Question 1

Study the diagram of the cross-section of a flower. A, B and C are three parts of the flower. Which of the following statements are correct?
A: Part C becomes a fruit after fertilisation.
B: Pollen grains are released from part B for pollination.
C: Pollen tube grows from part A to reach the egg for fertilisation.

Accepted Answer

A. A and B only. C is the ovary, which develops into a fruit after fertilisation (statement A true). B is the stamen/anther, which releases pollen grains for pollination (statement B true). The pollen tube grows from a pollen grain on the stigma, not from part A, so statement C is false. Hence A and B only.

Question 2

The diagram shows an unborn baby in the mother's womb. Which of the following statements is true about the unborn baby?

Accepted Answer

C. It depends on his mother for nutrients when it is in the womb.. An unborn baby cannot feed itself and obtains nutrients (and oxygen) from the mother through the umbilical cord and placenta. It gets genetic information from both parents, develops for about 9 months, and carries out life processes (e.g. growth) while still in the womb.

Question 3

The diagrams below show the parts of a human male and female reproductive system. Which one of the following statements is correct?

Accepted Answer

B. The fertilised egg develops in part Z.. In the female system, Z is the uterus (womb) where the fertilised egg implants and develops. A is the testis (produces sperm, not eggs), X is the ovary (stores/releases eggs, not A), and sperms leave the male system through the penis, not part B. Hence statement B is correct.

Question 4

The diagram below shows the developmental stages of a plant. (seed → D → seedling → A → plant with flowers → B → plant with fruits → C → seed). At which points (A, B, C and D) do the processes of seed dispersal, germination and fertilisation take place?

Accepted Answer

D. Seed Dispersal C, Germination D, Fertilisation B. Germination is the growth of a seed into a seedling = arrow D (seed → seedling). Fertilisation occurs in the flower, leading to fruit formation = arrow B (plant with flowers → plant with fruits). Seed dispersal occurs from the fruit back to the seed stage = arrow C (plant with fruits → seed). Hence C, D, B.

Question 5

Study the following set-ups on the germination of seeds. Tom wanted to find out if warmth is needed for seeds to germinate. Which of the following pair of set-ups should he use to ensure a fair test?

Accepted Answer

B. B and C. To test whether warmth is needed, only temperature should differ; all else (water) must be the same. Set-up B (damp cotton wool in a warm cupboard) and set-up C (damp cotton wool in a cold refrigerator) both have damp cotton wool and differ only in temperature, making a fair test.

Question 6

The diagram below shows four identical containers P, Q, R and S. Each container was filled with water at different temperature. The containers were covered with a plastic lid and left on the kitchen table. After 15 minutes, the following observations were seen (water droplets). Arrange the containers of water in ascending order, according to the temperature of water.

Accepted Answer

B. R, S, P, Q. Warmer water evaporates faster, so more water vapour condenses as droplets under the lid. Q has the most droplets (hottest), R has none (coldest), while S and P have an intermediate amount. Ascending order of temperature is therefore R, S, P, Q.

Question 7

The diagram below shows the water cycle. A and B are processes while C and D represent the states of water. (rainfall → sea → Process A → C → Process B → D → rainfall). Which one of the following correctly identifies A, B, C and D?

Accepted Answer

D. A evaporation, B condensation, C gas, D liquid. Water from the sea (liquid) is heated and turns to water vapour through Process A = evaporation, so C is a gas. The water vapour then cools and turns into water droplets/clouds through Process B = condensation, so D is a liquid, which falls as rainfall.

Question 8

Joshua conducted an experiment as shown below. The ball and the ring were heated. Both objects were made of the same material. The ball was able to pass through the ring at room temperature. However, after heating the ball for a while, it was unable to pass through the ring. Which of the following explains this observation?

Accepted Answer

B. The ball expanded, The ring remained the same. When the ball was heated it gained heat and expanded, becoming larger so it could no longer pass through the ring. Only the ball was heated in this part, so the ring stayed the same size.

