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13+ · Science

CE.S-T14 Science: Full Practice Paper 14

ISEB COMMON ENTRANCE CE.S-T14 · Calculator allowed · about 60 minutes

Total Marks

Name: _______________________________ Date: ____ / ____ / ______

Answer ALL questions. Show all your working.

Which type of blood cell is mainly responsible for clotting the blood at the site of a wound?

A) Red blood cells
B) White blood cells
C) Platelets
D) Plasma

(Total for Question 1 is 1 mark)

In which state of matter are the particles arranged in a random pattern, touching their neighbours, and moving quickly in all directions, without being held in fixed positions?

A) Solid
B) Liquid
C) Gas
D) Plasma

(Total for Question 2 is 1 mark)

Which unit is used to measure power, the rate at which energy is transferred?

A) Joule
B) Newton
C) Watt
D) Volt

(Total for Question 3 is 1 mark)

Which gas do humans breathe out in a higher percentage than the air they breathe in?

A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen

(Total for Question 4 is 1 mark)

A student has a sample of salty water and wants to collect pure water from it, leaving the dissolved salt behind. Which separation method should the student use?

A) Filtration
B) Evaporation
C) Distillation
D) Sieving

(Total for Question 5 is 1 mark)

Which unit is used to measure electrical resistance?

A) Amp
B) Volt
C) Ohm
D) Watt

(Total for Question 6 is 1 mark)

Complete the two missing words in these sentences about the human skeleton and joints.

(a)The point where two or more bones meet, allowing movement to take place, is called a ______.(1)

(b)The tough tissue that connects a muscle to a bone, so that when the muscle contracts it pulls on the bone, is called a ______.(1)

(Total for Question 7 is 2 marks)

Complete the two missing words in these sentences about changes of state.

(a)The change of state when a liquid turns into a gas at its boiling point is called ______.(1)

(b)The change of state when a gas turns into a liquid as it cools is called ______.(1)

(Total for Question 8 is 2 marks)

Answer these questions about circuit diagram symbols.

(a)In a circuit diagram, which single component is usually drawn as a circle with a small cross inside it?(1)

(b)Which component is usually drawn as two parallel lines of different lengths, one longer than the other?(1)

(Total for Question 9 is 2 marks)

Meera investigates whether the amount of time a hamster spends running on its exercise wheel each day affects how much food it eats that day. She uses a sensor to record the total time the wheel spins each day, and weighs the food eaten by the hamster each day.

(a)State the independent variable in Meera's investigation.(1)

(b)State the dependent variable in Meera's investigation.(1)

(Total for Question 10 is 2 marks)

Complete the missing salt name produced in each acid-base neutralisation reaction below.

(a)Nitric acid + potassium hydroxide -> potassium ______ + water(1)

(b)Sulfuric acid + copper oxide -> copper ______ + water(1)

(c)Hydrochloric acid + magnesium oxide -> magnesium ______ + water(1)

(Total for Question 11 is 3 marks)

A wheelbarrow has its wheel acting as a pivot at the front. A heavy load is placed in the barrow close to the wheel, and the gardener applies an upward effort force at the handles, far from the wheel. Explain why it is much easier to lift a heavy load using a wheelbarrow than to lift the same load directly by hand, referring to the pivot and the perpendicular distances involved.

(Total for Question 12 is 3 marks)

Explain, using the 'lock and key' model, how the shape of an enzyme's active site allows it to break down one specific substrate.

(Total for Question 13 is 3 marks)

Aliyah investigates how the surface area of calcium carbonate affects its rate of reaction with dilute hydrochloric acid. She places a conical flask containing 50 cm3 of dilute hydrochloric acid on a mass balance, then adds 5 g of calcium carbonate, either as large lumps or as a fine powder, and records the total mass of the flask and its contents every 30 seconds. The flask is left open, without a bung.

(a)Explain why the total mass recorded on the balance decreases during the reaction.(1)

(b)Predict whether the powder or the lumps would show the greater decrease in mass in the first 30 seconds, and explain why.(1)

(c)Suggest one variable, other than the mass of calcium carbonate, that Aliyah must keep the same for this to be a fair test.(1)

(Total for Question 14 is 3 marks)

A student sees a flash of lightning, then hears the rumble of thunder 6 seconds later. The speed of sound in air is 340 m/s.

