11.) What was the average heart rate after exercise for trial 3? * A. 148 b/m
B. 146 b/m
C. 140 b/m
D. 144 b/m
#12.) Explain the general relationship between exercise and heart rates in humans. *

A. as exercise levels increase, heart rate decreases
B. as exercise levels increase, heart rate increases
C. as exercise levels increase, heart rate remains the same
#13.) All of the following are important functions of blood in the human body except: *

A. supplying oxygen to cells/tissues
B. making the body immune by circulating white blood cells
C. sending signals to the brain in response to internal/external stimuli
D. transporting wastes away from cells
#14.) Where does the exchange of food, oxygen, and wastes occur? *

A. arteries
B. capillaries
C. veins
D. lymph vessels
Base your answer to question fifteen on the diagram below and your knowledge of science. The diagram represents a human organ system. The arrows show the directions of blood flow. Letters A and B represent locations in the system.

#15.) State one reason why blood at location B contains more oxygen than blood located at location A. *