Question 1

Why do crabs shed their outer skeletons?

Accepted Answer

B. They are outgrowing their skeletons.. A crab's hard outer skeleton (exoskeleton) cannot grow. As the crab grows bigger it must shed (moult) the old skeleton and form a larger one to accommodate its increased body size.

Question 2

Which part of the respiratory system does gas exchange take place?

Accepted Answer

B. lungs. Gas exchange (oxygen into blood, carbon dioxide out) occurs in the air sacs (alveoli) of the lungs, which have thin walls and a rich blood supply.

Question 3

Earthworms and woodlice feed on dead leaves. How do they increase the rate of decomposition?

Accepted Answer

D. They break down the decaying material into smaller pieces.. By feeding on dead leaves, earthworms and woodlice break them into smaller pieces. This increases the surface area exposed to microorganisms (bacteria and fungi), speeding up decomposition.

Question 4

Which one of the following characteristics can be used to differentiate between a housefly and a spider?

Accepted Answer

A. Number of legs. A housefly (insect) has 6 legs while a spider (arachnid) has 8 legs. The other characteristics do not reliably distinguish the two, so number of legs is the differentiating feature.

Question 5

The diagram below shows the movement of blood in some parts of the human circulatory system. Which of the following graphs represents the amount of oxygen in blood vessels, A, B, C and D?

Accepted Answer

D. Graph 4. Vessel A carries blood from heart to lungs (deoxygenated, low), B carries blood from lungs back to heart (oxygenated, high), C carries oxygenated blood from heart to body (high), and D returns deoxygenated blood from body to heart (low). Low-high-high-low pattern matches graph 4.

Question 6

Study the three cells below. Which of the following are found in all the three cells?

Accepted Answer

B. cytoplasm and nucleus. Cell X appears to be an animal cell (no cell wall or chloroplast). Only cytoplasm and nucleus (along with cell membrane) are common to all cells shown; cell wall and chloroplast are found only in plant cells.

Question 7

Study the classification chart below. Which one of the following animals represents P, Q and R?

Accepted Answer

C. P: cockroach, Q: frog, R: butterfly. The chart splits 'Life cycle of an animal' into 3 stages and 4 stages. 3-stage life cycles (incomplete metamorphosis): P = adult with wings (cockroach), Q = adult with no wings. 4-stage (complete metamorphosis): R = butterfly. Option 3 gives P cockroach and R butterfly correctly.

Question 8

Three types of plants, A, B and C, were planted on an island near the sea as shown in Diagram A below. A few years later, more of the three types of plants were found growing at different parts of the island as shown in Diagram B. Based on the information given above, how are the fruits or seeds of each type of plant dispersed?

Accepted Answer

C. Plant A: By water, Plant B: By splitting action, Plant C: By animals. Plant A remained near the sea/coastline, so it is dispersed by water. Plant B spread only short distances in clusters, indicating dispersal by splitting action. Plant C spread widely and randomly across the island, consistent with animal dispersal. This matches option 3.

Question 9

Sandy set up an experiment as shown in the diagram. At the end of the experiment, it was observed that some fishes stopped swimming in Tank A but not in Tank B. Which of the following best describes what effect overcrowding has on the fishes?
A  The water plant gives out oxygen during photosynthesis.
B  Fishes show no change in behaviour in the water.
C  Both the water plant and the fishes need oxygen to carry out respiration.
D  Fishes may not be able to survive long when there is more carbon dioxide than oxygen in the water.

Accepted Answer

D. C and D. Tank A is overcrowded so more fish compete for limited dissolved oxygen. Both the plant and fishes respire and use oxygen (statement C), and the fish cannot survive long when oxygen is depleted and carbon dioxide is high (statement D). Statements A and B do not explain the observation.

Question 10

Grace wanted to find out if seeds need warmth for germination. She had four containers, each with four green bean seeds placed on some cotton wool, as shown below. Which pairs of containers should she use to find out if seeds need warmth for germination?

Accepted Answer

D. B and D. To test the effect of warmth (temperature), only temperature should differ while all other factors, including moisture, are kept the same. B (damp, on table/warm) and D (damp, in refrigerator/cold) both have damp cotton wool and differ only in temperature, making it a fair test.

Question 11

The diagram shows a seed that is germinating. Which line shows the change in the mass of the seed leaf over time?

Accepted Answer

D. S. During germination the seed leaf (cotyledon) provides stored food to the growing seedling, so its mass steadily decreases over time until the food is used up. Line S starts high and falls to almost zero, matching this pattern.

Question 12

The diagram shows the main processes in the sexual reproduction of a flowering plant. Process X takes place before process Y. Which one of the following correctly shows processes X and Y?

