UPPSC Prelims 2008 Science and Technology Questions with Solutions

Explanation

RADAR, which stands for Radio Detection and Ranging, is an electromagnetic system designed to detect, locate, and track objects such as aircraft, ships, and spacecraft. It works by emitting pulses of radio waves into the atmosphere. When these waves encounter an object, they are reflected back toward the radar unit. By measuring the time delay between the transmission of the pulse and the reception of its echo, the system can calculate the distance to the target using the constant speed of light. The range R is determined by the formula R = (c · t)/2, where c is the speed of light and t is the round-trip time of the signal. Additionally, the direction of the returning signal helps determine the object's bearing and elevation relative to the radar station.

Explanation

The Science and Technology Policy 2003 was formulated with the aim of integrating science and technology into all spheres of national activity. One of its primary objectives is the optimal utilization of existing physical and knowledge resources to ensure that current infrastructure is used to its full potential. The policy strongly emphasizes the development of innovative technologies and the creation of a robust innovation system to enhance national competitiveness. It also specifically addresses the use of scientific knowledge and technological tools for the mitigation and management of natural hazards to reduce the impact of disasters. Furthermore, the management of intellectual property is a key pillar of the policy, focusing on establishing a comprehensive IPR regime that encourages creativity, protects indigenous knowledge, and ensures that the benefits of research reach the public. These components together form a holistic approach to science-led development in India.

Explanation

The Human Genome Project was a globally coordinated scientific effort that aimed to sequence the entire human genome and map the location of every gene. Launched in 1990 and completed in 2003, it involved determining the precise order of the 3 billion chemical base pairs that constitute human DNA. The project identified the full set of human genes, estimated at roughly 20,000 to 25,000, and established a reference sequence that serves as a blueprint for understanding human biology. This genetic mapping is critical for identifying the causes of genetic disorders and developing advanced biotechnological tools for diagnosis and treatment.

Explanation

Electric motors are designed to perform mechanical work, and the power P required to maintain a constant load is roughly the product of the supply voltage V and the current I, represented by the relation P = V ⋅ I ⋅ cos φ (where cos φ is the power factor). When the operating voltage drops, the motor must draw a higher current to provide the necessary power to keep the motor running against its load, making the current inversely proportional to the voltage (I ∝ 1/V). According to Joule's Law of Heating, the heat generated in the motor windings is given by H = I² R t, where R is the resistance of the windings. Since the heat produced increases with the square of the current, the surge in current caused by low voltage leads to excessive thermal energy that can melt the insulation and result in the motor burning out.

Explanation

Minamata disease is a neurological syndrome caused by severe mercury poisoning, specifically from methylmercury. The outbreak in Minamata City, Japan, resulted from the discharge of industrial wastewater containing methylmercury by the Chisso Corporation's chemical factory into Minamata Bay. This highly toxic organic mercury compound bioaccumulated and biomagnified within the local marine food web, particularly in fish and shellfish. When the local population consumed these contaminated aquatic organisms, the mercury entered their systems, leading to symptoms such as ataxia, numbness in the hands and feet, muscle weakness, narrowing of the field of vision, and damage to hearing and speech. The incident remains one of the most prominent examples of large-scale environmental health disasters caused by industrial heavy metal pollution.

Explanation

Bone marrow-derived stem cells are a type of adult or somatic stem cell that can be harvested from a living donor through a medical procedure. Unlike embryonic stem cells, which involve the destruction of a human embryo and thus trigger significant ethical and religious debates regarding the sanctity of life, the extraction of bone marrow cells does not result in the loss of life. These cells are obtained with the informed consent of the donor and have been used safely for decades in clinical treatments like hematopoietic stem cell transplants for leukemia and other blood disorders. Because they bypass the moral concerns associated with the destruction of potential human life, they are considered a bioethically non-controversial source for regenerative medicine and research.

