Explanation: The processes that add carbon dioxide (CO₂) to the carbon cycle on Earth are:

• 1. Volcanic action: Volcanic eruptions release large amounts of CO₂ and other gases from the Earth’s interior into the atmosphere.
• 2. Respiration: All living organisms release CO₂ as a by-product of breaking down glucose during cellular respiration.
• 4. Decay of organic matter: Decomposition of dead plants and animals by microbes produces CO₂ and methane (CH₄).

Photosynthesis (option 3), on the other hand, removes CO₂ from the atmosphere as plants use it to produce glucose and release oxygen.

Ocean Thermal Energy (OTE) is produced due to the temperature difference at different levels in the ocean. The surface water is warmer because it absorbs sunlight, while the deeper layers remain cold. This temperature gradient is used to run a heat engine that generates electricity — a process known as Ocean Thermal Energy Conversion (OTEC).

• Tides: Related to gravitational pull, not temperature.
• Pressure difference: Exists but not used for energy generation.
• Waves: Used in wave energy systems, not OTEC.

Explanation: White lung disease, scientifically known as byssinosis, is an occupational lung disorder caused by prolonged inhalation of cotton dust in textile and cotton processing industries. The inhaled dust irritates the airways, leading to symptoms such as chest tightness, cough, wheezing, and shortness of breath. Long-term exposure can result in chronic bronchitis and reduced lung capacity.

Preventive Measures:

• Proper ventilation and dust control in textile mills
• Use of protective masks by workers
• Regular health check-ups and dust monitoring

Explanation: Haemoglobin is a complex iron-containing protein found in red blood cells (RBCs). It binds with oxygen in the lungs to form oxyhaemoglobin and releases it in tissues where oxygen levels are low. It also helps transport carbon dioxide from tissues back to the lungs. This oxygen-carrying property makes haemoglobin the essential respiratory pigment in humans and most vertebrates.

Explanation: In a healthy adult, the total volume of blood in the body is approximately 7% of body weight. For an average person weighing around 70 kg, this equals about 5 to 5.5 litres of blood. Blood plays a vital role in transporting oxygen, nutrients, hormones, and waste products throughout the body. It also helps regulate temperature and maintain pH balance. The major components of blood are plasma (55%), red blood cells (RBCs), white blood cells (WBCs), and platelets.

The Biome is the largest ecological unit. It includes several ecosystems that share similar climate, vegetation, and animal life. Examples include tundra, desert, rainforest, and grassland. A biome represents a major community of living organisms adapted to a specific environment over large geographical areas.

• Organism: An individual living being.
• Population: A group of the same species living in an area.
• Ecosystem: Includes both living and non-living components, but multiple ecosystems together form a biome.

Explanation: Rakesh Sharma was the first Indian astronaut to travel into space. He flew aboard the Soviet spacecraft Soyuz T-11 on April 3, 1984, as part of a joint mission between ISRO (Indian Space Research Organisation) and the Soviet Intercosmos program. During his space mission, he spent about 8 days aboard the Salyut-7 space station. When asked by then Prime Minister Indira Gandhi how India looked from space, he famously replied, “Saare Jahan Se Achha.”

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.