In an experiment that tests how different fertilizers effect the growth of
plants, what would the INDEPENDENT
variable be?
A. the growth of the plants
B. the fertilizers
C. multiple groups with the same plant and fertilizer
D. a plant without fertilizers

1. beginning with all chambers of the heart in the "relaxed" phase, describe the cardiac cycle in mammals, with systole and diastole of the atria and ventricles. for each time point in the cycle you select, state the following: • whether the atria and ventricles are contracting or relaxing • whether the av valves and semilunar valves are closed or open • whether the pressure in the atria and ventricles is high or low