Science MCQs

Lactic acid is transported via the blood to the liver, where it is converted back into glucose in a process called the Cori cycle.

Smoking damages the cilia in the trachea and destroys the walls of alveoli, leading to conditions like chronic bronchitis and emphysema.

Bronchioles are the finer subdivisions of the bronchi that terminate in the alveolar sacs where gas exchange occurs.

Deoxygenated blood enters the right atrium, goes to the right ventricle, is pumped to the lungs, returns oxygenated to the left atrium, then goes to the left ventricle to be pumped to the body.

Plasma is about 92% water, along with proteins, salts, nutrients, and wastes.

Asthma causes inflammation and constriction of the airways (bronchioles), resulting in a whistling sound (wheezing) during breathing.

Double circulation refers to the two distinct circuits: the pulmonary circuit (heart to lungs and back) and the systemic circuit (heart to body and back).

Carbon dioxide reacts with calcium hydroxide in limewater to form insoluble calcium carbonate, which makes the solution appear milky.

The biconcave disc shape increases the surface area for oxygen and carbon dioxide exchange and allows flexibility.

The body increases heart rate and constricts blood vessels to try to raise blood pressure back to normal.