Gk Question and Answer in Science

No. Question Answer

• 01 The theory of relativity was propounded by Albert Einstein
• 02 The principal metal used in manufacturing steel is Iron
• 03 An alimeter is used for measuring Altitude
• 04 Oology is the study of Birds eggs
• 05 Radioactivity was discovered by Henry Bacquerel
• 06 The metal used in storage batteries is Lead
• 07 The instrument used to measure the relative humidity of air is Hygrometer
• 08 Barometer was invented by Torricelli
• 09 The unit of power is Watt
• 10 Radium was discovered by Marie and Pierrie Curie
• 11 The existence of isotopes was discovered by Frederick Soddy
• 12 Dynamo was invented by Michael Faraday
• 13 The nuclear reactor was invented by Enrico Ferni
• 14 The law of gravitation was propounded by Sir Isaac Newton
• 15 Crescograph was invented by J.C.Bose
• 16 Crescograph is used to measure the Rate of growth of a plant
• 17 Galileo’s first scientific discovery was Pendulum
• 18 Microscope was invented by Aaton Van Leewen Hock
• 19 The scientist who is known as father of modern biology is Aristotle
• 20 The first person to see a cell under microscope was Robert Hooke
• 21 The smallest flowering plant is Worffia
• 22 The four blood groups were discovered by Karl Landsteiner
• 23 Sodium was discovered by Sir Humphry Davy
• 24 The atomic number of oxygen is Eight
• 25 The basic building blocks of proteins are Amino acids
• 26 The botanical name of the cotton plant is Gossipium Hirsutum
• 27 An Electroscope is used to Detect charges on a body
• 28 The unit of loudness is Phon
• 29 An ammeter is used to measure Electric current
• 30 Plant that eat insects are called Insectivorous plants
• 31 Fruits that are formed without fertilization are called Parthenocarpic
• 32 Plants that flower only once in their lifetime are called Mono carpic
• 33 The botanical name for rice is Oryza Sativa
• 34 Penicillin is obtained from Mould
• 35 The largest tree in the world is Seguoia Gigantica
• 36 Herpetology is the study of Reptiles
• 37 Entomology is the study of Insects
• 38 Ornithology is the study of Birds
• 39 Ichtyology is the study of Fishes
• 40 Osteology is the study of Bones
• 41 The botanical name for brinjal is Solanum melongenal
• 42 The botanical name for onion is Allium Cepa
• 43 The study of sound is called Acoustics
• 44 The study of heavenly bodies is called Astronomy
• 45 The study of tissues is called Histology
• 46 Electric Lamp was invented by Thomas alva Edison
• 47 The fear of crowd is called Ochlophobia
• 48 The fear of books is called Bibliophobia
• 49 The fear of going to bed is called Clinophobia
• 50 The symbol of gold is Au
• 51 The symbol of sodium is Na
• 52 The symbol of Sr stands for Strontium
• 53 The symbol Rb stands for Rubidium
• 54 The symbol Md stands for Mendelevium
• 55 Calcium sulphate is commonly called Plaster of Paris
• 56 Sodium carbonate is commonly called Washing Soda
• 57 Sodium chloride is commonly known as Common Salt
• 58 The chemical name of Chloroform is Trichloromethane
• 59 The chemical name of baking powder is Sodium bicarbonate
• 60 The chemical name of bleaching powder is Calcium hypochlorite
• 61 The formula HCL stands for Hydrochloric Acid
• 62 The formula H2SO4 stands for Sulphuric Acid
• 63 The formula CHCI3 stands for Trichloromethane
• 64 The formula H2O2 stands for Hydrogen peroxide
• 65 A fungus which can only survive on other living organisms is called Obligate Parasite
• 66 A plant which lives in the dark is called Scotophyte
• 67 A plant adapted to live in dry places is called a Xerophyte
• 68 A plant adapted for growth in water is called a Hydrophyte
• 69 Bifocal lens was invented by Benjamin Franklin
• 70 Cement was invented by Joseph Aspdin
• 71 Laser was invented by Dr.Charles H.Townes
• 72 Electromagnet was invented by William Sturgeon
• 73 Rayon was invented by Sir Joseph Swann
• 74 Thermostat is an instrument used for regulating Constant temperature
• 75 The science of organic forms and structures is known as Morphology
• 76 Phycology is the study of Algae
• 77 Tata Institute of Fundamental Research was established in 1945