Explanation

Radioactive dating, also known as radiometric dating, is a geochronological technique used to determine the absolute age of materials such as rocks and minerals. The process relies on the principle of radioactive decay, where unstable parent isotopes transform into stable daughter isotopes at a constant and predictable rate known as the half-life. By measuring the ratio of the remaining parent isotope to the accumulated daughter isotope within a sample, scientists can calculate the amount of time that has elapsed since the mineral formed or solidified. Common isotopic systems used for dating rocks include uranium-lead (U-Pb), potassium-argon (K-Ar), and rubidium-strontium (Rb-Sr), which allow for the precise measurement of geological time scales ranging from thousands to billions of years.

Explanation

Eklavya Technology Channel was inaugurated on January 26, 2003, as a specialized educational media initiative by the Ministry of Human Resource Development in collaboration with the Indian Institutes of Technology (IITs). Operating as a part of the Gyan Darshan network, the channel was specifically designed to broadcast high-quality engineering and technology programs. It featured recorded lectures from the IITs, covering a wide range of technical subjects to assist students in regional colleges and remote areas in accessing elite-level curriculum and instructional material. The channel played a critical role in the distance education framework for technical studies during that period.

Explanation

Soil particles, including suspended particulate matter and dust, act as physical irritants to the respiratory system. When inhaled, these particles lodge in the lungs and airways, triggering inflammation and causing various ailments related to breathing, such as bronchitis, asthma, and reduced lung capacity.

Lead is a potent heavy metal and neurotoxin that accumulates in the body over time. It can cross the blood-brain barrier and cause significant damage to the central nervous system, leading to cognitive impairment, behavioral issues, and physical coordination problems, particularly in children.

Carbon monoxide is a toxic gas that binds to hemoglobin with a much higher affinity than oxygen, forming carboxyhemoglobin. This process reduces the oxygen-carrying capacity of the blood, leading to systemic hypoxia. While its acute effects involve the heart and brain, the resulting lack of oxygen to vital tissues can cause cumulative damage to the liver and kidney.

Explanation

A-3: A stethoscope is an acoustic medical instrument used to listen to the internal sounds of the heart and lungs. B-4: A sphygmomanometer is the standard medical device used to measure arterial blood pressure. C-2: A caratometer is a specialized tool used to verify the purity of gold by determining its carat value. D-1: A lux meter is a device used to measure the intensity of light or the illuminance level on a surface.

Explanation

The Indian Institute of Sugarcane Research (IISR) is a premier agricultural research institution located in Lucknow, Uttar Pradesh. Established in 1952, it functions as a constituent laboratory under the administrative control of the Indian Council of Agricultural Research (ICAR), which is an autonomous body under the Ministry of Agriculture and Farmers Welfare. The institute is primarily responsible for conducting basic and applied research on all aspects of sugarcane culture and coordinating sugarcane research at the national level. Because its governance and funding are managed by ICAR, it is classified as an agricultural research institute rather than a member of the Council of Scientific and Industrial Research (CSIR) network.

Explanation

Coal is a primary source for producing carbon-based storage materials, such as activated carbon and carbon nanotubes, which are used for hydrogen adsorption. In this storage mechanism, hydrogen gas is absorbed onto the high surface area of the carbon structure at very low temperatures through physisorption. As the vehicle runs, the thermal energy generated by the exhaust system is utilized to heat the carbon material, triggering the desorption and release of the hydrogen gas to be used as fuel. Given India's vast domestic coal reserves, research has extensively focused on coal-derived carbon as a viable and accessible medium for hydrogen-powered transportation systems.

Explanation

Carbon monoxide binds to the iron atoms in haemoglobin to form carboxyhaemoglobin. This complex is extremely stable because carbon monoxide has an affinity for haemoglobin that is approximately 200 to 250 times stronger than that of oxygen. Unlike the transient and reversible binding of oxygen, the formation of carboxyhaemoglobin is functionally irreversible under normal physiological conditions. This high-affinity bond prevents the haemoglobin from transporting and releasing oxygen to the body's tissues, effectively reducing the oxygen-carrying capacity of the blood and leading to cellular hypoxia.

