Science MCQs

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration.

The left ventricle pumps blood to the entire body, which requires greater force and higher pressure than pumping to the nearby lungs.

Valves between the heart chambers (e.g. tricuspid, bicuspid) ensure blood flows in one direction only.

The correct order is: Nostrils -> Nasal Cavity -> Pharynx -> Larynx -> Trachea -> Bronchi -> Bronchioles -> Alveoli.

Chemoreceptors are most sensitive to the buildup of carbon dioxide in the blood, which triggers an increased breathing rate.

Regular exercise strengthens the heart muscle, allowing it to pump more blood with each beat and lowering resting heart rate.

Plasma is the liquid part of blood that contains fibrinogen (a clotting factor). Serum is plasma with the clotting factors removed.

Mucus in the nose, trachea, and bronchi traps dust, pollen, and microorganisms, preventing them from entering the lungs.

A sphygmomanometer is the device used to measure blood pressure.

The balloon sheath stretched across the bottom of the bottle represents the diaphragm, which moves down to simulate inhalation.