Two students make the following claims regarding the components of the solar system. • Student 1: The components of the solar system were formed from a spinning nebular
cloud containing dust, hydrogen, helium, and other gases that condensed under the
influence of gravity.
Student 2: The components of the solar system were likely to have been formed at the
same time as the formation of the universe the universe.

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