Explanation

The femur, or thigh bone, is the longest, heaviest, and strongest bone in the human body, extending from the hip to the knee and acting as the primary support for body weight during standing and locomotion. Cholera is an acute diarrheal infection caused by the bacterium Vibrio cholerae. It is typically transmitted through the consumption of contaminated water or food. Once inside the host, the bacteria produce an enterotoxin in the small intestine that causes the secretion of massive amounts of fluid and salts, leading to severe dehydration. These descriptions accurately characterize the anatomical status of the femur and the bacterial etiology of cholera.

Explanation

DNA is present in the nucleus of almost every cell in the human body, and forensic scientists can extract it from various biological materials found at a crime scene. Blood is a primary source because white blood cells, known as leukocytes, contain nuclei, even though mature red blood cells do not. Saliva is an effective source for testing because it contains nucleated epithelial cells that are naturally shed from the inner lining of the mouth. Hair can be used for DNA testing if the root or follicle is present, as it contains nuclear DNA, whereas the hair shaft primarily contains mitochondrial DNA. Semen is also a significant source of genetic material because it contains spermatozoa, which are rich in nuclear DNA. Since all these biological samples contain the unique genetic code of an individual, they are all valid sources for DNA profiling and identification in criminal investigations.

Explanation

A refrigerator operates as a heat pump that transfers thermal energy from its interior to the external environment. According to the First Law of Thermodynamics, the total heat rejected by the refrigerator into the room (Qₕₒₜ) is equal to the heat absorbed from the cold compartment (Q꜀ₒₗ₀) plus the work (W) done by the compressor motor, represented by the equation Qₕₒₜ = Q꜀ₒₗ₀ + W. When the door is left open, the refrigerator attempts to cool the entire room, which is an impossible task for its cooling capacity, causing the compressor to run continuously. Although the front of the refrigerator absorbs heat from the room air, the condenser coils at the back release both that absorbed heat and the heat equivalent of the electrical energy consumed by the motor. Consequently, the net energy added to the room is equal to the electrical work done by the compressor, which leads to an overall increase in the room temperature.

Explanation

The heart functions through a continuous series of events known as the cardiac cycle, which consists of systole (contraction) and diastole (relaxation). Although the heart is an involuntary muscle that works throughout an individual's lifetime, it does not remain in a constant state of contraction. During the phase of diastole, particularly the joint diastole, the heart muscles relax to allow the chambers to refill with blood. This brief period of relaxation occurring between the completion of one heartbeat and the start of the next is the time when the cardiac muscle rests. In a healthy adult with a heart rate of approximately 72 beats per minute, each cardiac cycle lasts about 0.8 seconds, providing these critical momentary intervals of rest within every cycle.

Explanation

Brazil had not developed or successfully deployed cryogenic engine technology by 2008. Cryogenic propulsion involves the use of liquid oxygen at -183 degrees Celsius and liquid hydrogen at -253 degrees Celsius as propellants, requiring highly advanced metallurgy, precision engineering for high-speed turbopumps, and complex thermal insulation systems. Brazil's national space efforts, primarily managed through the Brazilian Space Agency (AEB) and the VLS (Veículo Lançador de Satélites) program, were historically centered on solid-propellant rocket motors. The immense technical hurdles, high costs, and international export controls on sensitive dual-use technologies prevented Brazil from mastering the indigenous production and operation of cryogenic rocket stages during this period.

Explanation

The drying of wet clothes is a process of evaporation, where liquid water transitions into water vapor. The rate of evaporation is directly proportional to the temperature and inversely proportional to the relative humidity of the surrounding atmosphere. A high temperature of 60°C provides significant thermal energy to the water molecules, increasing their kinetic energy and allowing them to escape the liquid surface more readily. Concurrently, a low relative humidity of 20% ensures that the air is far from its saturation point, maintaining a steep vapor pressure gradient between the wet cloth and the air. This combination of high thermal energy and a high capacity for the air to absorb additional moisture results in the fastest possible evaporation.

Explanation

Meningitis is a medical condition characterized by the inflammation and swelling of the meninges, which are the three protective membranes—the dura mater, arachnoid mater, and pia mater—that envelop the brain and spinal cord. This inflammation is most commonly caused by an infection of the cerebrospinal fluid by bacteria, viruses, or fungi. Because the meninges serve as a vital barrier for the central nervous system, their swelling triggers clinical symptoms such as severe headache, fever, and neck stiffness, and can lead to serious neurological damage if the pressure on the underlying neural tissues is not relieved.

