During the ventricular systole, the atrioventricular valves (P) ............... and the semilunar valves (Q) ............... .

P-close and Q-open

Reason — The atrioventricular valves close to prevent the backflow of blood into the atria, and the semilunar valves open to allow blood to be pumped into the pulmonary artery and aorta.