General Science — Past Papers — Part 1 MCQs with Explanations

Genetics: Study of heredity and variation in organisms. An Austrian monk who experimented with pea plants i n the 19th century is known as the "Father of Modern Genetics" Additional information Ecology: Study of organisms and their environment. Anatomy: Study of the structure of organisms. Evolution: Study of how living organisms change over generations.

The SI unit of energy is the Joule (J). It is the unit of energy, work, and heat. Additional information : 1 Joule (J) = 1 Newton × 1 meter Calorie – 1 cal = 4.184 J Kilowatt-hour (kWh) – 1 kWh = 3.6 × 10⁶ J Electronvolt (eV) – 1 eV ≈ 1.602 × 10⁻¹⁹ J Erg (CGS unit) – 1 erg = 10⁻⁷ J

Aeroplanes fly in the troposphere . It is the lowest layer of the Earth's atmosphere . It extending up to about 12 km (7.5 miles) above the Earth's surface. The troposphere is where weather occurs, and it's the layer where aircraft operate . It typically cruising at altitudes between 30,000 to 40,000 feet ( 9,100 to 12,200 meters ). Additional information : Stratosphere : Contains the ozone layer. Mesosphere : Most meteors burn up here. Thermosphere : Includes much of the ionosphere and auroras.

The part of the eye that controls the amount of light entering is the Iris . It adjusts the size of the pupil according to light intensity. In bright light, it reduces light entry; in dim light, it allows more light in. This process protects the retina and helps clear vision .

The modern periodic table arranges elements in order of increasing atomic number . The atomic number is the number of protons present in the nucleus of an atom. Elements with similar chemical properties are placed in the same group ( vertical column ). The modern periodic law was established by Henry Moseley .

Mars is known as the Red Planet due to its reddish appearance . Its surface contains iron oxide (rust) which gives it a red color . It is the 4th planet from the Sun in the solar system. Mars has two small moons: Phobos and Deimos. Mars is often called the “ planet of future exploration ”.

A rainbow forms when sunlight is refracted, reflected, and dispersed through water droplets in the atmosphere. Refraction bends the light, while dispersion separates it into seven colors , creating a rainbow.

The cerebellum controls balance, posture , and coordination of voluntary movements . It helps make movements smooth, precise, and properly coordinated . It is located at the back of the brain , beneath the cerebrum . Additional information : Cerebrum : Thinking, memory, intelligence, and voluntary actions. Thalamus : Relays most sensory information to the cerebral cortex. Medulla oblongata : Controls involuntary functions such as breathing and heartbeat.

The Moon is Earth’s only natural satellite . Diameter – 3,474 km Distance from Earth – 384,400 km Orbital period – 27.3 days Surface gravity – 1/6th of Earth First human landing – Apollo 11, 1969

Digestion is the process of breaking down large food particles into smaller, simpler substances. It enables the body to absorb nutrients from food. Digestion involves mechanical and chemical processes. The digestive system includes the mouth, stomach, and intestines . Additional information : Absorption : Movement of digested nutrients into the blood or lymph. Assimilation : Use of absorbed nutrients by body cells.

Flowers are the reproductive structures of plants. It is responsible for producing seeds and facilitating sexual reproduction. They contain the male and female reproductive organs. They are essential for the production of fruits and seeds.

Neurons are the basic structural and functional units of the nervous system. They are specialized nerve cells . They transmit electrical and chemical signals. They control communication in the body. Brain, spinal cord, and nerves are made up of neurons .

Scurvy Cause: Vitamin C (ascorbic acid) deficiency. Symptoms: Fatigue, weak and sore limbs, bleeding gums, easy bruising, delayed wound healing, and anemia. Additional information : Rickets : Caused by a deficiency in Vitamin D. Beriberi: Caused by a deficiency in Vitamin B1 (Thiamine). Night Blindness: Caused by a deficiency in Vitamin A.

In the Fahrenheit scale: The boiling point of water is 212°F The freezing point of water is 32°F Additional information : In the Celsius scale: Boiling point of water: 100°C Freezing point of water: 0°C

Gene Definition : Basic physical and functional unit of heredity Location: Found on chromosomes within DNA Function : Codes for proteins or RNA molecules that determine traits Types : Structural genes (proteins), regulatory genes (control expression) Inheritance : Passed from parents to offspring during reproduction

Mercury is closest to the sun . It is mostly made up of iron . It's surface covered with craters . It has no atmosphere and no moons . It's smallest planet.

A computer program that translates one program instruction at a time into machine language is called an Interpreter . Interpreters are commonly associated with languages such as Python, JavaScript, and BASIC . Additional information : Compiler : Translates the complete program before execution. Assembler : Converts assembly language into machine code. Machine Language : Uses binary instructions understood directly by the computer.

Vitamin B Complex deficiency , specifically Vitamin B1 (Thiamine) deficiency, can cause: Beriberi , a disease characterized by : Fatigue and weakness Nerve damage and pain Heart problems Swelling of legs and feet Additional information : Vitamin B3 (Niacin) deficiency → Pellagra Vitamin B12 deficiency → Megaloblastic anemia and neurological problems

Total bones in adult human body = 206 At birth = 270–300 bones ( fuse to become 206 ) The total bones of our body can be divided into: Axial skeleton = 80 bones Appendicular skeleton = 126 bones Additional information : Newborn baby has 300 bones Longest bone = Femur Shortest bone = Stapes Bones in human skull = 22

A Barometer is an instrument used to measure air ( atmospheric ) pressure . It helps in weather forecasting by measuring changes in atmospheric pressure. The mercury barometer is the oldest type of barometer. It was invented by Evangelista Torricelli in 1643 . Barometers are widely used in meteorology and aviation .