(a)Calculate the distance between the student and the lightning strike, using distance = speed x time.(1)

(b)Explain why the student sees the flash of lightning before hearing the thunder, even though they happen at the same time.(1)

(c)State what would happen to the time delay between the flash and the thunder if the storm moved closer to the student, and explain why.(1)

(Total for Question 15 is 3 marks)

Name the type of pathogen (disease-causing microorganism) responsible for causing each of these diseases.

(a)Salmonella food poisoning.(1)

(b)Chickenpox.(1)

(c)Ringworm, a skin infection.(1)

(Total for Question 16 is 3 marks)

Complete the sentences below about electron shells (energy levels).

(a)Electrons occupy shells around the nucleus of an atom. The innermost (first) shell can hold a maximum of ______ electrons.(1)

(b)The second shell can hold a maximum of ______ electrons before a third shell must start to fill.(1)

(c)An atom of oxygen has 8 electrons in total, arranged in shells as 2,6. State how many electrons are in the outer (outermost) shell of an oxygen atom.(1)

(Total for Question 17 is 3 marks)

A simple hydraulic car jack has a small piston, with a cross-sectional area of 2 cm2, connected by oil-filled tubing to a much larger piston, with a cross-sectional area of 20 cm2, which supports the car. Explain how pushing down with a small force on the small piston can lift a much heavier car resting on the large piston, referring to pressure.

(Total for Question 18 is 3 marks)

Jamal investigates how the concentration of sodium hydrogencarbonate solution (which provides extra dissolved carbon dioxide) affects the rate of photosynthesis in a piece of pondweed. He places the pondweed in a beaker of the solution, with a lamp positioned at a fixed distance and brightness, and counts the number of bubbles of gas released by the pondweed in one minute, at each of four different sodium hydrogencarbonate concentrations.

Concentration of sodium hydrogencarbonate solution (%): 0	0.5	1.0	1.5
Bubbles counted per minute: 4	22	38	39

(a)Identify the independent variable and the dependent variable in this investigation.(1)

(b)Describe the pattern shown by the results.(1)

(c)Explain why increasing the carbon dioxide available to the pondweed increases its rate of photosynthesis, up to a point.(1)

(d)Suggest one factor, other than carbon dioxide concentration, that might now be limiting the rate of photosynthesis between 1.0% and 1.5%, keeping the number of bubbles almost constant.(1)

(Total for Question 19 is 4 marks)

Isla carries out flame tests on four unknown metal salts, W, X, Y and Z. She dips a clean wire loop into each salt in turn and holds it in a blue Bunsen flame, recording the colour produced.

Salt: W	X	Y	Z
Flame colour: Lilac (purple)	Brick-red	Persistent orange-yellow	Blue-green

Reference key: lithium ions = red flame; sodium ions = persistent orange-yellow flame; potassium ions = lilac flame; calcium ions = brick-red flame; copper ions = blue-green flame.

(a)Using the key, identify the metal ion present in salt W.(1)

(b)Using the key, identify the metal ion present in salt Z.(1)

(c)Explain why a flame test is a useful way to help identify an unknown metal compound.(1)

(d)Suggest one reason why the flame test result for salt Y might be unreliable if salt Y were actually a mixture containing sodium ions and a small amount of another metal ion.(1)

(Total for Question 20 is 4 marks)

Deja investigates how the diameter (thickness) of a wire affects its resistance. She uses four wires made from the same metal, all cut to the same length, but with different diameters. She connects each wire in turn into a circuit with a battery, an ammeter and a voltmeter, and calculates the resistance of each wire using resistance = potential difference / current.

