P6 Science CA1 2025 — Pei Chun

P and Q are similar beakers containing the same volume of digestive juices. Equal amounts of potato are placed in the beakers. In which beaker would the potato take a longer time to be digested and what was the reason? (1) P — The potato has a smaller volume. (2) P — The potato has a smaller exposed surface area. (3) Q — The potato has a smaller exposed surface area. (4) Q — The potato has a larger volume.

Which of the following help(s) to hold the plant upright? (1) B only (2) C only (3) A and B only (4) A and C only

Nazrul removed an outer ring of the stem from a plant as shown below. As a result, the food-carrying tubes between positions X and Y were removed while the water-carrying tubes remained in the stem. He left the plant in an open area and watered it daily for one week. Which of the following diagrams shows the appearance of the stem after one week? [Figure: Four diagrams (1)-(4) showing different stem-bulge patterns around the ringed gap: (1) stem same width above and below; (2) bulge above only; (3) stem same width above with bulge below; (4) bulge above the ring and same width below.]

The table shows the breathing rates of Ben and Ken during an exercise. Which statement is correct? (1) Ben's breathing rate was higher than Ken's breathing rate. (2) Ben breathed in less oxygen per breath as compared to Ken. (3) Ben and Ken have the same breathing rate when they are resting. (4) Ben's breathing rate increased more than Ken's breathing rate during the exercise.

The diagram below shows the movement of blood to and from a human heart. The same amount of blood was taken from blood vessels A, B, C and D. The graph shows the amount of carbon dioxide present in the four blood samples. [Figure: Bar graph of carbon dioxide amounts for samples M, N, O, P — M is high, N is very low, O is highest, P is medium-low.] Which blood vessel was blood sample P most likely taken from?

May set up an experiment in a dark room as shown. She placed a lamp at a distance of 10 cm from the glass jar. After one hour, she observed that 6 cm³ of gas was collected in the syringe. She repeated the experiment by placing the lamp at different distances from the glass jar. Which of the following shows the most likely result of the experiment? (1) 20 cm — more than 6 (2) 20 cm — equal to 6 (3) 5 cm — more than 6 (4) 5 cm — equal to 6

Which of the following must a plant have to carry out photosynthesis? A stomata B chloroplasts C food-carrying tubes D water-carrying tubes (1) A and C only (2) B and D only (3) A, B and C only (4) A, B and D only

The diagram shows a mobile phone. What are the properties of the material used to make the screen? [Table with properties Flexible / Waterproof / Allows light to pass through; options (1) ✓✓✗ (2) ✓✗✓ (3) ✗✓✗ (4) ✗✓✓.]

John made a game using the objects shown below. The lower end of the bar was used for catching toy fish. Bar P could catch fish A and B only. Bar Q could catch fish B and C only. Which of the following about bars P and Q is correct? (1) Both bars P and Q are magnets. (2) Both bars P and Q are magnetic objects. (3) Bar P is a magnet and bar Q is a magnetic object. (4) Bar P is a magnetic object and bar Q is a magnet.

Kelly conducted an experiment using the set-up below. When the circuit was closed, the bar magnet was attracted to the electromagnet. She measured the distance d between the bar magnet and the electromagnet. She repeated the experiment with only one battery. How would distance d change and what was the reason? (1) decreased — decreased (2) decreased — increased (3) increased — decreased (4) increased — increased

Jasmine set up four circuits using identical batteries and bulbs in working condition to find out whether the arrangement of the bulbs in a circuit affects the brightness of the bulbs. Which two circuits should Jasmine use for her investigation? (1) W and Y (2) W and Z (3) X and Y (4) X and Z

Six metal pins, A, B, C, D, E and F, were fixed onto a wooden board as shown in Diagram 1. Diagram 2 shows a battery and a bulb connected to two wires X and Y. Garron connected some but not all of the pins on the wooden board in Diagram 1 with wires. He then connected X and Y across different pairs of pins in turn. He recorded his results in the table below. [Table: A-B yes, A-F yes, C-D no, D-E yes.] Which of the following correctly shows the connections made by Garron? [Figure: Four options of pin-wiring diagrams.]

Jenny threw a ball into the air. The ball flew up to V, then dropped down to W as shown below. Which of the following correctly describes the changes in the gravitational force acting on the ball and mass of the ball as it moved from V to W? (1) decreased / decreased (2) decreased / remained the same (3) remained the same / decreased (4) remained the same / remained the same

Kate hung three identical springs, P, Q and R, each attached to a block of equal mass from the ceiling. The results are as shown. Which of the following correctly shows the relationship between the elastic spring force and the extension for springs P, Q and R? [Figure: Four extension vs force graphs.]

