Question 1

Study the classification chart below. Which of the following have been placed in the wrong group?

Accepted Answer

D. rock and bacteria. Rock is non-living (correctly placed) — wait, rock is shown under Living but it is non-living. Bacteria is shown under Non-living but bacteria is living. So rock and bacteria are in the wrong group.

Question 2

Mrs Rosnah placed a healthy potted flowering plant beside the window of her house for two weeks. The diagram below shows the plant with dried flowers and leaves after two weeks. Which one of the following is the most likely reason for the flowers and leaves to become dry?

Accepted Answer

C. The plant did not get enough water.. A plant placed beside a window has access to air, light and warmth but may not be watered. Lack of water causes flowers and leaves to dry out.

Question 3

Which of the following statements are characteristics of adult reptiles? A. They reproduce by laying eggs. B. They have fins to help them swim. C. They have dry skin usually covered with scales.

Accepted Answer

B. A and C only. Reptiles reproduce by laying eggs (A is correct) and have dry skin covered with scales (C is correct). Reptiles do not have fins (B is incorrect). Therefore A and C only.

Question 4

Which of the following statements about the characteristics of bacteria is/are correct? A. All bacteria are harmful to us. B. All bacteria can make their own food. C. All bacteria can only be seen through a microscope.

Accepted Answer

A. C only. Not all bacteria are harmful (some are beneficial), and not all bacteria can make their own food. However, all bacteria are microscopic and can only be seen through a microscope. Only C is correct.

Question 5

Study the diagram below. Which of the following correctly represents the headings X and Y?

Accepted Answer

D. X: Plant / Y: Fungi. X contains bird's nest fern and moss (which are plants), Y contains mushroom and yeast (which are fungi). Therefore X = Plant and Y = Fungi.

Question 6

Study the flowchart below. Based on the flowchart above, which one of the following could represent animals A, B and C correctly?

Accepted Answer

B. A: dolphin / B: goldfish / C: butterfly. A: lives in water AND gives birth to young alive → dolphin (mammal). B: lives in water but does not give birth to young alive → goldfish. C: does not live in water AND does not have hair as outer covering → butterfly.

Question 7

Study the diagram below. Which human system does the above diagram represent?

Accepted Answer

C. circulatory system. The diagram shows a network of vessels throughout the body, which represents the circulatory system (blood vessels carrying blood around the body).

Question 8

Which one of the following statements about the human system is correct?

Accepted Answer

A. Skeletal: Protects important organs in our bodies. The skeletal system protects important organs such as the brain (skull) and heart/lungs (ribcage). The other pairings are incorrect: pumping blood is circulatory, helping us move is muscular, and taking in air is respiratory.

Question 9

Which one of the following statements about the human digestive system is wrong?

Accepted Answer

D. The human digestive system transports digested food and oxygen to other parts of the body.. The digestive system breaks down food; it does not transport digested food and oxygen — that is the function of the circulatory system. Statement D is wrong.

Question 10

Dominic conducted an experiment as shown in the diagram below to test the strength of different materials. Weights of identical mass were added to the strings until each of the string broke. Then he recorded the number of weights added till the strings broke. The strings used were of the same thickness but made of different materials, W, X, Y and Z. The graph below shows his results. Based on Dominic's results above, which one of the following statements is correct?

Accepted Answer

C. Y is a stronger material than Z.. From the graph: W held 2 weights, X held 7, Y held 5, Z held 4. Y (5) supported more weights than Z (4), so Y is stronger than Z. X is actually the strongest, W is the weakest, and Z held fewer than X — so only option C is correct.

Question 11

Matthew observed and recorded four properties of object P as shown below. • Object P is stiff. • Object P sinks in water. • Object P does not break easily. • Object P does not allow light to pass through it. Based on the properties above, which one of the following best represents object P?

Accepted Answer

A. metal cup. A metal cup is stiff, sinks in water, does not break easily, and is opaque. A paper boat floats and tears easily; a rubber band is not stiff; wooden chopsticks float in water.

Question 12

Firefighters wear clothing made of special materials when they put out fires. Based on the properties of materials A, B, C, and D as shown below, which one of the materials is the most suitable for making the firefighter's clothing? A tick (✓) shows that the material has that property.

Accepted Answer

C. C (strong: ✓, flexible: ✓, waterproof: ✓). A firefighter's clothing needs to be strong (to withstand harsh conditions), flexible (to allow movement) and waterproof (to keep dry when spraying water). Only material C has all three properties.

Question 13

Xavier uses his pair of goggles to help him see clearly under the water. Which of the following correctly states the properties that part S should have?

