Graph
Graphs are drawn to show experimental data obtained during scientific experiments.
It is important to consider the following when drawing a graph:
- The x-axis should be labelled (with the independent variable) and include appropriate units.
- The y-axis should be labelled (with the dependent variable) and include appropriate units.
- A suitable scale should be used that is even and results in the graph taking up at least half of the page.
- The plots should be accurately plotted.
- The plots should be joined with the appropriate straight line or curve.
Graphs are then used to identify trends present within the experimental data.
When forming a trend it is important to cover the entire graph.
Multiple trends in a graph should be individually described, using data as evidence.
Example
Practical B3: Investigating the effect of temperature on the action of an enzyme
As temperature increases from 0掳C to 40掳C, the time taken for starch digestion decreases.
As the temperature increases above 40掳C, the time taken for starch digestion increases.