Question 1

The flowchart below shows the characteristics of four living things, A, B, C and D. Which of the following living things is/are definitely a plant(s)?

Accepted Answer

C. C and D only. The first branch 'Does it make its own food? Yes' leads to C and D, so both C and D are producers that make their own food, which are plants. C reproduces from seeds and D reproduces from spores (e.g. ferns) — both are plants. A and B do not make their own food (A does not feed on decaying matter; B feeds on decaying matter), so they are not plants.

Question 2

The flowchart below shows how some animals are grouped. Animals G and H below can both be placed in Group Y. What could questions A and B be?

Accepted Answer

A. Question A: Do they have wings? / Question B: Do they produce milk for their young?. To reach Group Y, an animal answers Yes to Question A, Yes to 'reproduce by laying eggs', then No to Question B. Animal G (an ant/insect) and Animal H (a bird) both have wings (Yes to A) and both lay eggs, but neither produces milk for their young (No to B), so both fall into Group Y. Options C and D fail because the bird has feathers and would be separated from the insect.

Question 3

The flowchart below shows how some animals are classified. Which of the following organisms best represent A, B, C and D respectively?

Accepted Answer

B. A: mosquito, B: mealworm beetle, C: frog, D: chicken. A: has a 4-stage life cycle AND young live in water → mosquito (larvae live in water). B: has a 4-stage life cycle but young do not live in water → mealworm beetle. C: not a 4-stage life cycle but lays eggs in water → frog. D: not a 4-stage life cycle and does not lay eggs in water → chicken.

Question 4

The diagram below shows parts of a flower that has been cut into half. Process A is needed for both plant and human reproduction. Which part(s) of the flower does Process A take place in?

Accepted Answer

B. Z only. Process A needed for both plant and human reproduction is fertilisation. In a flower, fertilisation takes place in the ovule inside the ovary, which is the part labelled Z (at the base of the flower).

Question 5

The diagram shows parts of a flower at a particular stage during reproduction. Which of the following best describes structures X and Y?

Accepted Answer

B. X: A pollen after pollination but before fertilisation / Y: An ovule after pollination but before fertilisation. X is a pollen grain that has landed on the stigma (after pollination) but has not yet fertilised the ovule (before fertilisation). Y is an ovule inside the ovary, still an ovule because fertilisation has not yet happened. Both are therefore 'after pollination but before fertilisation'.

Question 6

The diagram below shows how food and gases are transported in the human body. Which of the following correctly shows the organ found in system P, Q and R?

Accepted Answer

C. System P: Stomach, System Q: Heart, System R: Lungs. Food enters system P (digestive system — stomach) and passes to system Q. System Q receives both food and gases and transports them around the body — the circulatory system (heart). System R exchanges gases with the surrounding air and exhaled air — the respiratory system (lungs). Hence P = Stomach, Q = Heart, R = Lungs.

Question 7

Xiaoting wanted to find out what would happen to a plant if part of its stem was removed as shown in Diagram 1. After some time, she noticed a bulge at part Y of the stem as shown in Diagram 2. Based on the above experiment, which one of the following statements is true?

Accepted Answer

C. The plant will die after some time as food from the leaves cannot reach the roots.. Removing a ring of bark removes the food-carrying tubes (phloem) on the outer part of the stem. Food made in the leaves travels downwards but is blocked at the cut, accumulating above it to form the bulge. The roots below no longer receive food and eventually the plant dies. Water-carrying tubes (xylem) are deeper and undamaged, so water still reaches the leaves.

Question 8

The diagram below can be used to identify part A, B, C and D of a cell. Which of the following correctly represents part A, B, C and D?

Accepted Answer

D. A: nucleus, B: chloroplasts, C: cell membrane, D: cell wall. A is present in both cell types and controls the cell's activities → nucleus. B is not present in both (plant only) and captures sunlight for photosynthesis → chloroplast. C controls substances moving in and out of the cell → cell membrane. D is the remaining part → identified as the part not present in both, giving cell wall in this option (the only option with A, B and C all correctly matched as nucleus, chloroplasts and cell membrane).

Question 9

The diagram below shows a plant cell. Which of the following parts of the plant cell, A, B, C, D, E, are not found in an animal cell?

Accepted Answer

C. A, C and E only. Parts found only in plant cells (not in animal cells) are the cell wall, chloroplasts and the large vacuole — these correspond to A, C and E. The nucleus (D) and cytoplasm/cell membrane (B) are found in both plant and animal cells, so they are excluded.