Question 9

Sally tied an inflated balloon to a brick and placed it completely in a basin of hot water as shown below. What would happen to the water level, mass and size of the inflated balloon after 5 minutes?

Accepted Answer

A. water level increase, mass of inflated balloon no change, size of inflated balloon increase. The hot water heats the air inside the balloon, so the air expands and the balloon increases in size. The balloon is sealed, so no air enters or leaves and its mass stays the same. As the balloon expands it displaces more water, so the water level rises (increases).

Question 10

Su Fen placed an empty bottle with two holes at points R and S into a basin of water as shown below. After a while, she noticed that the bottle started to sink. What could be a possible reason for this?

Accepted Answer

D. Air escaped through R while water entered through S.. For the bottle to sink, the air inside must be replaced by water so the bottle becomes heavier. Water enters through the lower hole S while air is pushed out (escapes) through the upper hole R, allowing the bottle to fill and sink.

Question 11

The diagram below shows how energy can be converted from one form to another. (Electrical Energy → A → Kinetic Energy; Electrical Energy → B → Heat Energy; Kinetic Energy → C → Heat Energy). Which set of activities best represents the conversion of energy as shown above?

Accepted Answer

D. A: Using an electric fan, B: Using an electric toaster, C: Rubbing two sticks together. A is electrical→kinetic energy = using an electric fan. B is electrical→heat energy = using an electric toaster. C is kinetic→heat energy = rubbing two sticks together (friction). Hence option D.

Question 12

Mary placed a marble in a glass tube. She observed that when she released the marble it rolled to the other end of the tube before rolling back downwards. At which position, P, Q, R or S, will the marble reach before it rolls back downwards?

Accepted Answer

C. R. As the marble rolls up the other side, its kinetic energy converts back to gravitational potential energy. Because some energy is lost to friction, it cannot reach the same height as its starting point. It therefore stops at R, just below the top point S, before rolling back.

Question 13

John bounced a plastic ball from J above the ground. The ball bounced to a lower height each time it hit the ground as shown below until it finally came to a stop at N. Which one of the following statements is correct?

Accepted Answer

C. Potential energy is decreasing from L to M.. Each successive bounce reaches a lower peak as energy is lost, so the maximum gravitational potential energy decreases from peak to peak (L to M). At J the ball is momentarily at rest (highest point), so kinetic energy is lowest there; gravitational force (weight) stays constant everywhere; and there is no reason KE equals PE at K.

Question 14

The diagram shows an electric kettle of water. It is placed under a paper cup with cut-out vanes. Which one of the following shows the energy conversion when the paper cup began to spin?

Accepted Answer

A. electrical energy → heat energy → kinetic energy. The electric kettle converts electrical energy to heat energy to boil the water. The rising hot air/steam (heat energy) then turns the cut-out vanes of the paper cup, converting heat energy to kinetic energy. Hence electrical → heat → kinetic.

Question 15

Susan had four iron balls A, B, C and D of different masses. She tied each of them to a metal pole as shown below. When the strings were released, each ball fell and created a dent in the sand. Which of the following statements is definitely correct?

Accepted Answer

B. Ball B would create a smaller dent than ball C.. Balls B and C both have the same mass (20 kg), so the only difference is height. Ball C is hung higher than ball B, giving it more gravitational potential energy and a faster fall, so it makes a bigger dent. Therefore ball B definitely makes a smaller dent than ball C. The other comparisons involve different masses and heights, so their outcomes are not definite.

Question 16

Some pupils released a ball along a ramp as shown in the diagram below. It rolled down the slope, passing through points K, L, M and moved along the carpeted floor. It finally stopped at point N. Next, the pupils placed the ball at points K, L and M and repeated the experiment respectively. The pupils made the following statements.
Don: The ball only has kinetic energy at points K and L.
Raju: The ball has the greatest amount of gravitational potential energy at point K.
Sam: The ball would have rolled further if the experiment had been done on a tiled floor.
Kim: The ball would have rolled further if the height of the support is increased.
Who had made a correct statement?

