Topic 1 - AS Biology Homework Activity
Presenting Data
Bob wanted to investigate the effect of exercise on his heart rate. He measured his pulse at rest and then again after completing 1 minute of moderate exercise. He then increased the duration of exercise by 1 minute each time up to a maximum of 5 minutes and he measured his pulse after each time. He also repeated the whole investigation a further 2 times.
His pulse measurements were as follows:
At rest it was 70, 74 and 72 beats per minute.
After 1 minute of exercise it was 90, 96 and 102
After 2 minutes it was 113, 140 and 120
After 3 minutes it was 130, 136 and 143
After 4 minutes it was 145, 135 and 149
After 5 minutes it was 157, 144 and 156
Produce a table to display the data in an appropriate way. Remember the ‘rules’ of drawing a table. Plot the results in a graph.
Calculating Percentage Change
Sara took some samples of soil from a woodland ecosystem. Each sample was placed in a paper box that had previously been weighed. These boxes of fresh soil were placed in an oven set at 70oC so that all the water could evaporate off. After a day, Sara retrieved the soil samples and re-weighed them. She then calculated the loss in mass (equivalent to water content) for each soil. Her results are shown in the table
Soil Sample SOIL A SOIL B SOIL C
Mass of fresh soil / g 347.3 231.4 561.3
Mass after heating /g 267.3 123.8 342.9
Change in mass = mass of water in soil /g
1. Calculate the change in mass for each soil
2. Sara concluded that soil C was the wettest. Was she correct? Compare the results by calculating the percentage loss in mass of each sample. Do these results agree with Sara’s original conclusion?
How to calculate percentage change
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