Explanation: An endoscope works on the principle of total internal reflection of light. It uses optical fibers to transmit light into the body and carry the reflected image back to the observer. This allows physicians to view internal organs without surgery.

Explanation: The pair Faraday : Diffusion of gases is incorrect. The law of diffusion of gases was given by Thomas Graham, not Michael Faraday. Faraday is known for his work on electromagnetism and electrolysis. The other pairs are correctly matched.

Explanation: Vitamin K plays a crucial role in the blood clotting process. It helps the liver synthesize prothrombin and other clotting factors required to stop bleeding when injuries occur. Deficiency of Vitamin K can lead to excessive bleeding and delayed clot formation. Green leafy vegetables, broccoli, spinach, and intestinal bacteria are major natural sources of this vitamin.

Explanation: Nuclear fission is the process in which the nucleus of a heavy atom, such as Uranium-235 or Plutonium-239, splits into two or more lighter nuclei when bombarded by a slow-moving neutron. This reaction releases a large amount of energy, along with additional neutrons that can trigger further fission reactions—leading to a chain reaction. This principle is used in nuclear reactors for power generation and in atomic bombs for explosive energy release.

Explanation: Minamata disease was caused by severe mercury poisoning in the coastal city of Minamata, Japan. It resulted from the discharge of methyl mercury compounds into Minamata Bay by a chemical factory (Chisso Corporation) during the 1950s and 1960s. The toxic mercury accumulated in fish and shellfish, which were later consumed by local residents. Symptoms included numbness, muscle weakness, loss of vision, hearing and speech, paralysis, and in severe cases, death. This incident is one of the world’s worst cases of industrial pollution.

Explanation: Ecology is a branch of biology that deals with the relationships of living organisms with one another and with their physical surroundings. It examines how organisms adapt to their environment, how energy flows through ecosystems, and how matter cycles within the biosphere. The term “Ecology” was first coined by Ernst Haeckel in 1866.

Explanation: Dakshin Gangotri is India’s first scientific research station established in Antarctica in 1983–84. It was set up by the Indian Antarctic Programme under the National Centre for Polar and Ocean Research (NCPOR). Located about 2,500 km from the South Pole, it served as a base for scientific studies related to glaciology, meteorology, and environmental sciences. Though it is now buried under ice and functions as a supply base, it marked India’s permanent presence in Antarctica. Later stations include Maitri (1989) and Bharati (2012).