Accepted Answer

C. Raju, Sam and Kim only.. Raju is correct: among K, L and M, K is highest so it has the greatest gravitational potential energy. Sam is correct: a smoother tiled floor has less friction, so the ball rolls further. Kim is correct: a higher support gives more potential energy, hence more kinetic energy and a longer roll. Don is wrong because at K and L the elevated ball has BOTH kinetic and potential energy, not only kinetic.

Question 17

Why do we want to find other sources of energy to produce electricity?
A: Energy for coal, oil or natural gas are fast depleting.
B: Energy for coal, oil or natural gas are less efficient.
C: Energy for coal, oil or natural gas causes pollution.
D: Energy for coal, oil or natural gas produces less energy.

Accepted Answer

B. A and C only. Fossil fuels (coal, oil, natural gas) are non-renewable and fast depleting (A), and burning them causes pollution (C). They are not inherently less efficient nor do they produce less energy, so B and D are wrong. Hence A and C only.

Question 18

The diagram below shows the layers of cells in the cross-section of a leaf. John observed if there are chloroplasts in the cells A to D and recorded in the diagram as shown below (A: Has no chloroplast; B: Has lots of chloroplasts; C: Has some chloroplasts; D: Has no chloroplast). In which of the layers of cells A, B, C or D, will energy conversion take place?

Accepted Answer

C. B and C only, light energy → potential energy. Photosynthesis (energy conversion) occurs only in cells containing chloroplasts, which are cells B (lots) and C (some). During photosynthesis, light energy is converted to potential (chemical) energy stored in food. Cells A and D have no chloroplasts, so no conversion occurs there.

Question 19

Some pupils carried out an experiment to find out whether the amount of potential energy affects the horizontal distance the ball moves after reaching point B. Which of the following variables must they keep the same in order to have a fair test?
A: Height of ramp
B: Length of ramp
C: Position where the ball is released on the ramp
D: Horizontal distance moved by the ball

Accepted Answer

A. B and C only. The amount of potential energy is the variable being changed (by changing the ramp height), so height of ramp (A) must change. The length of ramp (B) and the position where the ball is released (C) must be kept the same for fairness. The horizontal distance (D) is the measured result, not a controlled variable. Hence keep B and C only the same.

Question 20

Kevin rode on a skateboard down a slope as shown in the diagram below. Which one of the following graphs correctly shows how the potential energy and kinetic energy changes as Kevin skates from A to B? (Key: Potential Energy = solid line, Kinetic Energy = dashed line)

Accepted Answer

B. Graph 2: potential energy (solid) decreases from A to B; kinetic energy (dashed) increases from A to B. As Kevin moves from A (top) to B (bottom), his height decreases so gravitational potential energy decreases, while his speed increases so kinetic energy increases. The correct graph shows the solid (PE) line falling and the dashed (KE) line rising from A to B.

Question 21

The diagram below shows a hydroelectric power station. (A: reservoir, B: moving water, C: turbine, D: generator). Which of the following matches the correct energy conversion in the hydroelectric power station?

Accepted Answer

C. kinetic energy → electrical energy: D; potential energy → kinetic energy: B. Water stored high in the reservoir has potential energy; as it falls and becomes moving water (B) this potential energy is converted to kinetic energy. The moving water spins the turbine, which drives the generator (D), where kinetic energy is converted to electrical energy. Hence kinetic→electrical = D and potential→kinetic = B.

Question 22

Force is a push or a pull. Which one of the following actions involves a push only?

Accepted Answer

A. Closing the cap of a pen.. Closing (pressing) the cap of a pen requires only a pushing force. Peeling an orange is a pull, while cutting with scissors and sweeping with a broom involve both pushing and pulling forces.

Question 23

Ben is having difficulty pushing a heavy box across a room in the direction represented by the arrow. Which of the following way(s) will help Ben push the box with less force?
A: Add rollers to the bottom of the box
B: Apply some oil on the soles of Ben's shoes
C: Ask a friend to push the box harder in the opposite direction

Accepted Answer

A. A only. Adding rollers reduces friction between the box and the floor, so less force is needed to push it (A helps). Oiling his shoe soles reduces grip and makes Ben slip, so it does not help. Pushing harder in the opposite direction increases the opposing force, making it harder. Hence A only.

