ Answer: (A)
▶️ Answer/Explanation
The cathode is the negative electrode, where positive ions gain electrons in a reduction reaction.
In dilute sulfuric acid, the positive ions present are hydrogen ions, \( \text{H}^+ \), which are reduced to form hydrogen gas at the cathode.
Oxygen forms at the anode instead, and sulfur dioxide and water vapour are not products of this electrolysis.
✅ Answer: (A)
In dilute sulfuric acid, the positive ions present are hydrogen ions, \( \text{H}^+ \), which are reduced to form hydrogen gas at the cathode.
Oxygen forms at the anode instead, and sulfur dioxide and water vapour are not products of this electrolysis.
✅ Answer: (A)
▶️ Answer/Explanation
In experiment X the final temperature is higher than the initial temperature, so thermal energy is being transferred to the surroundings — this is an exothermic reaction.
In experiment Y the initial and final temperatures shown are equal, indicating no net thermal energy transfer typical of an endothermic reaction pathway in this context.
This combination of exothermic X and endothermic Y matches row C of the table.
✅ Answer: (C)
In experiment Y the initial and final temperatures shown are equal, indicating no net thermal energy transfer typical of an endothermic reaction pathway in this context.
This combination of exothermic X and endothermic Y matches row C of the table.
✅ Answer: (C)
▶️ Answer/Explanation
Using smaller pieces of a solid increases its surface area, giving more area for particle collisions and increasing the reaction rate.
Catalysts do increase reaction rate, decreasing temperature slows a reaction down, and increasing concentration increases rate rather than decreasing it.
Only the statement about surface area is correct.
✅ Answer: (D)
Catalysts do increase reaction rate, decreasing temperature slows a reaction down, and increasing concentration increases rate rather than decreasing it.
Only the statement about surface area is correct.
✅ Answer: (D)
▶️ Answer/Explanation
In a redox reaction, one substance is oxidised (gains oxygen) while another is reduced (loses oxygen) at the same time.
Copper oxide loses its oxygen to become copper (reduction), while carbon gains oxygen to become carbon dioxide (oxidation).
The other equations are thermal decomposition or neutralisation reactions, not redox reactions.
✅ Answer: (C)
Copper oxide loses its oxygen to become copper (reduction), while carbon gains oxygen to become carbon dioxide (oxidation).
The other equations are thermal decomposition or neutralisation reactions, not redox reactions.
✅ Answer: (C)
▶️ Answer/Explanation
Potassium is a metal, so potassium oxide is a basic oxide, not an acidic oxide as listed.
Sulfur dioxide is a non-metal oxide, so it is an acidic oxide, not a basic oxide as listed.
Carbon dioxide is correctly acidic and sodium oxide is correctly basic, so only potassium oxide and sulfur dioxide are misplaced.
✅ Answer: (B)
Sulfur dioxide is a non-metal oxide, so it is an acidic oxide, not a basic oxide as listed.
Carbon dioxide is correctly acidic and sodium oxide is correctly basic, so only potassium oxide and sulfur dioxide are misplaced.
✅ Answer: (B)
▶️ Answer/Explanation
Copper is an element, it forms coloured ions (blue \( \text{Cu}^{2+} \) solutions), and its oxide, CuO, is a basic oxide.
Br2 and Na do not form coloured ions or basic oxides, and CO is a compound rather than an element.
Only copper satisfies all three overlapping properties.
✅ Answer: (C)
Br2 and Na do not form coloured ions or basic oxides, and CO is a compound rather than an element.
Only copper satisfies all three overlapping properties.
✅ Answer: (C)
▶️ Answer/Explanation
Group VIII noble gases have a full outer shell of electrons.
This stable electron arrangement means they have no tendency to gain, lose or share electrons, so they do not readily react.
Being gaseous or monatomic is a physical description, not the reason for their unreactivity.
✅ Answer: (D)
This stable electron arrangement means they have no tendency to gain, lose or share electrons, so they do not readily react.
Being gaseous or monatomic is a physical description, not the reason for their unreactivity.
✅ Answer: (D)
▶️ Answer/Explanation
A more reactive metal produces bubbles of hydrogen gas more vigorously and quickly with dilute acid.
Vigorous bubbling (metal 3) shows the most reactive metal, followed by steady bubbling (metal 4), then slow bubbling (metal 1), and no reaction (metal 2) shows the least reactive metal.
This gives the reactivity order 3 → 4 → 1 → 2.
✅ Answer: (D)
Vigorous bubbling (metal 3) shows the most reactive metal, followed by steady bubbling (metal 4), then slow bubbling (metal 1), and no reaction (metal 2) shows the least reactive metal.