Diameter of wire (mm): 0.2	0.4	0.6	0.8
Resistance (ohms): 8.0	2.1	1.0	0.6

(a)Identify the independent variable and the dependent variable in this investigation.(1)

(b)Describe the pattern shown by the results.(1)

(c)Explain, in terms of the flow of electrons, why a thicker wire has a lower resistance than a thinner wire of the same length and material.(1)

(d)Name one variable, other than diameter, that Deja must keep the same for this to be a fair test.(1)

(Total for Question 21 is 4 marks)

Explain how root hair cells in a plant's roots are adapted for the efficient absorption of water and mineral ions from the soil.

(Total for Question 22 is 4 marks)

Explain, in terms of electron transfer, how a sodium atom and a chlorine atom react to form the ionic compound sodium chloride.

(Total for Question 23 is 4 marks)

Explain how a pinhole camera forms an inverted (upside-down) image of an object, referring to the way light travels.

(Total for Question 24 is 4 marks)

Ellie's class investigates whether background noise affects reaction time. Using an online reaction-time test, where a colour appears on screen and the volunteer clicks as fast as possible, each of ten volunteers completes the test three times under each of four conditions, and the mean reaction time for the group is calculated for each condition.

Condition: Silence	Quiet music	Loud music	People talking
Mean reaction time (ms): 210	215	260	310

(a)Identify the independent variable and the dependent variable in this investigation.(1)

(b)Describe the pattern shown by the results.(1)

(c)Suggest one reason why testing each volunteer three times under each condition, and using the group mean, improves the reliability of the results.(1)

(d)Explain, in terms of the brain processing information, why more background noise might slow down a person's reaction time.(1)

(Total for Question 25 is 4 marks)

Iron is extracted from iron oxide (Fe2O3) in a blast furnace, using carbon monoxide gas: Fe2O3 + 3CO -> 2Fe + 3CO2. Explain, in terms of oxygen, which substance is reduced and which substance is oxidised in this reaction, and explain why carbon monoxide is described as a reducing agent.

(Total for Question 26 is 4 marks)

A shot putter lifts a 4 kg shot (a heavy metal ball) above her shoulder to a height of 1.8 m before throwing it forward. (Gravitational field strength, g = 10 N/kg)

(a)Calculate the gravitational potential energy (GPE) the shot gains as it is lifted to this height, using GPE = mass x gravitational field strength x height.(2)

(b)State the name of the energy store that increases as the shot falls from this height back down towards the ground after being thrown, and state where this energy came from.(1)

(c)Suggest one reason why, in practice, not all of the 72 J of gravitational potential energy will have been transferred to kinetic energy by the time the shot lands on the ground.(1)

(Total for Question 27 is 4 marks)

Describe a test, including the positive result, that would show a food sample contains: starch; a reducing sugar (such as glucose); and protein.

(a)Starch(1)

(b)A reducing sugar (such as glucose)(1)

(c)Protein(1)

(Total for Question 28 is 3 marks)

Reece investigates how the depth of water above a hole affects the pressure of the water leaving through that hole. He takes a tall plastic can, 25 cm high, with four small holes made down one side at different heights above the base. Keeping the can topped up to the very top with water throughout, he measures the horizontal distance travelled by the water jet from each hole before it lands.

Height of hole above the base of the can (cm): 5	10	15	20
Horizontal distance travelled by water jet (cm): 38	30	20	9

(a)Identify the independent variable and the dependent variable in this investigation.(1)

(b)Describe the pattern shown by the results.(1)

(c)Explain this pattern in terms of water pressure and depth.(1)

(d)Explain why it was important for Reece to keep the can topped up to the top throughout each measurement, rather than letting the water level fall as it drained.(1)

(Total for Question 29 is 4 marks)

A gardener wants to find out whether spraying a new organic pesticide reduces the number of aphids (greenfly) on rose bushes, and whether it affects the number of ladybirds (which feed on aphids) living in the garden. She chooses two similar gardens, each with the same number and variety of rose bush, in a similar sunny position. Garden A is sprayed with the pesticide once a week; Garden B is left unsprayed as a comparison. Each month for three months, she counts the mean number of aphids and ladybirds per rose bush in each garden.