• 78 CSIR stands for Council of Scientific and Industrial Research
• 79 ISRO stands for Indian Space Research Organisation
• 80 The first human being to land on moon was Neil Armstrong
• 81 The first Indian in space was Rakesh Sharma
• 82 ISAC stands for ISRO Satellite Centre
• 83 VSSC stands for Vikram Sarabhai space Centre
• 84 The headquarters of ISRO is located at Bangalore
• 85 VSSC is located at Thiruvananthapuram
• 86 ISAC is located at Bangalore
• 87 National Science Centre is located at New Delhi
• 88 Central Tobacco Research Institute is located at Rajahmundry
• 89 Indian Institute of Horticultural Research is located at Bangalore
• 90 The Atomic Energy Commission was set up in August 1948
• 91 The first Indian Satellite was Aryabhatta
• 92 The first Indian Satellite was launched in the year 1975
• 93 ASLV stands for Augmented Satellite Launch Vehicle
• 94 INSAT stands for Indian National Satellite
• 95 The fear of women is known as Gynophobia
• 96 The fear of men is known as Androphobia
• 97 The scientist who developed the Quantum theory was Max Plonck
• 98 The steam engine was invented by James Watt
• 99 The botanical name of tea is Camellia Sinensis
• 100 Logarithms were devised by John Napier
• 101 The acid used in a car battery is Sulphuric acid
• 102 The system for writing by blind people was invented by Louis Braille
• 103 The parachute was used for the first time by J.P.Blanchard
• 104 The German physicit who first demonstrated the existence of Radio waves was Henrich Hertz
• 105 The instrument that records the intensity of earthquakes is Seismograph
• 106 The laws of floating bodies was discovered by Archimedes
• 107 The density of milk is measured by a Lactometer
• 108 Fountain pen was invented by L.E.Waterman
• 109 The instrument used to measure the pressure of gases is the Monometer
• 110 Bhaskara I was a famous Astronomer
• 111 The first atomic power station established in India was the Tarapore Atomic Power Station
• 112 The role of heredity was demonstrated by Mendel
• 113 The instrument used to measure the concentration of salt water is the Salinometer
• 114 Spectroscopy is the study of Anders John Angstrom
• 115 Dactylography is the study of Finger Prints
• 116 A tangent galvanometer is used to study the Strength of direct current
• 117 The fruit of Oak is called Acron
• 118 ZETA stands for Zero Energy Thermonuclear Assembly
• 119 The formula C6H5OH stands for Phenol
• 120 Michael Faraday worked as an assistant under another scientist whose name was Sir Humphry Davy

• 121 Vulcanised rubber was invented by Charles Goodyear
• 122 The symbol Zn stands for Zinc
• 123 The symbol He stands for Helium
• 124 Celluloid was invented by A.Parker
• 125 Glider was invented by Sir George Caley
• 126 Safety matches was invented by J.E.Lundstrom
• 127 Radio valve was invented by Sir J.A.Fleming
• 128 Space Applications Centre is located at Ahmedabad
• 129 Atomic Energy Commission is located at Mumbai
• 130 Dynamics is the study of Movements of bodies
• 131 Statics is the study of Forces acting on bodies at rest
• 132 Mechanics is the study of Forces acting on bodies
• 133 Zoology is the study of Animal life
• 134 Botany is the study of Plant life
• 135 Psychology is the study of Human mind
• 136 The first American to orbit earth was John H.Glen
• 137 The electro-cardiograph was invented by William Einthoven
• 138 The molecular formula of cane sugar is C12H22O11
• 139 A compound which contains only hydrogen and Carbon is called a Hydrocarbon
• 140 The liquid used to preserve specimens of plans and animals is Formalin
• 141 The law of segregaton was propounded by Mendel
• 142 Auriscope is used to detect Ear disorders
• 143 The three states of matter are Solid,liquid and gas
• 144 The scientific name for blood platelets is Thrombocytes
• 145 The response of a plant to heat is called Thermotropism
• 146 The response of a plant to touch is called Trigmotropism
• 147 The symbol Zr stands for Zirconium
• 148 Nickel was discovered by Cronstledt
• 149 Manganese was discovered by Gahn
• 150 The common name for pottasium carbonate is Potash
