Question 1

The following flowchart shows the characteristics of four different organisms. Which of the following correctly identify organisms A, B, C and D?

Accepted Answer

B. A: Bracket fungus, B: Centipede, C: Bird's nest fern, D: Mimosa plant. A does not make food and breaks down dead matter = decomposer (bracket fungus). B does not make food and does not decompose = animal (centipede). C makes food and reproduces by spores = bird's nest fern. D makes food, does not use spores, and has seeds dispersed by animals = mimosa plant.

Question 2

Study the diagrams of the two life cycles as shown below (a mosquito life cycle with stages A and B, and a grasshopper life cycle with stage C). Which of the following describe the characteristics at stages A, B and C, respectively?

Accepted Answer

B. A: moults, B: lives in water, C: does not have wings. In the mosquito life cycle the immature stages develop in water and moult as they grow. In the grasshopper's incomplete metamorphosis, stage C is the nymph, which does not yet have functional wings.

Question 3

Three cells are as shown below (Cell K, Cell L and Cell M). Which one of the following shows the correct classification and common parts found in all cells?

Accepted Answer

B. Plant cell: K, L; Animal cell: M; Common parts: cytoplasm, nucleus, cell membrane. Cells K and L have a regular shape with a cell wall, so they are plant cells (K also shows chloroplasts). Cell M is irregular with no cell wall, so it is an animal cell. The parts common to all cells are the cell membrane, cytoplasm and nucleus.

Question 4

The diagram below shows parts of the human digestive system, P, Q, R and S. Which one of the following shows the correct classification of the parts to the functions?

Accepted Answer

A. Removes water from undigested food: S; Adds digestive juices to break down food: P, Q, R; Passes digested food to the bloodstream: R. P is the mouth/oesophagus, Q is the stomach, R is the small intestine and S is the large intestine. The large intestine (S) removes water from undigested food; the mouth, stomach and small intestine (P, Q, R) add digestive juices; the small intestine (R) passes digested food into the bloodstream.

Question 5

Nilam carried out an experiment to investigate the conditions necessary for seed germination. Set-ups A to E show the different conditions in which the seeds were placed. In which of the set-ups would Nilam observe the seeds germinating after two days?

Accepted Answer

B. B and D only. Seeds need water, air and suitable warmth to germinate (light is not needed). Set-up B (seeds with water and air at 30°C) and set-up D (cupboard at 30°C with water and air) provide all three conditions. A lacks sufficient water contact, C has boiled water sealed by oil (no air), and E in the refrigerator (3°C) is too cold.

Question 6

The diagram below shows the direction of the blood flow in some parts of the body. The same amount of blood was taken from A, B, C and D. Which chart shows the correct comparison of the amount of oxygen in the blood samples?

Accepted Answer

B. Bar chart comparing B and A, with B higher than A. A (heart to lungs) carries deoxygenated blood (low oxygen), B (lungs to heart) carries oxygenated blood (high oxygen). Therefore B has more oxygen than A, which the chart in option B correctly shows.

Question 7

The diagrams below show the fruits of three species of plants, X (with a feathery structure), Y (with stiff hairs and seeds) and Z (with seeds). The dispersal patterns of these three plants, A, B and C, are shown below. Which species of plants best match the dispersal patterns respectively?

Accepted Answer

A. Species X: B, Species Y: A, Species Z: C. Species X has a feathery structure for wind dispersal, so its seedlings spread widely in the direction of the wind (Pattern B). Species Y has stiff hairs/hooks for animal dispersal, spreading seedlings far and in many directions (Pattern A). Species Z's seeds drop near the parent plant (Pattern C).

Question 8

Suresh prepared the set-up below and left it under the sun for 8 hours. Then he tested the leaf for the presence of starch using iodine solution. What would Suresh observe about the colour of iodine when he added it to parts P, Q and R of the leaf after 8 hours?

Accepted Answer

C. P: dark blue, Q: brown, R: brown. Part P receives light and carbon dioxide, so it photosynthesises and makes starch, turning iodine dark blue. Part Q is covered by black tape (no light) and part R is enclosed in the plastic bag with pellets that absorb carbon dioxide (no CO2); both cannot make starch, so iodine stays brown.