This gives the reactivity order 3 → 4 → 1 → 2.
✅ Answer: (D)
▶️ Answer/Explanation
Adding water to anhydrous (white) copper(II) sulfate turns it blue, and hydrated (blue) copper(II) sulfate simply dissolves to give a blue solution.
Adding water to anhydrous (blue) cobalt(II) chloride turns it pink, and hydrated (pink) cobalt(II) chloride dissolves to give a pink solution.
So every watch-glass, once water is added, ends up as either a blue or a pink solution.
✅ Answer: (A)
Adding water to anhydrous (blue) cobalt(II) chloride turns it pink, and hydrated (pink) cobalt(II) chloride dissolves to give a pink solution.
So every watch-glass, once water is added, ends up as either a blue or a pink solution.
✅ Answer: (A)
▶️ Answer/Explanation
The naphtha fraction from fractional distillation of petroleum is mainly used as a chemical feedstock.
It provides the starting hydrocarbons used to manufacture other chemicals, such as through cracking.
Bottled gas, diesel fuel and road surfaces come from the refinery gas, diesel/gas oil, and bitumen fractions respectively, not naphtha.
✅ Answer: (B)
It provides the starting hydrocarbons used to manufacture other chemicals, such as through cracking.
Bottled gas, diesel fuel and road surfaces come from the refinery gas, diesel/gas oil, and bitumen fractions respectively, not naphtha.
✅ Answer: (B)
▶️ Answer/Explanation
An unsaturated compound contains one or more carbon–carbon bonds that are not single bonds.
Ethene, \( \text{C}_2\text{H}_4 \), contains a carbon–carbon double bond, so it is unsaturated.
Ethane, ethanol and methane all have only single carbon–carbon (or no carbon–carbon) bonds, making them saturated.
✅ Answer: (C)
Ethene, \( \text{C}_2\text{H}_4 \), contains a carbon–carbon double bond, so it is unsaturated.
Ethane, ethanol and methane all have only single carbon–carbon (or no carbon–carbon) bonds, making them saturated.
✅ Answer: (C)
▶️ Answer/Explanation
An object moving with constant speed covers equal distances in equal time intervals.
This is represented by a distance–time graph that is a straight line with a constant, non-zero gradient.
Graph A shows this straight-line pattern, matching constant speed motion.
✅ Answer: (A)
This is represented by a distance–time graph that is a straight line with a constant, non-zero gradient.
Graph A shows this straight-line pattern, matching constant speed motion.
✅ Answer: (A)
▶️ Answer/Explanation
An object moving at constant speed has no resultant force acting on it, so the downward weight W and upward air resistance R must be balanced.
Since the parachutist is still falling (not stationary), both W and R must have a real, non-zero value.
This means W is equal to R, and both are greater than zero.
✅ Answer: (B)
Since the parachutist is still falling (not stationary), both W and R must have a real, non-zero value.
This means W is equal to R, and both are greater than zero.
✅ Answer: (B)
▶️ Answer/Explanation
The moment of a force is calculated using \( \text{moment} = \text{force} \times \text{perpendicular distance from the pivot} \).
Force is measured in newtons (N) and distance is measured in metres (m), so the unit of moment is the product of these, N m.
N/kg is the unit for gravitational field strength, and N kg and N/m do not correspond to any standard physical quantity here.
✅ Answer: (C)
Force is measured in newtons (N) and distance is measured in metres (m), so the unit of moment is the product of these, N m.
N/kg is the unit for gravitational field strength, and N kg and N/m do not correspond to any standard physical quantity here.
✅ Answer: (C)
▶️ Answer/Explanation
Power is calculated using \( P = \dfrac{W}{t} \), where W is work done and t is time taken.
Increasing the work done (numerator) while decreasing the time taken (denominator) both act to increase the value of power.
Any option that decreases work done or increases time taken would decrease or fail to guarantee an increase in power.
✅ Answer: (C)
Increasing the work done (numerator) while decreasing the time taken (denominator) both act to increase the value of power.
Any option that decreases work done or increases time taken would decrease or fail to guarantee an increase in power.
✅ Answer: (C)
▶️ Answer/Explanation
Fossil fuels formed over millions of years from ancient organic matter and are being used up far faster than they can reform.
This makes chemical energy in fossil fuels a non-renewable energy resource.
Tides, geothermal heat and wind are all continuously replenished by natural processes, making them renewable resources.
✅ Answer: (A)
This makes chemical energy in fossil fuels a non-renewable energy resource.
Tides, geothermal heat and wind are all continuously replenished by natural processes, making them renewable resources.