Month: 1	2	3
Garden A (sprayed), mean aphids per bush: 40	15	5
Garden A (sprayed), mean ladybirds per bush: 6	3	1
Garden B (unsprayed), mean aphids per bush: 42	58	70
Garden B (unsprayed), mean ladybirds per bush: 5	9	14

(a)State two variables the gardener should keep the same between Garden A and Garden B, other than whether the pesticide is sprayed, to make this a fair comparison.(2)

(b)Describe what the data shows happened to the aphid population in each garden over the three months.(1)

(c)Explain, referring to the food chain between aphids and ladybirds, why the ladybird population also fell in Garden A, even though the pesticide was not sprayed directly onto the ladybirds.(1)

(d)Suggest one reason the gardener's pesticide, despite reducing aphid numbers, might still be considered harmful to the wider garden ecosystem.(1)

(e)Suggest one improvement to the investigation that would make its conclusion more reliable.(1)

(Total for Question 30 is 6 marks)

Mark scheme · CE.S-T14 Science: Full Practice Paper 14

Question 1

B1 C cao
Answer: C) Platelets

Question 2

B1 B cao
Answer: B) Liquid

Question 3

B1 C cao
Answer: C) Watt

Question 4

B1 B cao
Answer: B) Carbon dioxide

Question 5

B1 C cao
Answer: C) Distillation

Question 6

B1 C cao
Answer: C) Ohm

Question 7

(a) B1 joint cao
(a) Answer: Joint
(b) B1 tendon cao
(b) Answer: Tendon

Question 8

(a) B1 boiling cao
(a) Answer: Boiling
(b) B1 condensation cao
(b) Answer: Condensation

Question 9

(a) B1 a bulb/lamp cao
(a) Answer: A bulb (lamp).
(b) B1 a cell/battery cao
(b) Answer: A cell (battery).

Question 10

(a) B1 the time spent running on the wheel each day oe
(a) Answer: The amount of time the hamster spends running on its wheel each day.
(b) B1 the mass/amount of food eaten each day oe
(b) Answer: The mass of food the hamster eats each day.

Question 11

(a) B1 nitrate cao
(a) Answer: Nitrate
(b) B1 sulfate cao
(b) Answer: Sulfate
(c) B1 chloride cao
(c) Answer: Chloride

Question 12

B1 the wheel acts as a pivot, and the wheelbarrow works as a simple lever using the principle of moments oe
B1 the load acts at a short distance from the pivot, so it produces a relatively small turning effect (moment) oe
B1 the effort is applied at a much greater distance from the pivot, so a much smaller effort force is needed to produce a turning effect large enough to lift/balance the load oe
Answer: The wheel acts as a pivot; because the load is close to the pivot and the effort is applied far from the pivot, a much smaller effort force is needed to produce the same turning effect (moment) as lifting the load directly.

Question 13

B1 an enzyme has a region called the active site, which has a specific shape oe
B1 only a substrate molecule with a complementary (matching) shape can fit into the active site, like a key fitting into a lock oe
B1 this is why an enzyme is specific to one substrate (or a small group of similarly shaped substrates); a substrate with the wrong shape will not fit, so no reaction takes place oe
Answer: An enzyme's active site has a specific shape, and only a substrate with a matching (complementary) shape can fit into it, like a key fitting a lock; this is why each enzyme is specific to one particular substrate.

Question 14

(a) B1 carbon dioxide gas, a product of the reaction, escapes from the open flask into the air, so the mass lost is the mass of the escaping gas oe
(a) Answer: Carbon dioxide gas, produced by the reaction, escapes from the open flask into the air, so the balance records a decreasing mass.
(b) B1 the powder, because it has a much greater surface area for the same mass, exposing more particles to collide and react with the acid particles, giving a faster initial rate of reaction oe
(b) Answer: The powder would show the greater decrease in mass, because its much larger surface area allows more particles to collide and react with the acid at once, giving a faster reaction.
(c) B1 the volume and concentration of the hydrochloric acid used, or the temperature oe
(c) Answer: The volume and concentration of the hydrochloric acid (or the temperature).