Question 9

The diagram below shows a plant that has been cut at part A and B. At part A, a cut was made to remove the food-carrying tubes. At part B, a cut was made to remove both tubes carrying water and food. Which of the following is/are likely to happen after three days? A: The leaves growing below part A will wither. B: The leaves growing above part B will wither. C: All the leaves growing on the plant will wither.

Accepted Answer

A. B only. At part B both the water-carrying (xylem) and food-carrying (phloem) tubes are removed, so leaves above part B receive no water and will wither. At part A only the food tubes are removed; water still rises through the xylem, so those leaves do not wither within three days. Hence only statement B is correct.

Question 10

The diagram below shows the organisms in a garden. Which of the following statements are true? A: All the consumers can fly. B: There are three populations of consumers. C: There is an animal population to help disperse the seeds. D: The plants depend on three animal populations for pollination.

Accepted Answer

B. B and C only. The caterpillar is the young stage of the butterfly, so the consumer populations are birds, butterflies and the bee — three populations (B true). The birds can help disperse seeds, so there is an animal population for seed dispersal (C true). Statement A is false because the caterpillar cannot fly, and D is false because fewer than three animal populations pollinate the plants.

Question 11

Study the food web of a pond community as shown below. Which of the following statements about the food web are not true? A: There are six consumers. B: The water plant is a source of food for three plant eaters. C: The dragonfly nymph and the tilapia are both prey and predators. D: All the energy in the tadpole is transferred to the dragonfly nymph.

Accepted Answer

B. A and D only. Statement D is not true because energy is lost between trophic levels, so not all the energy in the tadpole is transferred to the dragonfly nymph. Per the marking key, statement A is also taken as not true. Statements B and C are true.

Question 12

The food web below illustrates the relationship among several different organisms in a rice field. A population of Animal Z was then introduced into the rice field. The graph shows what happened to the populations of two organisms, A and B, after Animal Z preyed on an animal in the food web (population A increases, population B decreases over time). Which of the following correctly shows the prey of Animal Z and resulted in the change of population sizes for two of the organisms, A and B?

Accepted Answer

B. Prey of Animal Z: toad, Organism A: snail, Organism B: rat. If Animal Z preys on the toad, the toad population falls. With fewer toads eating snails, the snail population rises (Organism A increases). Fewer toads also means the snake has less food, so it eats more rats, causing the rat population to fall (Organism B decreases).

Question 13

Mr Singh conducted an experiment to find out which species of ladybird, G or H, could better control the population of spider mites in his farm. He put two ladybirds G into set-up 1 and two ladybirds H into set-up 2. He also put five spider mites into each set-up and left them undisturbed for 3 hours. Which one of the following will help Mr Singh to draw a conclusion at the end of his experiment?

Accepted Answer

D. Control set-up: water, 1 plant, 5 spider mites; Data for collection: The number of spider mites left in each set-up.. To compare how well each ladybird controls spider mites, the data collected must be the number of spider mites left in each set-up. A fair control set-up with no ladybirds (water, 1 plant, 5 spider mites) provides a baseline showing how many mites remain when no ladybird is present.

Question 14

Abigail found a graph on the internet that shows the average global temperature over time (rising trend from 1880 to 2010). Which of the following correctly show the cause and the effect of the trend shown in the graph?

Accepted Answer

A. Cause: Burning more forests; Effect: More haze. The graph shows global temperatures rising (global warming). Per the marking key, the matched cause and effect is the burning of more forests leading to more haze.

Question 15

The table below shows the properties of four different materials (W, X, Y, Z and whether each is flexible, a good conductor of heat, strong, waterproof). Ashraf wanted to bring some cold water to school. He needed a bottle which he could squeeze into his small bag together with his books without the bottle breaking. Which one of the materials is most suitable for making Ashraf's bottle?

Accepted Answer

A. W. The bottle must be flexible (to be squeezed into the bag), strong (so it does not break) and waterproof (to hold water). Material W has all three of these properties, making it the most suitable.

Question 16

Which of the following is/are (an) example(s) of effects of a force? A: a closed door blocking noise from a television. B: a thick piece of glass blocking heat from the stove. C: a window glass stopping wind from entering the house. D: a piece of wood stopping current from passing through a circuit.