Explanation

Hindustan Aeronautics Limited (HAL) is India's premier state-owned aerospace and defense company, headquartered in Bengaluru. Established in its modern form in 1964 through the merger of Hindustan Aircraft Limited and Aeronautics India Limited, it operates under the management of the Indian Ministry of Defence. HAL is primarily involved in the design, fabrication, and assembly of aircraft, jet engines, helicopters, and their spare parts. By 2008, HAL had established a significant track record of manufacturing indigenous platforms such as the HF-24 Marut, the Dhruv Advanced Light Helicopter, and the Tejas Light Combat Aircraft, while also conducting extensive licensed production of international aircraft including the MiG-21, Jaguar, and Sukhoi Su-30MKI.

Explanation

The Main Asteroid Belt is a region of space located between the orbits of Mars and Jupiter. It contains the vast majority of asteroids in our solar system, which are rocky, airless remnants left over from the early formation of the solar system about 4.6 billion years ago. The gravitational pull of Jupiter prevented these fragments from accreting into a larger planetary body, resulting in a collection of millions of objects ranging in size from tiny dust particles to the dwarf planet Ceres, which is approximately 950 kilometers in diameter.

Explanation

The National Environmental Engineering Research Institute (NEERI) is a constituent laboratory of the Council of Scientific and Industrial Research (CSIR). It was established at Nagpur in 1958 as the Central Public Health Engineering Research Institute (CPHERI) and was later renamed NEERI in 1974. The institute focuses on research and developmental studies in environmental science and engineering, including water supply, sewage disposal, and air pollution management. Nagpur serves as the national headquarters for the organization, supported by five zonal laboratories located in other major Indian cities.

Explanation

The Shenzhou-7 mission was manned by a crew of three astronauts: Zhai Zhigang, Liu Boming, and Jing Haipeng. Launched in September 2008, it was China's third human spaceflight and the first to utilize the full three-person capacity of the Shenzhou spacecraft. The mission profile required exactly three crew members to conduct the first Chinese extravehicular activity, as one astronaut performed the spacewalk, a second assisted from the depressurized orbital module, and a third remained in the re-entry module to monitor vital spacecraft systems.

Explanation

The expression x⁻¹ - 1 can be simplified by converting the negative exponent into a fraction, giving 1/x - 1. Combining these terms over a common denominator yields (1 - x)/x. To find the quotient when this is divided by x - 1, we perform the division:

(1 - x)/x ÷ (x - 1) = (1 - x)/(x(x - 1))

In the numerator, 1 - x can be factored as -(x - 1). Substituting this into the fraction allows for the cancellation of the common binomial factor in the numerator and denominator:

(-(x - 1))/(x(x - 1)) = -1/x

Explanation

The given series is composed of pairs of squares and cubes of consecutive integers starting from 2. The sequence follows the mathematical pattern n², n³ for n = 2, 3, 4, 5, …. Breaking down the series, we find the first pair is 2² = 4 and 2³ = 8, the second pair is 3² = 9 and 3³ = 27, and the third pair is 4² = 16 and 4³ = 64. Following this established progression, the next pair must be based on n = 5, consisting of 5² and 5³. Since the last number in the series is 5³ = 125, the missing number immediately preceding it is 5² = 25.

Explanation

The sequence follows a pattern based on the alphabetical positions of the prefix letters and the cubes of those positions. The prefix letters correspond to the odd-numbered positions in the alphabet: a is the 1st letter, c is the 3rd letter, e is the 5th letter, and g is the 7th letter. This identifies the value of X as g.

The numerical values in the sequence are derived from these alphabetical positions (n). For the first term, 1³ = 1. For the third term, 5³ = 125. Following this progression of odd-numbered bases, the numerical value for the fourth term is 7³ = 343. Although the second term (3² = 9) uses a square, the relationship between the 7th letter g and its cubic value 343 is the defining pattern that identifies X = g and Y = 343.

