Year 7 Science · AC9S7I04

Tables, graphs, models and mathematical relationships

Choose the representation that best organises or processes the scientific information.

  1. Which representation best compares bird counts at four habitat types? Justify.
  2. Which representation best shows water temperature every minute for 15 min? Justify.
  3. Which representation best tests whether plant height is related to light intensity across 30 plants?
  4. State four features required on a well-constructed scientific graph.
  5. Why is the independent variable usually placed on the x-axis?
  6. A graph uses 0, 10, 20, 50, 60 at equal visual spacing. Explain the problem.
  7. Explain why changing the graph scale can change visual impression but not the data.
  8. When is a dichotomous key more useful than a line graph?
  9. Give one strength and one limitation of a food-web model.
  10. Raw masses are 4.2, 4.4 and 4.3 g. Calculate the mean and state why raw values should still be kept.
  11. A spreadsheet automatically produces a pie chart for temperature versus time. Evaluate the choice.
  12. Design the best representation for a dataset containing time (min), temperature (°C) and three repeated trials. Describe the raw table and final graph.

Answers / marking guidance

1–4

1 Column/bar graph: categorical habitat groups. 2 Line graph: continuous ordered change through time. 3 Scatter plot: paired numerical variables and relationship. 4 Accept descriptive title, labelled axes, units, even scale, accurate points and legend where needed.

5–8

5 It is the explanatory/changed/ordered variable used to compare the response. 6 The scale is uneven and will distort distances; intervals must be represented proportionally. 7 Scale changes how differences look, not the numerical observations. 8 A dichotomous key is for identifying/classifying an unknown item through paired choices, not showing numerical change.

9–12

9 Strength: shows feeding/energy-transfer links among multiple organisms. Limitation: simplifies quantities, timing and many real interactions. 10 Mean = 4.3 g; keep raw values so spread, errors and processing can be checked. 11 Pie chart is unsuitable for ordered continuous change; use a line graph. 12 Table: Time (min) first, Trial 1/2/3 Temperature (°C) columns, optionally calculated mean in a separate processed column; graph time on x-axis and temperature/mean on y-axis, with trials or mean clearly identified.