Accepted Answer

B. C and D only. A force can stop a moving object. In C the window glass stops the moving wind (moving air) and in D the wood stops the moving current; per the marking key both are taken as effects of a force. Blocking noise (A) and blocking heat (B) are not effects of a force.

Question 17

Samy poured water of different temperatures into three identical cups and put them each into three identical rooms with different room temperature. After some time, Samy observed very tiny water droplets forming on cups A and C as shown below. Which one of the following shows correctly the temperature of the water in each of the cups?

Accepted Answer

D. Cup A: 39°C, Cup B: 9°C, Cup C: 27°C. Water droplets form on the outside of a cup when the cup surface is colder than the surrounding air, causing water vapour in the air to condense. Droplets formed on cups A and C but not on B. This is the option selected by the marking key.

Question 18

Keng Siong prepared a set-up as shown below (a bar magnet hanging from a spring balance above an electromagnet made of an iron bar with coils of wire connected to a battery). He then made some changes to the value of a variable, S, in the set-up and recorded the corresponding readings on the spring balance as shown in the graph (reading increases as S increases). Based on the above results, which of the following represent variable S? A: Amount of heat applied to the bar magnet. B: Number of coils of wire around the iron rod. C: Number of batteries connected in series with the iron bar.

Accepted Answer

C. B and C only. Increasing the number of coils (B) or the number of batteries (C) makes the electromagnet stronger, increasing the downward magnetic pull on the bar magnet and so increasing the spring-balance reading. Applying heat to the bar magnet (A) weakens its magnetism, which would decrease the reading, so A is not the variable.

Question 19

The table below shows the freezing and boiling points of three different substances (S: freezing 20°C, boiling 30°C; T: freezing 3°C, boiling 22°C; U: freezing 67°C, boiling 150°C). Ali put the three substances into three identical sealed containers and left them in a room with a temperature of 30°C. The substances all started as solids. Which of the following would Ali observe after some time?

Accepted Answer

D. S: empty (gas); T: empty (gas); U: solid at bottom. At 30°C: substance S (boiling point 30°C) reaches its boiling point and becomes a gas; substance T (boiling point 22°C) is above its boiling point and becomes a gas; substance U (freezing point 67°C) is below its freezing point and remains a solid. So both S and T containers appear empty (gas) and U stays solid.

Question 20

Sally filled balloon A with 500 ml of water and another identical balloon B with 500 ml of air. She then put each balloon into two identical containers of capacity 1000 ml. Two identical metal plates were each placed on the balloons as shown below. Next, she added 1000 ml of water into each of the containers. Which one of the following statements is correct?

Accepted Answer

B. More water would overflow from container A than container B.. The water-filled balloon A cannot be compressed, so it keeps occupying 500 ml and only 500 ml of added water fits before overflowing. The air-filled balloon B is compressible; the weight of the plate and water compresses it, creating more space for water, so less water overflows. Hence more water overflows from container A.

Question 21

Jane released a ball from the top of a slope at P. The diagram below shows the path taken by the ball before it comes to rest at T. Which of the following statements about the ball is/are correct? A: It comes to rest at T when all its energy has been used up. B: It has maximum gravitational force at P and no gravitational force at S and T. C: It possesses only kinetic energy and no gravitational potential energy between S and T. D: The kinetic energy of the ball at Q is the same as its kinetic energy at R.

Accepted Answer

B. C only. Between S and T the ball is moving along the lowest (ground) level, so it has only kinetic energy and no gravitational potential energy (statement C is correct). A is wrong because energy is converted, not used up; B is wrong because gravity acts everywhere; D is wrong because the ball loses energy to friction between Q and R, so its kinetic energy is not the same at both points.

Question 22

Jackson conducted an experiment using the set-up shown (a battery, bulb M and a switch in a single loop). He measured the amount of light given off by bulb M. In his second experiment, he connected another identical bulb N and a switch to the circuit above. He measured the amount of light produced by bulb M again and found that the amount of light produced by bulb M is different. Which of the following statement(s) about the circuit in Jackson's second experiment is/are correct? A: Each bulb can be switched on or off independently. B: When one bulb is spoilt, the other bulb can still light up. C: There is only one path for current to flow through the circuit.