✅ Answer: (A)
▶️ Answer/Explanation
Heating water lowers its density, so it rises above cooler, denser water rather than sinking to set up a convection current.
Since heater P is near the top, the water it heats simply stays above it and does not circulate down to warm the water below.
So only the water directly above heater P heats up quickly, reaching 60 °C in less time, while the water below stays cold.
✅ Answer: (D)
Since heater P is near the top, the water it heats simply stays above it and does not circulate down to warm the water below.
So only the water directly above heater P heats up quickly, reaching 60 °C in less time, while the water below stays cold.
✅ Answer: (D)
▶️ Answer/Explanation
Frequency is the number of wave crests (or complete oscillations) passing a fixed point per second.
Counting the crests passing Y over a known 30-second interval lets the student calculate this frequency directly.
Amplitude, wave speed and wavelength all require additional measurements (such as distance) that are not given here.
✅ Answer: (B)
Counting the crests passing Y over a known 30-second interval lets the student calculate this frequency directly.
Amplitude, wave speed and wavelength all require additional measurements (such as distance) that are not given here.
✅ Answer: (B)
▶️ Answer/Explanation
A quieter sound has a smaller amplitude, while a higher pitch has a shorter wavelength (more oscillations in the same time, i.e. a higher frequency).
The graph needed must show a smaller peak height than the original combined with more wave cycles squeezed into the same time period.
Graph D is the only one drawn to scale showing both a reduced amplitude and an increased frequency compared with the original.
✅ Answer: (D)
The graph needed must show a smaller peak height than the original combined with more wave cycles squeezed into the same time period.
Graph D is the only one drawn to scale showing both a reduced amplitude and an increased frequency compared with the original.
✅ Answer: (D)
▶️ Answer/Explanation
Magnetic field lines always point in the direction a free N pole would move if placed at that point, meaning they run from the N pole into the S pole outside the magnet.
So field lines must curve into (point towards) the S pole, and the lines are closer together (denser) nearer the pole where the field is strongest.
Diagram C correctly shows field lines curving into the S pole with the arrows pointing inward.
✅ Answer: (C)
So field lines must curve into (point towards) the S pole, and the lines are closer together (denser) nearer the pole where the field is strongest.
Diagram C correctly shows field lines curving into the S pole with the arrows pointing inward.
✅ Answer: (C)
▶️ Answer/Explanation
In series, resistances simply add together: \( R_{\text{total}} = 2.0 + 3.0 = 5.0\,\Omega \).
Using \( I = \dfrac{V}{R} \), the current is \( I = \dfrac{10}{5.0} = 2.0\,\text{A} \).
The same current flows through every component in a series circuit.
✅ Answer: (B)
Using \( I = \dfrac{V}{R} \), the current is \( I = \dfrac{10}{5.0} = 2.0\,\text{A} \).
The same current flows through every component in a series circuit.
✅ Answer: (B)
▶️ Answer/Explanation
A fuse protects a circuit by melting and breaking the circuit if the current becomes dangerously high, preventing overheating and fire — it does not maintain a constant current.
The fuse rating must be just above the normal operating current of 10 A, so a 13 A fuse is suitable (a 9 A fuse would blow immediately during normal use).
This matches “protects from overheating” with a 13 A rating.
✅ Answer: (D)
The fuse rating must be just above the normal operating current of 10 A, so a 13 A fuse is suitable (a 9 A fuse would blow immediately during normal use).
This matches “protects from overheating” with a 13 A rating.
✅ Answer: (D)
▶️ Answer/Explanation
The proton number (bottom number) is the number of protons, which is 79 for gold.
The nucleon number (top number) is the total number of protons and neutrons: \( 79 + 118 = 197 \).
So the correct nuclide symbol is \( ^{197}_{79}\text{Au} \), with 197 on top and 79 on the bottom.
✅ Answer: (D)
The nucleon number (top number) is the total number of protons and neutrons: \( 79 + 118 = 197 \).
So the correct nuclide symbol is \( ^{197}_{79}\text{Au} \), with 197 on top and 79 on the bottom.
✅ Answer: (D)
▶️ Answer/Explanation
1290 years is exactly \( \dfrac{1290}{430} = 3 \) half-lives.
The count rate halves with each half-life: \( 36\,000 \rightarrow 18\,000 \rightarrow 9000 \rightarrow 4500 \).
After 3 half-lives, the count rate is 4500 counts per minute.
✅ Answer: (A)
The count rate halves with each half-life: \( 36\,000 \rightarrow 18\,000 \rightarrow 9000 \rightarrow 4500 \).
After 3 half-lives, the count rate is 4500 counts per minute.
✅ Answer: (A)