Question 15

(a) B1 2040 m (accept 2.04 km) cao
(a) Answer: 2040 m (2.04 km)
(b) B1 light travels enormously faster than sound, so the light from the flash reaches the student almost instantly, while the sound takes noticeably longer oe
(b) Answer: Light travels much faster than sound, so the flash is seen almost instantly, while the sound takes several seconds to arrive.
(c) B1 the time delay would decrease/get shorter, because the sound has a shorter distance to travel to reach the student, so it takes less time oe
(c) Answer: The time delay would decrease, because the sound would have a shorter distance to travel, taking less time to reach the student.

Question 16

(a) B1 bacteria/bacterium cao
(a) Answer: Bacteria
(b) B1 virus cao
(b) Answer: Virus
(c) B1 fungus/fungi cao
(c) Answer: Fungus

Question 17

(a) B1 2 cao
(a) Answer: 2
(b) B1 8 cao
(b) Answer: 8
(c) B1 6 cao
(c) Answer: 6

Question 18

B1 pressure = force / area, and this pressure is transmitted equally through the liquid (oil) to every part of the connected system oe
B1 since the pressure at the small piston equals the pressure at the large piston, and the large piston has a much bigger area, force = pressure x area means it can exert a much greater force oe
B1 this means a small force pushing on the small piston can produce a much larger force at the large piston, which is enough to lift the heavy car oe
Answer: Pushing on the small piston creates a pressure that is transmitted equally through the oil to the large piston. Since force = pressure x area, and the large piston has a much bigger area, the same pressure produces a much larger force there, enough to lift the car.

Question 19

(a) B1 independent variable: concentration of sodium hydrogencarbonate solution; dependent variable: number of bubbles released per minute
(a) Answer: Independent variable: concentration of sodium hydrogencarbonate solution. Dependent variable: number of bubbles counted per minute.
(b) B1 as concentration increases from 0% to 1.0%, the number of bubbles per minute increases sharply, but between 1.0% and 1.5% the increase becomes very small (levels off) oe
(b) Answer: The number of bubbles per minute increases sharply as concentration rises from 0% to 1.0%, but barely increases further between 1.0% and 1.5%.
(c) B1 carbon dioxide is one of the raw materials (reactants) needed for photosynthesis, so when it was in short supply (a limiting factor), providing more of it allows the reaction to proceed faster, up to the point where something else becomes limiting oe
(c) Answer: Carbon dioxide is a raw material needed for photosynthesis, so increasing its supply, when it was limited, allows the reaction to speed up, until another factor becomes limiting.
(d) B1 light intensity (or temperature), since these were kept the same throughout the investigation oe
(d) Answer: Light intensity (or temperature), since both were kept constant throughout the investigation.

Question 20

(a) B1 potassium (ions) cao
(a) Answer: Potassium ions.
(b) B1 copper (ions) cao
(b) Answer: Copper ions.
(c) B1 each metal ion produces its own characteristic (different) flame colour, so seeing which colour is produced can show which metal ion is present in the unknown sample oe
(c) Answer: Each metal ion produces a characteristic flame colour, so the colour seen can reveal which metal ion is present in an unknown sample.
(d) B1 sodium produces a very strong, persistent orange-yellow flame that can mask (hide) the less intense colour of other metal ions present, making it hard to tell if another ion is also present oe
(d) Answer: Sodium's strong orange-yellow flame can mask the weaker colour produced by another metal ion present in the same sample.

Question 21

(a) B1 independent variable: diameter (thickness) of the wire; dependent variable: resistance of the wire
(a) Answer: Independent variable: diameter of the wire. Dependent variable: resistance of the wire.
(b) B1 as the diameter of the wire increases, the resistance decreases oe
(b) Answer: As the diameter of the wire increases, its resistance decreases.
(c) B1 a thicker wire gives electrons more space, and more possible pathways, to flow through, so they are less likely to collide with the metal ions, allowing current to flow more easily and giving a lower resistance oe
(c) Answer: A thicker wire gives electrons more space and more pathways to flow through, so they collide with the metal ions less often, allowing current to flow more easily and giving a lower resistance.
(d) B1 the length of the wire, or the material of the wire, or the temperature of the wire oe
(d) Answer: The length of the wire (or the material, or the temperature).