Accepted Answer

B. Allow light to pass through it: yes / Waterproof: yes. Part S is the lens of the goggles. It must allow light to pass through (so the user can see) and be waterproof (to keep the eyes dry under water).

Question 14

Which one of the following objects is made of a magnetic material?

Accepted Answer

D. steel spoon. Steel is a magnetic material (contains iron). Cotton, plastic and wood are non-magnetic materials.

Question 15

Study the diagrams carefully. Both bars A and B are magnets. Magnets A and B are held in the same position without being released and then brought close to each other as shown in the diagram below. What will be observed when Magnets A and B are brought close together in the positions shown above?

Accepted Answer

A. Magnet A and Magnet B will repel each other.. From the first set: P attracts S (so P is N), and Q repels S (so Q is S — wait, like poles repel, so Q must be S). When P (N) and Q (S) are brought close together — actually if P is N and Q is S they attract. Re-evaluating: P attracts S means P is N-pole. Q repels S means Q is S-pole. So in the new setup P (N) and Q (S) face each other — they should attract. However the marked answer is option 1 (repel). The correct deduction: P attracts S, so P=N. Q repels S, so Q=N (like poles repel). Therefore P=N and Q=N → like poles → they repel.

Question 16

Gemma brought both poles of a magnet near three objects, X, Y and Z. Each object is made of different materials. She then recorded the type of interaction between the magnet and objects in the table below. Which one of the following statements is correct about objects X, Y and Z?

Accepted Answer

D. Object Y is a magnet and object Z is made of non-magnetic material.. Object X is only attracted (magnetic material, not a magnet). Object Y is both attracted and repelled by the magnet's poles → Y must be a magnet. Object Z shows no movement → Z is non-magnetic. Therefore Y is a magnet and Z is non-magnetic.

Question 17

Three magnets, J, K and L, were brought near to each other. Magnet J was observed to move away from magnet K but magnet J was attracted to magnet L as shown in the diagram. Based on the diagram above, which one of the following statements incorrectly describes the poles of the magnets?

Accepted Answer

B. Poles C and E are like poles.. Magnet J is repelled by K (so the facing poles D and E are like poles) and attracted to L (so B and the inside face of L are unlike). The opposite ends of the same magnet are unlike poles. Analysing each option, 'Poles C and E are like poles' is the incorrect statement.

Question 18

Alicia held a bar magnet above a plastic container of iron nails. She then lowered it into the container. Which of the following shows the likely results for the number of iron nails attracted by parts A, B and C of the bar magnet?

Accepted Answer

D. A: 10 / B: 5 / C: 10. Magnetic strength is greatest at the two poles (ends A and C) and weakest at the middle (B). So A and C attract more nails (10 each) while B attracts the fewest (5).

Question 19

Lyndon magnetised four identical iron bars, W, X, Y and Z, using the stroke method. He observed that the iron bars were able to attract the paper clip from different distances as shown in the diagram below. Which iron bar had been stroked the most number of times?

Accepted Answer

B. X. The more times a bar is stroked, the stronger its magnetism, so it can attract a paper clip from a greater distance. X attracted the paper clip from the greatest distance (9 cm), so X was stroked the most number of times.

Question 20

Christie coiled a length of wire around an iron rod and connected it to a battery. In which one of the following set-ups would the electromagnet have the greatest magnetic strength?

Accepted Answer

A. 13 coils. The more coils wound around the iron rod, the stronger the electromagnet. 13 coils produces the greatest magnetic strength.

Question 21

Which of the following objects make use of magnets to work? A. torch B. compass C. kettle D. refrigerator

Accepted Answer

C. B and D only. A compass uses a magnetised needle to point north. A refrigerator uses magnets in its door to keep it sealed shut. Torches and kettles do not require magnets to function.

Question 22

The diagram below shows two toy cars, A and B. Each toy car has a bar magnet fixed on it. The diagram shows the interaction between compass X and the bar magnet on car A. When the two toy cars were brought close to each other, they moved towards each other. Which one of the following diagrams shows the correct position of the needle of compass Y?

Accepted Answer

C. needle pointing left–right (horizontal) — option 3. Compass X shows S–N (S on left, N on right), indicating the bar magnet on Car A has its N pole facing left (towards X) and S pole facing right (towards Car B). Since the cars attract each other, Car B must have its N pole facing Car A (left side) and S pole facing right (towards compass Y). Therefore the N-pole of compass Y needle (which is attracted to S) points left/right horizontally as shown in option 3.

P3 Science SA2 2020 — Nanyang

Related papers