General Awareness Test - 4

Jaundice is caused by the buildup of bilirubin, a yellow pigment produced during the breakdown of red blood cells. The liver is responsible for processing and excreting bilirubin, so liver disease or dysfunction leads to jaundice as bilirubin accumulates in the blood and tissues.

Dr. Christiaan Barnard performed the first successful human-to-human heart transplant on December 3, 1967, in Cape Town, South Africa. The patient, Louis Washkansky, lived for 18 days after the surgery.

The lotus (Nelumbo nucifera) is officially designated as the national flower of India. It holds cultural and spiritual significance in Indian tradition, representing purity and rebirth, and is frequently depicted in ancient Indian art and mentioned in religious texts.

Vitamin B6 (pyridoxine) deficiency can cause microcytic hypochromic anemia due to its essential role in heme synthesis. It can also cause neurological symptoms like confusion, depression, and seizures. Rickets is caused by vitamin D deficiency, scurvy by vitamin C deficiency, and beri-beri by thiamine (B1) deficiency.

Yellow fever is primarily transmitted by the Aedes aegypti mosquito. Aedes mosquitoes are also responsible for transmitting other diseases including dengue, Zika, and chikungunya viruses. Anopheles transmits malaria, Culex transmits West Nile virus, and houseflies are mechanical vectors for bacterial diseases.

Carbon dioxide (CO2) is the primary greenhouse gas responsible for global warming, contributing about 76% of all greenhouse gas emissions from human activities. While CFCs are also greenhouse gases with high global warming potential, CO2 is by far the major one in terms of total emissions and overall impact.

Vitamin C is water-soluble and readily leaches out of vegetables when they are washed or cooked in water. Peeling vegetables exposes more surface area, and washing them afterward removes significant amounts of this water-soluble vitamin. Fat-soluble vitamins (A, D, E, K) are not removed by washing.

Comets are icy bodies that orbit the Sun in highly elliptical orbits. They develop characteristic tails (coma and tails) when they approach the Sun due to sublimation of ice and solar wind effects. Comets do not orbit planets like Earth, Venus, or Jupiter - those are solar system bodies, not the center of cometary orbits.

Pasteurization of milk typically involves heating to 63°C for 30 minutes (low-temperature long-time method) or 72°C for 15 seconds (high-temperature short-time method). The goal is to kill harmful bacteria while preserving nutritional quality and flavor.

The troposphere is the lowest layer of Earth's atmosphere, extending from the surface to about 10-15 km altitude. It contains approximately 75% of the atmosphere's mass and is where all weather phenomena occur. The stratosphere lies above it, followed by the mesosphere, thermosphere, and exosphere extending outward.

Steel is the most elastic material among the options. Elasticity is defined as the ability to return to original shape after deformation. While rubber stretches more easily, steel has a higher elastic modulus and can undergo larger stress while still returning to its original shape. Wet clay deforms plastically (permanently), and plastic shows viscoelastic behavior with hysteresis.

The most common form of color blindness is red-green color blindness (protanopia/deuteranopia). People with this condition have difficulty distinguishing between red and green wavelengths, effectively confusing these colors in their visual perception. While they don't literally 'see red as green,' green is the most reasonable answer among the options given this confusion.

When moving from bright sunlight to a dark room, the photopigments in the retina have been partially bleached by the intense light and need time to regenerate. This photochemical adaptation (dark adaptation) is the primary reason for temporary vision loss. While pupil dilation also occurs, it happens relatively quickly and contributes less to the adaptation process.

Birds (including peacocks and ostriches) lack teeth and have beaks instead. Tortoises, as reptiles, also lack teeth - they have sharp, keratinous beaks for biting food. Turtles similarly lack teeth, while alligators do have teeth. Cows, being mammals, have teeth for chewing. Therefore, only option A lists three animals that all naturally lack teeth.

The freezer is placed at the top because cold air is denser than warm air and naturally sinks. This placement facilitates convection currents throughout the refrigerator compartment - cold air sinks from the freezer, cooling the food below, while warmer air rises to be cooled again. This natural circulation helps maintain even temperature distribution.

'Lead pencils' contain no actual lead metal. They are made of graphite (a form of carbon) mixed with clay. The name originated historically when graphite was mistaken for a form of lead. Graphite is still sometimes called 'black lead' in certain contexts, but modern pencils contain 0% lead.

The swing of a spinning cricket ball is explained by Bernoulli's theorem. As the ball spins through the air, it creates a pressure difference between the two sides due to asymmetric airflow - faster-moving air on one side creates lower pressure, causing the ball to deviate (swing) in that direction. This is the same principle that explains lift on airplane wings.

Common salt (table salt) is chemically known as sodium chloride (NaCl). It is an ionic compound composed of sodium cations and chloride anions. Sodium nitrate is a different salt used in fertilizers and food preservation. Ammonium chloride has different applications. Calcium chloride is used for de-icing and dust control.

Edward Jenner developed the first smallpox vaccine (3). James Watson and Francis Crick discovered the DNA double helix structure (4). Karl Landsteiner discovered the ABO blood grouping system (1). Alexander Fleming discovered penicillin (2). The correct matching is therefore: Jenner-3, Watson-4, Landsteiner-1, Fleming-2, which corresponds to option C.

Vitamin B12, also known as cobalamin, is the only vitamin that contains cobalt as an essential component of its molecular structure. The cobalt atom sits at the center of the corrin ring and is crucial for B12's biological activity. Iron is important for hemoglobin, magnesium is a cofactor for many enzymes, and zinc is involved in immune function, but only cobalt is integral to vitamin B12.

Argon is the third most abundant gas in Earth's atmosphere (approximately 0.93% by volume), making it the most abundant noble/inert gas. Helium, neon, and krypton are also inert gases but exist only in trace amounts - helium at about 0.0005%, neon at 0.0018%, and krypton at about 0.0001%. Argon's abundance comes from the radioactive decay of potassium-40 in Earth's crust.

Magnesium is the only metal among these options that is commercially extracted from seawater on a large scale. The process involves electrolysis of magnesium chloride obtained from seawater, where magnesium is present at about 1.3 g/kg. Magnesium compounds are abundant in ocean water, while potassium comes primarily from mineral deposits (sylvite), aluminium from bauxite ore, and beryllium from bertrandite and beryl minerals.