Question 22

B1 root hair cells have a long, thin extension (hair), which greatly increases their surface area in contact with the soil water oe
B1 this large surface area speeds up the rate at which water can be absorbed into the cell oe
B1 water is absorbed into the root hair cell by osmosis, since the concentration of water is usually higher in the soil than inside the cell oe
B1 mineral ions are absorbed by active transport, which allows ions to move into the cell against a concentration gradient (from a lower to a higher concentration), using energy from respiration oe
Answer: Root hair cells have a long, thin extension that greatly increases their surface area, speeding up water absorption by osmosis. Mineral ions, which may be at a lower concentration in the soil, are absorbed by active transport, using energy from respiration to move them against the concentration gradient.

Question 23

B1 a sodium atom has one electron in its outer shell, which it loses (transfers to the chlorine atom) oe
B1 the sodium atom becomes a positively charged ion, Na+, because it now has one more proton than electrons oe
B1 the chlorine atom gains this one electron, becoming a negatively charged ion, Cl-, because it now has one more electron than protons oe
B1 the oppositely charged Na+ and Cl- ions are strongly attracted to each other (electrostatic attraction), forming an ionic bond oe
Answer: A sodium atom loses its one outer electron to a chlorine atom. This forms a positive sodium ion (Na+) and a negative chloride ion (Cl-), which are strongly attracted to each other, forming an ionic bond.

Question 24

B1 light travels in straight lines (as rays) from every point on the object oe
B1 only one ray of light from each point on the object can pass through the tiny pinhole oe
B1 a ray from the top of the object travels in a straight line through the pinhole to the bottom of the screen, and a ray from the bottom of the object travels through to the top of the screen oe
B1 because rays from the top and bottom of the object cross over at the pinhole in this way, the image formed on the screen is inverted (upside down) compared with the object oe
Answer: Light travels in straight lines, and only one ray from each point on the object can pass through the tiny pinhole. Because rays from the top and bottom of the object cross over at the pinhole, the image formed on the screen is upside down.

Question 25

(a) B1 independent variable: the type/level of background noise; dependent variable: mean reaction time (ms)
(a) Answer: Independent variable: the type of background noise. Dependent variable: the mean reaction time.
(b) B1 as the background noise increases (from silence to talking), the mean reaction time increases (gets slower) oe
(b) Answer: As the background noise increases, the mean reaction time increases (gets slower).
(c) B1 repeating reduces the effect of any one unusually fast or slow result (random error), and averaging across many volunteers means the result is not just due to one person's individual reaction speed oe
(c) Answer: Repeating each test reduces the effect of any one unusually fast or slow result, and averaging across many volunteers means the result does not depend on just one person's reaction speed.
(d) B1 background noise is extra sensory information the brain must process, which competes for attention with the visual stimulus (the colour on the screen), interfering with (slowing down) the processing of the response along the nervous system oe
(d) Answer: Background noise is extra sensory information competing for the brain's attention alongside the visual stimulus, which interferes with and slows down the processing of the response.

Question 26

B1 iron oxide (Fe2O3) loses oxygen to form iron (Fe), so iron oxide is reduced oe
B1 carbon monoxide (CO) gains oxygen to form carbon dioxide (CO2), so carbon monoxide is oxidised oe
B1 reduction is the loss of oxygen from a substance, and oxidation is the gain of oxygen by a substance oe
B1 carbon monoxide is called a reducing agent because it removes oxygen from the iron oxide (causing the iron oxide to be reduced), while it is itself oxidised in the process oe
Answer: Iron oxide loses oxygen and is reduced to iron; carbon monoxide gains oxygen and is oxidised to carbon dioxide. Carbon monoxide is called a reducing agent because it removes oxygen from the iron oxide, causing its reduction.