Accepted Answer

B. C only. Because bulb M's brightness changed when bulb N was added, the bulbs must be connected in series. In a series circuit there is only one path for current (C correct). The bulbs cannot be switched independently (A wrong) and if one bulb is spoilt the circuit breaks so the other goes off (B wrong).

Question 23

The following diagram shows the cut-outs A, B, C and D (each 10 cm tall) that Hannah prepared for a puppet show. She wants to use the puppets to create the scene shown for her audience. Which one of the following shows the correct positions of the puppets?

Accepted Answer

D. Option 4 arrangement (A and C at back, B and D in front). A shadow is larger when the cut-out is placed closer to the light source (further from the screen) and smaller when placed closer to the screen. The audience also sees a left–right reversed image. Matching the relative sizes and left–right positions of the shadows in the desired scene gives the arrangement in option 4.

Question 24

Mei Feng suspended three bars freely using two different set-ups and obtained the results shown (Set-up 1 with bars P and Q hanging level; Set-up 2 with bars P and R hanging tilted). She then arranged the three bars in a T-shape and put three compasses at three different positions (compass A to the left of bar Q, compass B above bar P, compass C to the right of bar R), with North pointing up. Which one of the following shows the direction which each compass would point to?

Accepted Answer

A. Compass A: up (North), Compass B: up (North), Compass C: up (North). Based on the suspension results the bars are not behaving as strong magnets that would deflect the compasses, so each compass simply aligns with the Earth's magnetic field and points North (up). Per the marking key, all three compasses point North.

Question 25

Fatimah left a remote control car near the bottom of a slope. Once she pressed the 'Forward' button on her remote control, the car moved forward. She then pressed the 'Stop' button but the car continued to move forward and up the slope before falling to the floor. Which one of the following correctly shows the energy conversion in the car after she had pressed the Forward button on her remote control?

Accepted Answer

C. potential energy → electrical energy → kinetic energy → potential energy → kinetic energy → sound + heat energy. The chemical (potential) energy stored in the battery is converted to electrical energy, then to kinetic energy as the car moves. Going up the slope the kinetic energy is converted to gravitational potential energy, which becomes kinetic energy again as it falls, and finally sound and heat energy when it lands.

Question 26

Mike was in an enclosed bathroom. He poured some tap water onto a pile of hot stones, which were at a temperature of 200°C. Immediately, he observed a lot of mist forming above the stones. Which one of the following correctly explains the temperature of the room after water was poured onto the stones?

Accepted Answer

C. Temperature increased — Water gained heat from the stones and became hot water vapour.. The water poured onto the very hot stones gains heat from them and evaporates into hot water vapour, which forms the mist. This heat is released into the enclosed room, so the room temperature increases.

Question 27

Chee Meng set up four electrical circuits as shown below. The batteries and bulbs are all identical and working properly. Which bulb would light up the brightest after bulb X is removed from each of the circuits?

Accepted Answer

D. D. After bulb X is removed, the brightest bulb is the one that still receives the full battery voltage with the fewest other bulbs sharing the current. In circuit D, removing X leaves bulb D in a configuration that draws the most current, so it lights up the brightest.

Question 28

Boon Tiong attached one end of a spring to the floor. The other end of the spring was attached to a bar magnet, A, on a ramp. When he placed magnet B on the top of the ramp, it slid down the ramp and stopped at the position shown (above magnet A, not touching it or the spring). Which of the following is correct about the forces acting on magnet B?

Accepted Answer

C. Elastic spring force: absent; Frictional force: present (up ramp); Gravitational force: present (vertically down); Magnetic force: present (up ramp). Magnet B is not touching the spring, so there is no elastic spring force on it. Friction acts up the ramp (opposing its tendency to slide down), gravitational force acts vertically downwards, and magnetic repulsion from magnet A acts up the ramp (pushing B away). This matches option C.

P6 Science SA2 2018 — Methodist Girls

Related Sparks

P6 Science SA2 2018 — Methodist Girls

Related papers

Related Sparks