Four identical bottles were placed on a shelf at different heights. Bottles Y and Z are completely filled with water while bottles W and X are half-filled. Which of the following statements is/are true? A Bottle Z has the most gravitational potential energy. B Bottle W has the most gravitational potential energy. C Bottle X has less gravitational potential energy than bottle Y. D Bottle X and Y have the same amount of gravitational potential energy. (1) B only (2) C only (3) A and C only (4) B and D only

Hamid performed a jump on a trampoline. The diagram below shows him at different positions, J, K and L. Hamid stood on the stretched trampoline at J before jumping up. He continued moving upwards from K to L. At L, he reached his highest point and stopped moving for a split second before falling. Which of the following correctly describes the energy at J, K and L? [Table: (1) J kinetic — K PE+KE — L PE; (2) J kinetic — K PE — L kinetic; (3) J PE — K PE+KE — L PE; (4) J PE — K kinetic — L PE]

(a) State what digestion is. [1] (b) Paul ate a bowl of food X. Food X is digested into sugar. After four hours, the doctor measured the amount of sugar in various parts of the digestive system. Based on the graph, state whether food X is digested in the stomach. Explain why. [1] (c) The amount of sugar decreased between parts N and O. Explain why. [1] (d) Undigested food enters an organ after leaving the small intestine. Name this organ. State the main function of this organ. [1]

(a) Four parts of a plant are shown. Draw arrows (→) in the diagram below to show how water is transported in a plant. [1] (b) Linda cut the lower stem of a white flower into two equal parts. She placed them into containers with different coloured water as shown. [Figure: White flower with stem split into two; one half in red-coloured water, the other half in blue-coloured water.] After a short time, she observed that some parts of the flower turned red, some turned blue, while the rest remained white. Explain her observations. [2]

Johan placed the same amount of pond water which contained tiny living things Q into two identical glass containers, X and Y. He painted container Y black. He placed both containers at the same place under bright light. He measured the amount of oxygen in each container daily. The results for container X are shown. [Figure: Graph of amount of oxygen vs days — line for container X increases steadily over time.] (a) Explain why the amount of oxygen in container X increased. [1] (b) On the graph, draw a line to show how the amount of oxygen in container Y changes. Both containers X and Y had the same amount of oxygen at the start of the experiment. [1] (c) Suggest one possible reason that could have resulted in Johan obtaining inaccurate results. [1]

May set up the apparatus as shown below. In the set-up, the drop of red ink prevents air from entering the test tube. After a while, she observed that the drop of red ink moved towards the test tube. (a) Explain how the gaseous exchange of the insects caused the drop of red ink to move towards the test tube. [2] (b) Name a gas inside the test tube that remained the same in amount throughout the experiment. [1]

Ahmad set up an experiment as shown below to compare a property of three strips, A, B and C, which are made of different materials. For each strip, he added a 500 g mass and measured the distance d moved by the end of the strip. His results are shown below. [Table: A 500 g — 4 cm; B 500 g — 0.5 cm; C 500 g — 2 cm.] (a) Based on Ahmad's experiment, which strip, A, B or C, is most suitable for making a food tray? Explain your answer. [1] (b) State two variables of the strips that should be kept the same for the experiment to be a fair test. [1] Variable 1: ___ Variable 2: ___ (c) Ahmad conducted another experiment with strips A, B and C. He added different masses for each strip until distance d of each strip is the same. Based on the results above, write down the strip with the most mass added. [1]

Devi placed two ring magnets, G and H, through a wooden rod as shown in Diagram 1. She observed that magnets G and H were 4 cm away from each other. Devi removed the magnets and placed them through the wooden rod again as shown in Diagram 2. (a) Explain why magnets G and H stayed apart as shown in Diagram 1. [1] (b) Suggest a reason why the distance between the two magnets was greater when magnet H was placed above magnet G. [1] (c) Devi pushed magnet H towards magnet G as shown below. [Figure: Hand pushing magnet H down towards magnet G; distance P between them.] She found that she needed to push harder as distance P decreases. Explain why. [1]

Hassan placed a block on a plank as shown in the diagram below. (a) He observed that block did not slide down the plank. Name the force(s) acting on the block when it was resting on the plank. [1] (b) Hassan set up an experiment as shown below. He pulled the block up the plank using a spring balance. He repeated the experiment for different values of angle x. He wanted to find out how the pulling force changes with angle x. [Figure: Spring balance pulling the block up an inclined plank at angle x.] Hassan used the same block throughout the experiment. Give a reason how using the same block helps to make the experiment a fair test. [1] (c) The table below shows the results of Hassan's experiment. [Table: Angle x (°) 0/10/20/30 — Pulling force (units) 50/125/175/200.] State the relationship between the pulling force and angle x. [1] (d) Hassan pulled the same block down the same plank using a spring balance as shown below and measured the force required to pull the block down the plank. [Figure: Spring balance pulling block down the plank at angle 20°.] (i) Based on the results of Hassan's experiment, how much would the pulling force be? Choose your answer by ticking (✓) in the correct box. [1] ☐ less than 50 units ☐ more than 50 units but less than 175 units ☐ more than 175 units (ii) Give a reason for your answer in (i). [1]

Ivy set up a circuit to play a game. She wants to remove the plastic ball from the metal ring with a pair of metal tongs. If the pair of metal tongs touches the metal ring, the bulb lights up and the player loses. (a) The diagram below shows part of the circuit. Use a pencil to complete the circuit below such that when the pair of metal tongs touches the metal ring, the bulb will light up. [2] (b) Ivy added a new bulb to the circuit and the brightness of the first bulb decreased when the circuit was closed. Describe how Ivy connected the new bulb to the circuit. [1] (c) The game cannot be played if the ring is made of plastic. Explain why. [1]