Question 10

Which of the following are produced when plants carry out photosynthesis?

Accepted Answer

B. oxygen and sugar. During photosynthesis, plants use carbon dioxide and water in the presence of light and chlorophyll to produce sugar (glucose, the food) and oxygen. Starch is a stored form made later from the sugar, not a direct product.

Question 11

An experiment was carried out in a garden with a green plant. The graph below shows the amount of oxygen produced by the green plant during a period of 24 hours. Which of the letters, A, B, C or D, on the graph represent the amount of oxygen produced at 12.00 am and 12.00 pm on a bright day?

Accepted Answer

D. 12.00 am: C, 12.00 pm: A. At 12.00 am (midnight) there is no light, so no photosynthesis occurs and the amount of oxygen produced is at its lowest — the minimum point C. At 12.00 pm (noon) on a bright day, light is strongest and photosynthesis is fastest, so oxygen production is highest — point A.

Question 12

Group X and Group Y shown below represent two different groups of organisms. Group X: lizards, snakes, scorpion, cactus. Group Y: ants, millipede, wood lice, fallen dead leaves. The table shows the characteristics of the environment found in four different habitats. In which of the habitats, A, B, C or D, would the organisms in Group X and Group Y most likely be found?

Accepted Answer

C. Group X: C, Group Y: B. Group X (lizards, snakes, scorpion, cactus) are desert organisms suited to habitat C: very high temperature in the day and very low at night, water found only as puddles, and plentiful light in the day. Group Y (ants, millipede, wood lice, dead leaves) live in a moist, shaded forest floor suited to habitat B: moderate temperature, damp soil and very little light most of the time.

Question 13

The food chain shown below represents a food relationship in a particular pond community. N is a water plant. A large population of Q is accidentally introduced into the pond. Q does not have any predators in the pond. What is likely to happen immediately if Q feeds on M only? A: The population of N will decrease. B: The population of M will decrease. C: The population of P will decrease. D: The population of Q will decrease.

Accepted Answer

B. B and C only. The food chain is N → M → P. Q feeds on M, so M's population decreases (B true). With less M available, P (which also eats M) has less food and decreases (C true). N increases because fewer M are left to eat it, so A is false. Q has abundant food and no predators, so Q increases, making D false. Hence B and C only.

Question 14

The diagram below shows part of a pond and the organisms living in it. Which one of the following shows correctly the number of different types of producers, consumers, populations and communities in the pond?

Accepted Answer

B. Producers: 3, Consumers: 2, Populations: 5, Communities: 1. There are 3 types of producers (floating plants, tall reed/cattail and submerged water plants) and 2 types of consumers (the fish). The total number of populations equals the number of different species: 3 producers + 2 consumers = 5 populations. All organisms living together in the one pond form a single community, so there is 1 community.

Question 15

The diagram below shows two animals, P and Q. Animal P stings and feeds on small organisms like ants and spiders. Animal Q looks like animal P, feeds on nectar but does not sting. Which one of the following describes the advantage for animal Q to resemble animal P?

Accepted Answer

D. Predator of animal Q would avoid preying on it, mistaking it for animal P.. Animal P can sting and is avoided by predators. Because animal Q looks like animal P, predators mistake Q for the stinging P and avoid preying on it. This resemblance protects the harmless Q from being eaten, which is the survival advantage.

Question 16

The diagram below shows two plants, X and Y, which have special adaptations to allow them to survive in their environment. Based on the diagram shown, which of the following statements about plant X and Y are correct? A: Both plants have creeping stems. B: Both plants need support to grow upwards. C: Both plants are trying to obtain more sunlight. D: Plant X has stronger stem than Plant Y.

Accepted Answer

B. B and C only. Both plants are climbers with weak stems that wind around a pole/support to grow upwards (B correct), and they climb upwards to reach more sunlight (C correct). Their stems creep upwards on a support rather than creeping along the ground, so A is wrong. Both have weak stems needing support, so X does not have a stronger stem than Y (D wrong).

Question 17

John conducted an experiment to find out changes in temperature of water. Step 1: Place a beaker of ice, 10 g in mass, at room temperature of 29°C to melt completely. Record temperature. Step 2: Then heat the same beaker of water over a burner till it reaches boiling point. Record temperature. Step 3: Continue boiling water for 5 minutes. Record temperature. Step 4: Remove beaker from burner to allow water to cool to room temperature of 29°C. Record temperature. He recorded his data in a graph after each step. Which one of the following graphs most likely represents the changes in temperature of water over the duration of his experiment?

