P5 Science SA1 2021 — Raffles Girls

Sam set up an experiment to find out if the speed of wind affects the distance moved by fruit X as shown below. The speed of wind of the fan can be adjusted from the slowest to the fastest by turning the knob from 1 to 5. Sam recorded the results in the table below. Knob of the fan | Distance moved by fruit X (cm) 1 | 50 2 | 103 3 | 147 4 | 188 5 | 210 (a) The following are the variables listed by Sam. Identify the correct independent variable, dependent variable and constant variables in Sam's experiment by putting a tick (✓) in the correct boxes in the table below. [2] Variables: Speed of wind; Distance moved by fruit X; Location of experiment; Time taken for fruit X to reach the ground; Height at which the fruit X was released. (b) Based on his results above, state how the wind speed affected the distance moved by fruit X. [1] (c) Explain why fruit X needs to be dispersed far away from the parent plant. [1] (d) Name the physical characteristic of fruit X which helps in its dispersal. [1]

David has two identical pieces of paper, A and B, as shown below. He placed one drop of liquid X and Liquid Y on papers A and B respectively as shown in the diagram below. After three minutes, he made the following observations as shown below. (a) Based on David's observation above, which liquid, X or Y, disappeared first? [1] Liquid ____ (b) Explain your answer in (a). [2] David carried out another experiment to find out the melting and boiling points of liquids X and Y. He recorded the results in the table below. Liquids | Melting Point (°C) | Boiling Point (°C) [ ] | -114 | 78.5 [ ] | -95 | 102 (c) Based on David's observation of liquids X and Y, complete the result table above by writing X and Y in the correct box. [1] (d) Give a reason for your answer in (c). [1]

The diagram below shows two cells, A and B, observed under a microscope. Next, cells A and B were placed on two identical petri dishes filled with the same amount of liquid X. The diagram below shows the change in cells A and B observed under the microscope half an hour later. (a) Based on the diagrams above, what could be observed of cells A and B after half an hour? [1] (b) Cells A and B were left in the same petri dish in liquid X for a few more hours. One of the cells burst. Identify the cell and explain why it burst. [2] The diagram below shows cells C viewed under a microscope. (refer to powerpoint slide shown on the screen) (c) (i) Name the group of organism that has cell C. [1] (ii) Which part of the organism identified in (c)(i) can cells C be found? Explain your answer clearly. [1]