Science MCQs

The left ventricle pumps oxygenated blood to the entire body under high pressure, requiring a thicker muscle wall.

Air passes through the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and finally reaches the alveoli.

The balanced equation for aerobic respiration is Glucose + Oxygen → Carbon dioxide + Water + Energy.

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.

Red blood cells circulate in the bloodstream for about 120 days before being broken down in the liver.

Asthma is often an allergic response that causes inflammation and narrowing of the airways, making breathing difficult.

Hemopoiesis is the process of forming blood cellular components.

Veins have valves to prevent backflow; arteries do not have valves.

Coronary arteries supply oxygenated blood to the heart muscle itself.

Carbon dioxide reacts with limewater (calcium hydroxide) to form calcium carbonate, which is insoluble and turns the solution milky.