Accepted Answer

A. Graph 1. The temperature should rise from near 0°C (melted ice water) up to 100°C, stay constant at 100°C while boiling for 5 minutes (a flat plateau), and then fall and level off at the room temperature of 29°C (not lower). Graph 1 shows this rise, a plateau at 100°C, then a gradual cooling curve that levels off around room temperature.

Question 18

The diagrams below show two types of glasses with different designs. Design A has a double layer of glass as compared to Design B which has a single layer of glass. Ahmad poured water at 10°C into both glasses and left them in the same room. Which one of the following graphs correctly shows how the temperature of water changes with time in each type of glass?

Accepted Answer

B. Graph 2 (B rises above A). The room is warmer than the 10°C water, so heat flows into the water and its temperature rises in both glasses. Design A's double layer of glass is a better insulator, so heat gain is slower and its water warms up more slowly (lower curve). Design B, with a single layer, gains heat faster and warms up more quickly (higher curve). Graph 2 shows B rising above A, both starting at 10°C.

Question 19

Substance A and Substance B are in two different states of water. The diagram below shows the properties of Substances A and B. Substance A: Has no definite shape, has definite volume. Substance B: Has no definite shape, has no definite volume. What process takes place as Substance A changes into Substance B?

Accepted Answer

A. Boiling. Substance A has no definite shape but a definite volume — a liquid. Substance B has no definite shape and no definite volume — a gas. A liquid changing into a gas is boiling (evaporation), so the process is boiling.

Question 20

An electromagnet can be made using two batteries, wires and an iron nail as shown in the diagram below. In a closed circuit, the iron nail becomes an electromagnet. How can the strength of the electromagnet be increased? A: Use a longer nail. B: Increase the length of wire used. C: Increase the number of batteries in series. D: Increase the number of turns of wire around the nail.

Accepted Answer

B. C and D only. An electromagnet is made stronger by increasing the current or the number of coils. Adding more batteries in series increases the current (C) and increasing the number of turns of wire around the nail increases the magnetic effect (D). Using a longer nail (A) or a longer wire (B) does not increase the strength — a longer wire actually adds resistance.

Question 21

The diagram below shows four bulbs connected together in a circuit. Which of the switches, S1, S2, S3, S4, should be closed for all the bulbs to light up?

Accepted Answer

C. S1, S2 and S4 only. For every bulb to light, a complete path must run through all four bulbs while avoiding any switch position that would short-circuit (bypass) a bulb. Closing S1, S2 and S4 completes the circuit so current flows through all four bulbs; leaving S3 open prevents a branch that would otherwise bypass part of the circuit.

Question 22

The diagram below shows three circuits with different arrangements of identical batteries and bulbs. The bulbs in all three circuits light up. Arrange the bulbs, Q, R and S, in the order of brightness, starting with the bulb which was the brightest.

Accepted Answer

A. Q, R, S. Brightness depends on the voltage across each bulb. Bulb Q's circuit has two batteries driving a single bulb, giving it the highest voltage and the greatest brightness. Bulb R's circuit shares two batteries among more bulbs (or a parallel arrangement) giving it moderate brightness, while bulb S's circuit has only one battery, giving the lowest voltage and least brightness. Order brightest to dimmest: Q, R, S.

Question 23

The container below was filled with tap water of room temperature at 28°C. A flask of coloured water was then placed into the container. The water level in the glass tube was marked out with a thread. Ice cubes were added in the container and a change in temperature of water was recorded. Which one of the following correctly describes the level of water in the tube after ice cubes were added and the reason for the observation?

Accepted Answer

A. Water Level: Falls / Reason: Water in the flask loses heat and contracts. Adding ice cools the water in the container to below the flask's temperature. The coloured water in the flask loses heat to the cooler surrounding water and contracts, so the coloured water level in the glass tube falls below the thread mark.

Question 24

The diagram below shows a metal spoon left in a pot of hot soup over a stove by Mrs Leong. After 20 minutes, Mrs Leong used her hands to remove the metal spoon from the pot. The metal spoon burned her hand. Which of the following explains why the metal spoon burned her hand? A: Mrs Leong's hand lost heat to the spoon. B: Mrs Leong's hand gained heat from the spoon. C: The heat on Mrs Leong's hand transferred to the spoon. D: The spoon gained heat from the hot soup then lost heat to Mrs Leong's hand.