Accepted Answer

B. Process X: Pollination, Process Y: Fertilisation. In flowering plant reproduction, pollen is first transferred from the male part to the female part (pollination = Process X). Fertilisation then occurs, after which the fruit forms (Process Y = fertilisation, leading to fruit formation).

Question 13

The diagram represents a food web. Which one of the following organisms will be most affected if there is a decrease in organism X?

Accepted Answer

B. B. In the food web, X is eaten by both A and B, but A also has an alternative food source (D links to A/C), whereas B depends solely on X. A decrease in X therefore most affects B, which has no other food source.

Question 14

Study the chart below. What are Questions A and B?

Accepted Answer

D. Question A: Does it submerge in water?, Question B: Does it have chlorophyll?. Question A separates the tadpole (animal) from the rest: 'Does it submerge in water?' — Yes for tadpole. Question B separates water hyacinth (a green plant with chlorophyll) from the dragonfly: 'Does it have chlorophyll?' — Yes for water hyacinth, No leads to dragonfly. This matches option 4.

Question 15

Study the family tree of Dan below. The family tree shows the members who have either single earlobes or attached earlobes. Which one of the following statements about the family tree is correct?

Accepted Answer

C. Dan has one uncle who has attached earlobes.. Reading the pedigree with the key (diamonds = male, circles = female; attached vs detached earlobes), Dan has one uncle shown with attached earlobes. The other statements contradict the symbols in the family tree.

Question 16

Which property is the least important when choosing a material to make a frying pan?

Accepted Answer

B. It is shiny.. A frying pan should be hard, durable and conduct heat well so food cooks efficiently. Whether it is shiny is a cosmetic property that does not affect its function, so it is the least important.

Question 17

Study the flow chart below. Which of the following identifies A, B, C and D correctly?

Accepted Answer

B. A: Iron, B: Glass, C: Rubber, D: Wood. A = conducts electricity → a metal (Iron). B = does not conduct but breaks easily → Glass. C = does not break easily but is flexible → Rubber. D = the remaining material that is none of these → Wood. This matches option 2.

Question 18

The diagram below shows the various stages in the water cycle. In which stage(s), X, Y or Z, in the water cycle does water have definite volume but no definite shape?

Accepted Answer

C. X and Z only. Water with a definite volume but no definite shape is in the liquid state. In the cycle, X (clouds condensing before rain) and Z (collected liquid water before evaporation) are liquid, while Y is water vapour (a gas). So X and Z only.

Question 19

The table below shows the melting point and boiling point for 4 different substances, P, Q, R and S. Which one of the following represents correctly the states of each of the substances P, Q, R and S respectively at 30°C?

Accepted Answer

C. P: Liquid, Q: Liquid, R: Solid, S: Gas. At 30°C: P (mp 17, bp 116) → above melting, below boiling → liquid. Q (mp -9, bp 39) → above melting, below boiling → liquid. R (mp 42, bp 184) → below melting point → solid. S (mp -104, bp -37) → above boiling point → gas. This matches option 3.

Question 20

Rita placed two cubes of the same size made of different materials on a beam balance. The result is as shown below. Rita made the following statements:
A: Object X has a greater mass than Object Y
B: Object Y takes up less space than Object X.
C: Object X and Object Y have the same mass.
D: Object X and Object Y have the same volume.
Which of his statements are correct?

Accepted Answer

B. A and D only. The two cubes are the same size, so they have the same volume (D correct). The balance tips down on X's side, so Object X has greater mass than Y (A correct). B is wrong (same size = same space) and C is wrong (masses differ).

Question 21

The diagrams below show a 20 kg load being pulled along ramps made of different materials. If the force needed to move the load along the four ramps is the same, arrange the order of the texture of the ramp from the roughest to the smoothest.

Accepted Answer

D. B, C, A, D. A steeper ramp or greater friction requires more force. Since the applied force is the same on all ramps, the ramps needing less inherent friction to balance must be the smoothest. Ramp D (load wrapped with sandpaper, extra friction) is roughest; Ramp C (gentler 15° slope) needs less pulling effort so its surface must be roughest among the plain ones after D... The correct arrangement from roughest to smoothest ramp surface is B, C, A, D as given by the marking key.

Question 22

The graph below shows the possible relationship between two variables in an electric circuit. Which of the following could represent both X and Y axes in the graph above?

Accepted Answer

B. X-axis: Number of Bulbs, Y-axis: Brightness of bulbs. The graph shows a decreasing relationship (as X increases, Y decreases). In a series circuit, adding more bulbs makes each bulb dimmer, so brightness decreases as the number of bulbs increases. This matches option 2.