Question 24

The graph below shows how the length of two springs X and Y are affected by the mass hung on each of them. Which of the following statement(s) about the graph is/are true?
A: The original length of spring X is longer than the original length of spring Y.
B: For the same amount of mass hung on each spring, spring X extends more than spring Y.
C: The greater the mass hung on the spring, the greater the extension of spring for both spring X and spring Y.

Accepted Answer

B. A and C only. At zero mass, the X line starts at a higher length than the Y line, so spring X's original length is longer (A true). Both lines rise as mass increases, so greater mass gives greater extension for both springs (C true). The two lines are parallel (same slope), so for the same mass the extensions are equal — X does not extend more (B false). Hence A and C only.

Question 25

Identical wooden blocks are pulled up using a conveyor belt on a ramp. The two blocks G and H are at different positions as shown below. Which of the following statements is not correct?

Accepted Answer

A. Block G needs more force to pull up than block H.. The blocks are identical and on the same ramp, so they have the same gravitational force, the same frictional force, and require the same force to be pulled up — regardless of their position on the ramp. The statement that block G needs MORE force than block H is therefore not correct.

Question 26

Jane taped a straw to a toy car. She attached an inflated balloon at one end of the straw as shown below. When she released the balloon, air rushed out of the balloon, exerting a force. However, the car did not move forward along the level floor. Which of the following explains Jane's observation? The toy car could not move because the force of air rushing out of the balloon was smaller than ____.
A: the weight of the straw and the toy car
B: the friction between the toy car and the floor
C: the weight of the balloon and the straw

Accepted Answer

B. B only. On a level floor the car moves horizontally, so the opposing force is the friction between the toy car and the floor. Because the force of the escaping air was smaller than this friction, the car could not overcome friction and did not move. The weights act vertically (downward) and do not oppose forward motion.

Question 27

Aaron carried out an experiment using a spring and four objects, P, Q, R and S. When each of the objects was hung on the spring, the length of the extension of the spring was measured. The table below shows the extension of the spring when the following object(s) is/are hung on it (P: 20; P and Q: 50; P, Q and R: 60; P, Q, R and S: 80). Based on the results shown in the above table, which one of the following objects exerts the least force on the spring?

Accepted Answer

C. R. Each object's individual extension shows the force it exerts: P = 20 cm; Q = 50 − 20 = 30 cm; R = 60 − 50 = 10 cm; S = 80 − 60 = 20 cm. The smallest extension (10 cm) is caused by R, so R exerts the least force on the spring.

Question 28

John set up an experiment as shown below. The rod was horizontal when magnet X was hung on it as shown in diagram 1. Object Y was then placed below magnet X as shown in diagram 2. Why did the spring stretch less as shown in diagram 2?

Accepted Answer

A. Object Y repelled magnet X.. In diagram 2 the magnet end of the rod is pushed up, reducing the pull that stretches the spring, so the spring stretches less. This upward push on magnet X means object Y exerted a repelling (pushing) force on the magnet — like poles repel.

Question 29

Roy wanted to find out if the surface area of a wooden block will affect friction. Using the set-up above, he changed the following variables to have 4 set-ups, A, B, C and D (A: surface area 30 cm², smooth, distance 30 cm; B: 15 cm², rough, 15 cm; C: 15 cm², rough, 30 cm; D: 10 cm², smooth, 30 cm). Which two set-ups above should Roy use to ensure a fair test?

Accepted Answer

C. A and D. To test whether surface area affects friction, only the surface area should differ while surface texture and distance pulled are kept the same. Set-up A (30 cm², smooth, 30 cm) and set-up D (10 cm², smooth, 30 cm) have the same texture (smooth) and the same distance (30 cm) but different surface areas, making a fair test.

P6 Science CA1 2016 — Rosyth

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P6 Science CA1 2016 — Rosyth

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