Carbon dioxide (CO₂) — the main greenhouse gas causing global warming. Additional information: Methane (CH₄) — potent, from livestock and fossil fuels. Nitrous oxide (N₂O) — from fertilizers and industry. Water vapor — natural, amplifies warming. Fluorinated gases — synthetic, very strong effect. Last updated NA on 10-09-2026

The normal body temperature is: 37°C. The average normal body temperature is generally accepted as 98.6°F (37°C) . A temperature over 100.4°F (38°C) means you have a fever. Additional Information : Hypothermia is the term used for temperature less than 36.50°C. Mild Pyrexia is the term used for temperature (99-100°F). Moderate Pyrexia is the term used for temperature (100-103°F). Severe Pyrexia is the term used for temperature (103-105°F).

The unit of pressure is N/m² ( Newton per square meter ). It is also called Pascal (Pa) . Pressure means force applied per unit area . Higher force or smaller area increases pressure.

MRI stands for Magnetic Resonance Imaging . It is a medical imaging technique. It uses strong magnetic fields and radio waves to create detailed images of organs and tissues.

Main Cause: Freon / CFCs Effect: Breaks down O₃ molecules → more UV-B radiation Other Contributors: Halons, carbon tetrachloride Result: Skin cancer, cataracts, climate impact Additional information : The Montreal Protocol (1987) aimed to reduce CFC emissions Ozone layer protects Earth from harmful ultraviolet rays

The skin is considered the largest organ of the human body . It covering an area of about 1.5-2 square meters ( 16-22 square feet ). It weighing around 3-4 kilograms ( 7-9 pounds ).

The value 332 m/s is measured under standard atmospheric conditions . Additional information : Speed of sound in air at 20°C ≈ 343 m/s . Speed of sound is faster in solids than liquids and gases . Examples: Air: ~332 m/s (0°C) Water : ~1,480 m/s Steel : ~5,100 m/s

Malaria is caused by the parasite Plasmodium . It is transmitted to humans through the bite of an infected female Anopheles mosquito . Malaria is a parasitic disease. It mainly affects the liver and red blood cells. Common symptoms include fever, chills, headache, and sweating .

The instrument used to measure temperature is called a thermometer . A thermometer shows how hot or cold an object or place is. Additional information : Barometer measures air pressure. Hygrometer measures humidity (moisture in air).

The SI unit of electric current is Ampere (A). Electric current measures the flow of electric charge . Defined using the elementary charge (e = 1.602176634 × 10⁻¹⁹ C ). Named after: André-Marie Ampère (scientist). 1 Ampere = 1 Coulomb per second (1 A = 1 C/s).

Tally (accounting software) and MS Office are application software, Designed for user-specific tasks , not system software. Additional information System software includes: Assembler : Translates assembly language into machine code. Compiler : Translates high-level language into machine code. Interpreter : Directly executes high-level language code without compiling. Last updated 17 july 2026 by NA

Amino acids are the building blocks of proteins . Proteins are formed when amino acids join together by peptide bonds . Proteins are essential for growth, repair , and body functions . There are 20 standard amino acids used to make proteins. Verified & Updated

Navigation satellites are used to identify the location of objects on Earth . They provide position, navigation , and timing (PNT) services . These satellites help determine the exact location of people, vehicles, ships, and aircraft . They are widely used for navigation, mapping, and tracking. The most well-known navigation satellite system is GPS (Global Positioning System).

Sound waves in solvents (like liquids) travel as longitudinal waves , where particles vibrate parallel to the direction of wave propagation. These are a type of mechanical wave , requiring a medium to travel.

Sputnik-1 was launched by the USSR ( Soviet Union ) on 4 October 1957 . It was the world's first artificial satellite, beginning of the Space Age . It started the Space Race between the Soviet Union and the United States . Launch Site: Baikonur Cosmodrome, Kazakhstan Weight: 83.6 kg Orbital Period: About 96 minutes

Fission is the process in which a heavy atomic nucleus splits into two or more smaller nuclei , releasing a large amount of energy. It usually occurs when a heavy nucleus, such as Uranium-235 or Plutonium-239 , absorbs a neutron. The process also releases additional neutrons , which can start a chain reaction. Nuclear fission is used in nuclear power plants and atomic bombs .

Boiling point of water: 100°C Freezing point of water: 0°C Standard atmospheric pressure: 1 atm (760 mmHg) 0°C = 32°F 100°C = 212°F

Zero error is a Systematic error because it causes a consistent error in every measurement. It occurs when an instrument does not read zero even when no quantity is being measured. The same error is repeated in all readings unless corrected. Zero error may be positive or negative . It can be corrected by applying a zero correction .

Convex lenses are known as Converging lenses . Because they bring parallel light rays to a single focal point. A convex lens is thicker at the center and thinner at the edges. It forms real and inverted images when the object is beyond the focal length. It can also produce a virtual, erect, and magnified image when the object is placed within the focal length. Additional information : Concave lens is also called a diverging lens .

Sound cannot travel through a vacuum because there are no particles to carry sound vibrations. Sound needs a medium such as a solid, liquid, or gas to travel . Since space is nearly a vacuum , sound cannot be heard there. The speed of sound in a vacuum is 0 m/s . Additional information : Infrasound: Below 20 Hz Audible sound: 20 Hz – 20,000 Hz (20 kHz) Ultrasound: Above 20 kHz Speed of sound in air: 343 m/s Speed of sound in water: 1,481 m/s