Explanation: Coriander (Coriandrum sativum) is a herb belonging to the family Apiaceae. The leaves are used as a fresh herb (commonly known as cilantro), and the dried fruits (often referred to as coriander seeds) are used as a spice. The fruits contain essential oils like linalool and borneol, which give coriander its characteristic aroma and flavor.

Uses:

• Leaves — used in cooking for flavoring and garnishing dishes.
• Dried fruits (seeds) — used as a spice, in curry powders, and for medicinal purposes (digestive aid).

Explanation: Aerosols (such as those used in spray cans, refrigerants, and air conditioners) often contain chlorofluorocarbons (CFCs) and other halogen compounds. These chemicals rise to the stratosphere, where ultraviolet (UV) radiation breaks them down, releasing chlorine atoms. Each chlorine atom can destroy thousands of ozone (O₃) molecules, leading to ozone layer depletion. The thinning of the ozone layer allows more harmful UV rays to reach Earth, increasing the risk of skin cancer, eye damage, and affecting ecosystems.

Explanation: Carbon monoxide (CO) is a colorless, odorless, and highly poisonous gas. When inhaled, it competes with oxygen for binding sites on the haemoglobin molecule in red blood cells. CO has approximately 200–250 times greater affinity for haemoglobin than oxygen. As a result, it forms a stable compound called carboxyhaemoglobin (HbCO).

This compound prevents haemoglobin from carrying oxygen to body tissues, leading to oxygen deprivation (hypoxia). Prolonged exposure to CO can cause headache, dizziness, nausea, unconsciousness, and even death due to suffocation.

Chemical Reaction:

Hb + CO → HbCO (Carboxyhaemoglobin)

Explanation: Insulin is a hormone secreted by the beta (β) cells of the Islets of Langerhans in the pancreas. Its main function is to regulate the blood glucose level by promoting the uptake of glucose into cells and converting excess glucose into glycogen in the liver and muscles. A deficiency or lack of insulin causes diabetes mellitus, leading to high blood sugar levels. The pancreas also secretes glucagon, which performs the opposite function by increasing blood glucose levels.

Explanation: Proteins are complex organic compounds composed of smaller units called amino acids. Each amino acid contains an amino group (–NH₂), which contributes nitrogen to the molecular structure. This makes nitrogen an essential element in all proteins. Carbohydrates and fats lack nitrogen, while only some vitamins contain it.

Explanation: Uranium-235 (U-235) is the isotope used for the production of atomic energy because it is fissionable. When bombarded with neutrons, U-235 undergoes nuclear fission, releasing a large amount of energy along with additional neutrons, which sustain the chain reaction in nuclear reactors and atomic bombs.

Explanation: The S.I. unit of electric current is the Ampere (A). It is defined as the rate of flow of electric charge through a conductor. One ampere equals one coulomb of charge passing through a point in one second.

Explanation: The full form of USB is Universal Serial Bus. It is a standard interface used to connect devices such as keyboards, mice, flash drives, and printers to a computer. USB allows data transfer and power supply between connected devices.

Metrology is the science of measurement. It deals with the establishment of units of measurement, their standards, and the development of new measuring methods and instruments. Metrology ensures accuracy and consistency in measurements across scientific research, engineering, manufacturing, and trade. It is broadly classified into three types — scientific metrology, industrial metrology, and legal metrology.

Other options (for context)

• Weather: The study of weather and atmosphere is called Meteorology, not Metrology.
• Distance: Measuring distance is just one aspect of metrology, not its entire scope.
• None of these: Incorrect — metrology specifically refers to measurement science.

Explanation: A concave mirror can produce an image that is larger than the object when the object is placed between the mirror’s pole and its focal point. This property makes concave mirrors useful in applications like shaving mirrors and makeup mirrors, where magnified images are needed.