Explanation

The longest pole that can be placed in a rectangular room (cuboid) corresponds to the space diagonal of the room. The length of this diagonal is calculated using the formula D = √(l² + b² + h²), where l is the length, b is the breadth, and h is the height of the room.

Substituting the given values: l = 12 m b = 9 m h = 8 m

D = √(12² + 9² + 8²) D = √(144 + 81 + 64) D = √289 D = 17 m

The space diagonal represents the straight-line distance between two opposite vertices of the cuboid that are not on the same face, providing the maximum length available for any rigid object like a bamboo pole.

Explanation

Electric trains are powered by electricity supplied through overhead lines or a third rail rather than by burning fuel like coal or diesel within the locomotive itself. Since there is no internal combustion or steam generation process occurring in an electric engine, the train does not produce any smoke. Therefore, regardless of the direction in which the train is traveling or the prevailing wind conditions, there will be no smoke to observe.

Explanation

The coding scheme uses an increasing arithmetic progression for letter shifts. Each letter in the word is replaced by a letter that is shifted forward in the alphabet by an incrementing value, starting from a shift of 2 for the first letter and increasing by 1 for each subsequent position. For the word PRINT, the transformation is calculated as P + 2 = R, R + 3 = U, I + 4 = M, N + 5 = S, and T + 6 = Z.

Applying this same logical pattern of +2, +3, +4, +5, and +6 to the word DRINK, we calculate the shifts as follows: the first letter D (4th position) shifted by 2 becomes F (6th position), the second letter R (18th position) shifted by 3 becomes U (21st position), the third letter I (9th position) shifted by 4 becomes M (13th position), the fourth letter N (14th position) shifted by 5 becomes S (19th position), and the fifth letter K (11th position) shifted by 6 becomes Q (17th position). This sequence of transformations results in the code FUMSQ.

Explanation

The sequence follows the general term formula aₙ = n³ - n², where n represents the position of the term in the series. Applying this formula for the given terms: the first term is 1³ - 1² = 0, the second term is 2³ - 2² = 4, the third term is 3³ - 3² = 18, the fourth term is 4³ - 4² = 48, and the fifth term is 5³ - 5² = 100. To determine the missing sixth term in the sequence, the same logic is applied for n = 6, resulting in 6³ - 6² = 216 - 36 = 180. This pattern can also be observed through the relation n²(n - 1), which for the sixth term yields 6² × (6 - 1) = 36 × 5 = 180.

Explanation

Serena Williams won the 2008 U.S. Open Women's Singles title by defeating Jelena Jankovic in the final with a score of 6–4, 7–5. This victory marked her third U.S. Open championship and her ninth Grand Slam singles title overall. By winning the tournament without dropping a single set, she also reclaimed the world No. 1 ranking for the first time since 2003.

Explanation

The behavior of a lens depends on its shape and the relative refractive index of the lens material compared to the surrounding medium. According to the lens maker's formula, 1/f = (n₂/n₁ - 1) (1/R₁ - 1/R₂), where n₂ is the refractive index of the lens (air) and n₁ is the refractive index of the medium (water). Since the refractive index of air is approximately 1.0 and that of water is approximately 1.33, the ratio n₂/n₁ is less than 1, making the term (n₂/n₁ - 1) negative. Even though the air bubble has a double convex physical shape, this negative focal length causes it to diverge light rays passing through it. A lens that diverges light is functionally equivalent to a concave lens.

Explanation

Mercury is the innermost planet of our solar system and, along with Venus, lacks any natural satellites. The absence of moons around Mercury is primarily attributed to its close proximity to the Sun and its relatively small mass. The Sun's powerful gravitational pull and intense tidal forces create an environment where it is extremely difficult for a small planet like Mercury to capture or retain a satellite in a stable orbit. The region of space where a planet's gravity is strong enough to hold onto a moon is known as the Hill sphere, and for Mercury, this sphere is very small, making stable long-term orbits for satellites nearly impossible.