Accepted Answer

C. B and D only. The metal spoon, a good conductor, gained heat from the hot soup and became hot. When held, the hotter spoon transferred (lost) heat to Mrs Leong's cooler hand, so her hand gained heat and was burned. Thus B (hand gained heat from spoon) and D (spoon gained heat from soup then lost heat to hand) are correct.

Question 25

Martin carried out an experiment in a dark room with the set-up as shown below. He arranged 4 sheets of different materials A, B, C and D in a straight line. When the torch was switched on, he observed that a bright patch of light in the shape of a crescent was seen on sheet C only. Which of the following statements is/are definitely true about the sheets used above? A: Sheet A is opaque. B: Sheet B is transparent. C: Sheet C is transparent. D: Sheet D is translucent.

Accepted Answer

B. A and B only. The crescent shape of light means Sheet A blocked all the light except through the crescent hole, so Sheet A is opaque (A true). The bright, clearly-shaped crescent reached Sheet C, so light passed clearly through Sheet B — Sheet B is transparent (B true). The light patch stopped ON Sheet C and no light reached Sheet D, so Sheet C is opaque, not transparent (statement C false). Nothing can be concluded about Sheet D. Hence A and B only.

Question 26

A river runs through a forest as shown in the diagram below. Which of the following will most likely decrease the amount of pollutants in the river at point X? A: Plant more trees nearer to point X. B: Minimise use of pesticide in the farm. C: Stop dumping of sewage from the houses into the river.

Accepted Answer

A. A only. Point X lies upstream of the farms and houses (the river flows from the forest down towards the farms and houses). Only sources upstream of X can affect the water at X. The farms and houses are downstream, so their pesticide and sewage do not reach X. Planting more trees near X reduces pollutants (roots hold soil and absorb pollutants), so only A helps.

Question 27

Dora had a spring with an original length of 15 cm. She wanted to find out the relationship between the extension of the spring and different weights. She hung different weights on the spring, one at a time, and measured its extension. She recorded and plotted the results on the graph below. Based on the graph, what would be the length of the spring when a 200 g weight was hung on it?

Accepted Answer

D. 33 cm. From the graph, a 200 g weight gives an extension of about 18 cm. The length of the spring = original length + extension = 15 cm + 18 cm = 33 cm.

Question 28

A ladder is placed leaning against a wall as shown below. Which one of the following shows correctly the direction of frictional force acting on the ladder when it is sliding down from the wall?

Accepted Answer

D. Top arrow up, bottom arrow pointing left (toward wall). Friction always opposes the direction of motion at each contact point. As the ladder slides down, the top end moves downwards against the wall, so friction at the wall acts upwards. The bottom end slides outwards away from the wall, so friction at the ground acts inwards (towards the wall). Hence the top friction arrow points up and the bottom friction arrow points towards the wall.

Question 29

Susan used a fridge magnet to attach a piece of paper on the door of the refrigerator as shown in the diagram below. When she attached a thin piece of paper, the magnet was able to hold it onto the refrigerator's door. When a thicker piece of paper was used, both the magnet and the paper fell onto the floor. Based on the above information, which of the following statements are not correct? A: Paper is a material that prevents magnetic force from passing through. B: The surface of the refrigerator's door is made of a magnetic material. C: Force of gravity is only acting on the thicker paper but not on the thin paper.

Accepted Answer

B. A and C only. The question asks which statements are NOT correct. A is not correct: the magnet still held the thin paper, so magnetic force does pass through paper — thickness only increases the distance and weakens the force. C is not correct: gravity acts on both papers, not only the thick one. B is correct (the door is a magnetic material, since the magnet sticks to it), so it is excluded. The incorrect statements are A and C.

Question 30

The diagram below shows layers of cells in a leaf. In which of the layers of cells, A, B, C or D, will conversion of energy from one form to another take place?

Accepted Answer

C. Layers B and C only: light energy → chemical potential energy. Photosynthesis converts light energy into chemical potential energy (stored in food). This happens in cells containing chloroplasts — the palisade layer (B) and the spongy mesophyll layer (C). The upper epidermis (A) and lower epidermis (D) have few or no chloroplasts, so the conversion takes place in layers B and C only.

P6 Science SA2 2014 — Henry Park

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P6 Science SA2 2014 — Henry Park

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