HSA 2007 Biology Item 47

A student’s hypothesis is that increased exercise causes increased heart rate. Heart rate is determined by taking the pulse, which is measured in beats per minute (BPM).

Which of the following data would support this student’s hypothesis?

1. When sitting, her pulse was 70 BPM; when standing, her pulse was 50 BPM.
2. When running, her pulse was 100 BPM; when sitting, her pulse was 60 BPM.
3. When sitting, her pulse was 90 BPM; when walking, her pulse was 90 BPM.
4. When running, her pulse was 65 BPM; when standing, her pulse was 70 BPM.