Explanation: A parity bit is added to binary data in a computer system for error detection. It helps identify whether data has been altered during transmission or storage. The parity bit makes the total number of 1s either even (even parity) or odd (odd parity), allowing simple error checking.

Explanation: Sound waves with frequencies below 20 Hz are called infrasonic waves. These waves are inaudible to the human ear but can be produced by natural phenomena such as earthquakes, volcanic eruptions, and ocean waves.

Explanation: Saliva, secreted by the salivary glands, begins the process of carbohydrate digestion in the mouth. It contains the enzyme salivary amylase (also known as ptyalin), which catalyzes the breakdown of starch (polysaccharide) into maltose (disaccharide). This is the first step in digestion, and it occurs while food is chewed and mixed with saliva before being swallowed.

Chemical Reaction:

Starch → (Salivary amylase) → Maltose

Thus, saliva plays an essential role in the digestion of carbohydrates, making the food slightly sweet when chewed for a longer time.

Explanation: Asbestos is a group of silicate minerals once used in insulation and construction materials. Inhalation of asbestos fibers causes severe lung disorders such as asbestosis and emphysema, leading to breathing difficulty, chest pain, and even lung cancer (mesothelioma). The fibers lodge in lung tissue and trigger inflammation and fibrosis over time.

Dynamite was invented by Alfred Nobel in 1867. He was a Swedish chemist, engineer, and industrialist who discovered that nitroglycerin could be stabilized by mixing it with an absorbent material like diatomaceous earth, making it safer to handle and transport. This invention revolutionized the mining and construction industries. In his later years, Alfred Nobel established the Nobel Prizes using the wealth he accumulated from his inventions.

Other options (for context)

• J. B. Dunlop: Invented the pneumatic rubber tyre.
• James Simons: A mathematician and hedge fund manager, not an inventor.
• Peter Hargreaves: Not related to any major scientific invention; possibly confused with James Hargreaves, who invented the Spinning Jenny.

Explanation: The heart is enclosed in a double-layered protective membrane called the pericardium. The outer fibrous layer protects the heart and anchors it within the chest cavity, while the inner serous layer secretes pericardial fluid that reduces friction during heartbeats. This fluid-filled sac ensures smooth and cushioned movement of the heart as it contracts and relaxes continuously.

Explanation: Sound waves in air are longitudinal waves, meaning the particles of the medium vibrate back and forth in the same direction as the wave travels. These waves require a material medium (like air, water, or solids) for propagation and cannot travel through a vacuum.

Explanation: A fan provides a feeling of comfort during hot weather because it increases the rate of evaporation of sweat from our skin. As the perspiration evaporates rapidly due to moving air, it absorbs heat from the body, producing a cooling effect and making us feel more comfortable.