Explanation

Modern humans and gorillas are both members of the family Hominidae, which includes the great apes. Molecular and genetic evidence indicates that gorillas share approximately 98.4 percent of their DNA sequence with humans. This close relationship is a result of a common evolutionary lineage that diverged between 8 and 10 million years ago. The physiological and anatomical similarities, along with closely related protein structures and blood group systems, demonstrate that gorillas are the most genetically similar primates to humans among the species listed.

Explanation

Black heart in potatoes is a physiological disorder primarily caused by a lack of oxygen reaching the internal tissues of the tuber. This condition typically arises during storage or transit when potatoes are kept in poorly ventilated environments or in large, deep piles where gas exchange is restricted. High temperatures further aggravate the problem by increasing the metabolic respiration rate of the potato, which rapidly depletes the available oxygen (O₂) supply. As the internal cells suffocate due to hypoxia or anoxia, they undergo necrosis, leading to the characteristic dark brown or jet-black discoloration in the center of the tuber.

Explanation

Polycarbonate is a high-performance thermoplastic polymer widely utilized in the manufacturing of bullet-proof glass and protective shields. Its primary utility in ballistic applications stems from its exceptional impact resistance and toughness, which are significantly higher than those of standard glass or other common plastics. In the construction of bullet-resistant systems, layers of polycarbonate are typically laminated between sheets of glass or other specialized materials. This composite structure allows the glass to deform the projectile while the polycarbonate layer absorbs the resulting kinetic energy and prevents penetration. Due to its high strength and ability to withstand sudden, high-velocity impacts without shattering, polycarbonate is a standard material for security glazing in armored vehicles, banks, and protective visors.

Explanation

Atmospheric refraction occurs when light rays bend as they pass through layers of the Earth's atmosphere with varying densities. When the Sun or Moon is near the horizon, the light rays from its lower limb must travel through thicker and denser layers of air than the rays from its upper limb. Because the density gradient is steeper near the surface, the bottom edge of the celestial body is refracted upward more significantly than the top edge. This differential refraction causes a vertical compression of the image, making the vertical diameter appear shorter than the horizontal diameter. As a result, the circular disk of the Sun or Moon appears elliptical or oval to an observer on the ground.

Explanation

Optical fiber communication relies on the principle of total internal reflection to transmit data as light pulses. An optical fiber consists of a core with a higher refractive index n₁ surrounded by a cladding layer with a lower refractive index n₂. When light signals enter the core and strike the core-cladding interface at an angle of incidence greater than the critical angle θ꜀, defined by the relation sin θ꜀ = n₂ / n₁, the light is reflected entirely back into the core. This process allows the signal to propagate through the fiber over long distances by undergoing a continuous series of reflections along the inner walls, maintaining signal strength and enabling high-speed data transfer.

Explanation

An Electroencephalogram (EEG) is a medical test used to evaluate the electrical activity in the brain. Brain cells, known as neurons, communicate with each other through electrical impulses that are active even during sleep. This activity is detected by small metal discs called electrodes that are attached to the scalp. The electrodes pick up the tiny electrical charges that result from the activity of the brain cells and transmit them to a machine that records the results as wavy lines on a graph. Clinically, the EEG is a vital diagnostic tool for identifying neurological conditions such as epilepsy, seizure disorders, sleep abnormalities, and brain damage. It provides a real-time record of the brain's functional state by measuring voltage fluctuations resulting from ionic current within the neurons.

Explanation

Japanese encephalitis is caused by the Japanese encephalitis virus (JEV), which is a single-stranded RNA virus belonging to the genus Flavivirus and the family Flaviviridae. It is an arbovirus, meaning it is transmitted to humans through the bites of infected mosquitoes, primarily the Culex tritaeniorhynchus species. The virus maintains a transmission cycle between mosquitoes, pigs, and water birds. In humans, the virus can invade the central nervous system, leading to severe inflammation of the brain. It is the leading cause of vaccine-preventable viral encephalitis in many countries throughout Asia and the Western Pacific.

