How To Graph Biology Lab Experiments

Graphs can be a valuable and important aid to the comprehension of complex sets of data. We are exposed to many graphs in daily life. However, if you need to draw a graph for a biology lab experiment there are rules you will need to follow or your data will be rejected or your grade will suffer.

Step 1

Label your graph "Figure 1" at the top of the graph paper. This can also be abbreviated "Fig. 1". Subsequent graphs will be labeled "Figure 2", and "Figure 3", etc. When referring to your graph in the text, refer to it as "Figure 1".

Step 2

Select a point for the X,Y- intercept, or origin, of your graph. This will likely be in the bottom left hand area of the graph. Allow room for labeling the variables and numbering the units of measure to the left of the Y-axis (vertical) and below the X-axis (horizontal). Use the X-axis as the "constant" and the Y-axis for the "variable". You must label both your axes with what you are measuring and in parentheses write the units used to measure.

Step 3

Number your units of measure along the Y-axis. If the constant on the X-axis is quantitative (by number or value), use numbers; and use words if it is qualitative (by type or quality). Because you included the units in parentheses following what was being measured, all that needs to be along the axis is numbers.

Step 4

Place a dot where the vertical line passing through the control value intersects with the horizontal line passing through the measured variable for each measurement recorded in the biology lab experiment.

Step 5

Give your graph a title. Most likely it will be whatever your variable is compared to whatever your constant is. Examples would be Growth (variable) over Time (constant) or Precipitation (variable) by Month (constant) or Biomass (variable) vs. Average Temperature (Constant). The title is in title case (Capitalizing important words). The title will either be at the top of the graph just below "Figure 1" or just below the label of the X-axis.

Step 6

Include a line of best fit