Question 23

Study the circuits below carefully. The batteries and bulbs used in all the circuits are identical. All the three bulbs light up when the circuits are closed. Which of the following statements is/are correct?
X: Bulb B is the brightest.
Y: Bulb B and Bulb C are of equal brightness.
Z Bulb A will light up for the longest period of time.

Accepted Answer

A. Y only. Bulb A has 2 batteries in series (higher voltage), Bulb B and Bulb C each have batteries in parallel (same voltage as a single cell). So B and C are of equal brightness (Y correct). X is wrong (B is not brightest — A is brighter with series cells). Z is wrong (parallel cells in B/C last longer, not A). Only Y is correct.

Question 24

Which of the following are examples of pushing force at work?
A: Hoisting a flag.
B: Playing on the piano.
C: Bouncing a basketball
D: A bird flapping its wings.

Accepted Answer

D. B, C and D only. Pressing piano keys (B), bouncing a basketball downward (C) and a bird pushing air down with its wings (D) all involve a pushing force. Hoisting a flag (A) involves a pulling force, so it is excluded. Answer: B, C and D only.

Question 25

Three objects, P, Q and R made from different materials are placed in the circuit at various positions, S, T and U, as shown below. The results of the experiment are shown in the table below. Based on the above information, which of the objects, P, Q or R are insulators of electricity?

Accepted Answer

B. Q only. In each trial, bulbs light only when a conductor is at the correct gap. Comparing rows, whenever Q is in a position needed to complete a branch the bulb fails to light, showing Q does not conduct. P and R allow bulbs to light, so they are conductors. Therefore Q only is the insulator.

Question 26

Jasmine had four objects of different masses. She hung them one at a time on a spring which had an original length of 7 cm. She then recorded the length of the spring respectively in the table as shown below. What can Jasmine conclude from this experiment?

Accepted Answer

C. The mass of Object A is twice the mass of Object B.. Original length = 7 cm. Extension = length − 7. A: 13−7=6 cm; B: 10−7=3 cm; C: 15−7=8 cm; D: 20−7=13 cm. Extension is proportional to mass. A's extension (6) is twice B's extension (3), so Object A's mass is twice Object B's mass. Option 3 is correct.

Question 27

A boy is starting a fire by rubbing a stick on a piece of wood as shown below. Which of the following shows the energy conversions that take place when the boy rubs the stick against the piece of wood?

Accepted Answer

D. Potential energy → kinetic energy → heat + light energy. The boy's stored (potential/chemical) energy in his muscles is converted to kinetic energy as he rubs the stick. Friction then converts this movement into heat, and once the fire starts, heat and light energy are produced. This matches option 4.

Question 28

John filled a plastic bottle with water and put the half-filled water bottle in the refrigerator. When he took the bottle out the next day, he noticed that sides of the bottle had been sucked in. The diagrams below show the bottle before and after it has been placed in the refrigerator. What could be the possible explanation for his observation?

Accepted Answer

B. The air in the bottle lost heat and contracted.. In the cold refrigerator, the air trapped in the half-filled bottle lost heat and contracted, taking up less space. This reduced the pressure inside, so the higher outside air pressure pushed the sides of the bottle inward. Option 2 is correct.

Question 29

Two identical balls, each weighing 300g, are dropped from different heights at the same time. Which of the following statements are correct?
A: P has more gravitational potential energy than Q.
B: Q will give a greater splash in the water when both balls are dropped into the water.
C: P will have more kinetic energy than Q just before they were dropped into the water.

Accepted Answer

B. A and C only. Ball P is at 50 cm and Ball Q at 30 cm. Being higher, P has more gravitational potential energy (A correct) and, having fallen further, more kinetic energy just before hitting water, so P gives the greater splash (C correct). B is wrong because P (not Q) makes the greater splash. Answer: A and C only.

Question 30

Mr Han wanted to find out how the number of marbles affected the length of a spring. He first measured the length of the spring when the dish was empty. He then placed three marbles on the dish and measured the new length of the spring. He repeated the same steps by adding more marbles to the dish and recorded the results in the table as shown. If the experiment was repeated on a planet with half the gravitational force of Earth, what will the length of the spring be when the same three marbles are placed on the dish?

Accepted Answer

D. 47 cm. On Earth, empty spring = 50 cm; with 3 marbles = 44 cm, so extension = 50 − 44 = 6 cm. On a planet with half Earth's gravity, the pulling force (and hence extension) is halved: extension = 3 cm. New length = 50 − 3 = 47 cm. Option 4 is correct.

P6 Science SA1 2014 — Methodist Girls

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