Explanation

• The total surface area of the respiratory surface in humans is about 20 times the size of the body.
• The human respiratory surface is formed by millions of tiny air sacs called alveoli in the lungs.
• Alveoli provide a large surface area for the exchange of oxygen and carbon dioxide between the air and blood.

Last verified on 28-10-2026

Explanation

• Bronchitis is the inflammation of the bronchial tubes, which carry air to and from the lungs.
• It commonly causes coughing, mucus production, chest discomfort, and sometimes shortness of breath.
• Bronchitis may be acute, often caused by viruses, or chronic, commonly associated with long-term exposure to irritants such as cigarette smoke.

Last verified on 28-10-2026

Explanation

• The kidneys are the main organs responsible for removing uric acid from the blood through urine.
• Approximately two-thirds (about 70%) of uric acid is excreted by the kidneys, while much of the remainder is eliminated through the intestines.
• Uric acid is produced during the breakdown of purines, which are found in body cells and certain foods.

Last verified on 28-10-2026

Explanation

• Apoptosis is programmed cell death.
• It is a natural process in which the body removes old, damaged, or unwanted cells in a controlled manner.
• Apoptosis plays an important role in embryonic development, such as removing the cells between developing fingers and toes.
• This process helps maintain healthy tissues and prevents damaged cells from surviving unnecessarily.

Last verified on 28-10-2026

Explanation

• Condensation reaction is a chemical reaction in which two molecules join together by removing a small molecule, usually water.
• When monomers join through this process, they can form larger molecules called polymers.

Additional information:

• Hydrolysis is the reverse process, in which water is used to break a chemical bond.

Last verified on 28-10-2026