Question 27

(a) M1 correct substitution: GPE = 4 x 10 x 1.8 oe
(a) A1 72 J cao
(a) Answer: 72 J
(b) B1 the kinetic energy store increases as it falls, and this energy is transferred from the gravitational potential energy store, which decreases as it falls oe
(b) Answer: The kinetic energy store increases as the shot falls, transferred from its gravitational potential energy store, which decreases.
(c) B1 some energy is dissipated to the surroundings, mainly due to air resistance acting on the shot as it falls/moves through the air oe
(c) Answer: Some energy is dissipated to the surroundings, mainly due to air resistance acting on the shot as it moves through the air.

Question 28

(a) B1 add iodine solution; positive result: colour changes from orange-brown to blue-black oe
(a) Answer: Add iodine solution; a positive result is a colour change from orange-brown to blue-black.
(b) B1 add Benedict's solution and heat in a water bath; positive result: the solution changes from blue to a brick-red/orange precipitate oe
(b) Answer: Add Benedict's solution and heat in a water bath; a positive result is a colour change from blue to brick-red/orange.
(c) B1 add biuret solution (or sodium hydroxide solution followed by copper sulfate solution); positive result: the solution turns from blue to purple/lilac oe
(c) Answer: Add biuret solution; a positive result is a colour change from blue to purple/lilac.

Question 29

(a) B1 independent variable: height of the hole above the base of the can; dependent variable: horizontal distance travelled by the water jet
(a) Answer: Independent variable: height of the hole above the base. Dependent variable: horizontal distance travelled by the water jet.
(b) B1 as the height of the hole above the base increases, the horizontal distance travelled by the jet decreases oe
(b) Answer: As the height of the hole above the base increases, the distance travelled by the water jet decreases.
(c) B1 the depth of water above a hole near the base is greater than above a hole near the top, and pressure increases with depth (due to the weight of water pushing down from above), so holes lower down experience greater pressure, forcing water out faster and further oe
(c) Answer: Holes lower down have a greater depth of water above them, and pressure increases with depth, so they experience greater pressure, forcing water out faster and further.
(d) B1 if the water level were allowed to fall, the depth of water above each hole (and so the pressure and distance travelled) would keep decreasing during the measurement, making it an unfair/inconsistent comparison between the four holes oe
(d) Answer: If the water level fell, the depth of water above each hole would keep decreasing during the measurement, making the comparison between holes unfair and inconsistent.

Question 30

(a) B1 the variety and number of rose bushes in each garden oe
(a) B1 any other valid control, e.g. the amount of sunlight/position of each garden, the starting number of aphids and ladybirds, the time of year spraying began oe
(a) Answer: The variety and number of rose bushes in each garden, and the amount of sunlight/position of each garden (or the starting aphid and ladybird numbers).
(b) B1 in the sprayed garden (A), the number of aphids fell sharply each month; in the unsprayed garden (B), the number of aphids rose steadily each month oe
(b) Answer: In the sprayed garden, aphid numbers fell sharply each month; in the unsprayed garden, aphid numbers rose steadily each month.
(c) B1 ladybirds feed on aphids, so as the pesticide greatly reduced the aphid population (their food source), there was less food available for the ladybirds, causing their population to fall too oe
(c) Answer: Ladybirds feed on aphids, so as the pesticide reduced the aphid population, there was less food available for the ladybirds, causing their population to fall too.
(d) B1 any valid reason, e.g. it reduces the food supply and therefore the population of a beneficial predator (ladybirds) that would otherwise help control aphids naturally elsewhere too, or the spray might also harm other useful insects, disrupting the wider food web oe
(d) Answer: For example, it reduces the population of a beneficial predator (ladybirds) that would otherwise help control aphids naturally, or the spray might also harm other useful insects, disrupting the wider food web.
(e) B1 repeat the comparison using several sprayed gardens and several unsprayed gardens, rather than just one of each, since a single garden of each type might not be typical/representative oe
(e) Answer: Repeat the comparison using several sprayed and several unsprayed gardens, rather than just one of each.

Science: Full Practice Paper 14 - Worksheets, Questions and Revision

CE.S-T14 Science: Full Practice Paper 14

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Question 10

Question 11

Question 12

Question 13

Question 14

Question 15

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 23

Question 24

Question 25

Question 26

Question 27

Question 28

Question 29

Question 30