Explanation

Vitamin K is a fat-soluble vitamin that is essential for the synthesis of prothrombin and other blood-clotting factors (Factors VII, IX, and X) in the liver. Its primary physiological role is to ensure proper blood coagulation, and a deficiency leads to delayed clotting and increased risk of hemorrhage. The property of preventing sterilization is specifically associated with Vitamin E, which is often referred to as the anti-sterility vitamin because it supports reproductive health and prevents germinal epithelium degeneration. Vitamin K does not have a functional relationship with sterilization or fertility.

Explanation

Dialysis is a clinical purification technique used to perform the functions of a defective kidney by filtering waste products and excess water from the blood. The process utilizes a semipermeable membrane that separates the blood from a dialyzing solution. Osmosis is the fundamental physical process where solvent molecules, primarily water, move through this semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration. In a dialysis machine, this allows for the removal of excess fluid from the patient's bloodstream into the dialysate, helping to maintain the body's fluid balance and osmotic pressure which the failing kidneys can no longer regulate.

Explanation

Haemophilia is a sex-linked recessive genetic disorder characterized by the body's inability to produce specific blood-clotting factors, leading to prolonged bleeding from even minor injuries. The genes responsible for this condition are located on the X chromosome. Since males possess only one X chromosome (XY), inheriting a single defective gene results in the manifestation of the disease. Females, having two X chromosomes (XX), generally act as asymptomatic carriers if they inherit one defective gene, as the healthy gene on the complementary X chromosome compensates for the deficiency. This inheritance pattern, where the condition is linked to the sex chromosomes and predominantly affects one gender, classifies haemophilia as a sexually related genetic disease.

Explanation

Spiders are classified under the class Arachnida within the phylum Arthropoda, whereas insects belong to the class Insecta. The primary anatomical distinction lies in the number of legs and body segments. Insects are characterized by having six legs (three pairs) and three distinct body regions: the head, thorax, and abdomen. In contrast, spiders possess eight legs (four pairs) and their body is divided into only two segments: the cephalothorax and the abdomen. Furthermore, spiders lack the antennae and wings that are common features of the insect class.

Explanation

Casein is the primary phosphoprotein found in mammalian milk, accounting for approximately 80% of the total protein content in cow's milk and about 20% to 45% in human milk. It is a complete protein that provides all the essential amino acids required for human health, growth, and development. In its natural state, casein exists in milk as a stable suspension of colloidal particles called micelles, which are held together by calcium phosphate bridges. These micelles are responsible for the characteristic white, opaque appearance of milk. Casein is essential in the production of dairy products because it coagulates or precipitates when the acidity of milk increases or when specific enzymes like rennet are added, forming the structural basis of cheese and curd.

Explanation

Ethylene glycol is the primary chemical compound used in automotive cooling systems to act as an antifreeze agent. When mixed with water, it significantly lowers the freezing point of the coolant solution through the principle of freezing point depression. This prevents the liquid from solidifying into ice during cold weather, which provides the necessary ice resistance to protect the engine block and radiator from damage caused by the expansion of freezing water. Ethylene glycol is preferred for this application because it possesses a high boiling point and low vapor pressure, ensuring it remains effective across a wide range of operating temperatures without evaporating.

Explanation

The Indian Institute of Information Technology, Allahabad (IIIT-A) was established by the Ministry of Human Resource Development, Government of India, in 1999. It was set up as a center of excellence in the field of information technology and allied sciences to cater to the growing demand for skilled professionals in the global IT sector. The institute was granted the status of a Deemed University in 2000 and was later designated as an Institute of National Importance. Located in the Jhalwa area of Allahabad, it was the first central IIIT to be established in the state of Uttar Pradesh.

Explanation

The Indian Institute of Pulses Research (IIPR) is a flagship national institute established by the Indian Council of Agricultural Research (ICAR) to conduct basic, strategic, and applied research on major pulse crops. While pulse research originally began under a coordinated project in New Delhi in 1966, the headquarters were shifted to Kanpur in 1977. The facility was upgraded to the Directorate of Pulses Research in 1983 and later achieved the status of a national institute in 1993. It is situated in Kanpur, Uttar Pradesh, where it works on developing high-yielding varieties and sustainable production technologies to enhance pulse productivity across the country.