Chapter 1, Problem 7STP

Interpretation Introduction

Interpretation:

To choose which student serves as the control from the given options.

Concept introduction:

The heart rate is the number of times the heart beats per minute. In an adult human, the average heart rate is 72 beats per minute.

Answer to Problem 7STP

Correct answer: Option (a)

Explanation of Solution

Option (a) Student 1.

Consuming soda that is caffeine mildly increases the heart rate as there is an increase in the hormone epinephrine which increases the blood pressure, eventually increasing the contractility of the heart that results in increase in the heart rate. The average heart rate in humans is 70-75 beats per minute, thus the student 1 acts as the control because he has consumed zero cans of soda that shows a stable heart rate. Therefore, this is the correct answer.

Conclusion

Option (b) Student 2 has consumed 1 can of soda that resulted inan increase of 11 beats per minute. Option (c) Student 3 has consumed 2 cans of soda that resulted in an increase of 16 beats per minute.

Option (d) Student 4 has consumed 4 cans of soda that resulted in an increase of 73 beats per minute.

Thus, option (b), (c) and (d) are incorrect as they have consumed some amount of soda that resulted in an increased heart rate.