• 151 Bismuth was discovered by Valentine
• 152 The biggest plant seed is Cocodemer
• 153 Toxicology is the study of Poisons
• 154 Virology is the study of Viruses
• 155 Paleontology is the study of Fossils
• 156 Calorimeter is used to measure Quantity of heat
• 157 Chronometer was invented by John Harrison
• 158 Stethoscope was invented by William Stockes
• 159 Spinning frame was invented by Sir Richard Arkwright
• 160 Al stands for Aluminium
• 161 Gd stands for Gadolinium
• 162 Ir stands for Iridium
• 163 Bi stands for Bismuth
• 164 The Chemical formula of sodium bicarbonate is NaHCO3
• 165 The chemical formula of common salt is Nacl
• 166 The chemical formula of washing soda is Na2CO3,IOH2O
• 167 The chemical formula of lime soda is CaCO3
• 168 The chemical formula of chloroform is CHcl3
• 169 The study of grasses is known as Agrostology
• 170 The study of antiquities is known as Archaeology
• 171 The study of the duration of life is known as Chronobiology
• 172 The study of bacteria is known as Bacteriology
• 173 Nylon was invented by Dr.Wallace H.Carothers
• 174 Electric razor was invented by Jacob Schick
• 175 The symbol of silver is Ag
• 176 The symbol of silicon is Si
• 177 The symbol of titanium is Ti
• 178 Calcium oxide is commonly known as Quick lime
• 179 A deviation of light passing from one medium to another is known as Refraction
• 180 An apparatus for generation of atomic energy is called a Reactor
• 181 A machine used for converting mechanical energy into electrical energy is called a Generator
• 182 The first Indian woman in space was Kalpana Chawla
• 183 The revolver was invented by Samuel Colt
• 184 The refrigerator was invented by J.Perkins
• 185 Which is the only common metal that is liquid at room temperature? Mercury
• 186 When a fire is caused by an electric short circuit, why must you not throw water? If you throw water on a fire caused due to short circuit, you may be electrocuted because water is a good conductor of electricity.
• 187 Why do we see lightning much before we hear thunder? This is because light travels much faster than sound. Light travels @ 2.99 x 108 mt / sec (2,99,000 km/sec) whereas sound travels @ 333 mt/sec.
• 188 Which planet is the closest to the Sun? Mercury
• 189 Which is the hottest planet? Venus
• 190 How much time does the earth take to complete a revolution around the sun? 365 % days.
• 191 Why are whales hunted? For the blubber or the oil in them.
• 192 Where do platypuses live? In burrows near water.
• 193 How many days does the moon take to go round the earth? 27 1/3 days.
• 194 Among the insects that are extant, (that are living still), which is the most ancient? Cockroach.
• 195 What is meant by fulcrum? Fulcrum is the point about which a bar or lever will rotate, when a force is applied at any distance from that point or axis.
• 196 What kind of leaves do silkworms thrive on? Mulberry leaves.
• 197 Why is it dangerous to look at die sun during an eclipse? During solar eclipse, the ultraviolet rays are in such high proportion in sunrays, that they can cause irrepairable damage to the eye.
• 198 How does a Pitcher Plant eat flies? A Pitcher Plant is hollow and tubular. The surfaces are slippery and they have hairs, which point downwards. When an insect lands on a pitcher plant, it is impossible for it to escape because of the slippery surface and the downward-pointed hairs. It is then easily digested.
• 199 What is the Indian name for the planet Mercury? Budha.
• 200 Where in India do the migratory cranes of Siberia settle down? The Rann of Kutch.
• 201 How many arms does a starfish have? Usually five.
• 202 What is a solar eclipse? The moon comes in between the sun and the earth, and thereby prevents sunlight from reaching the earth.
• 203 Who first saw mountains and craters on the moon using a telescope? Galileo Galilei
• 204 Which is the largest animal on land? African Elephant.
• 205 Why does a rhinoceros spend so much time in mud? To keep cool and protect itself from insect bites.
• 206 Which country first used fingerprints to identify people? Assyria and China.
• 207 In which country was silk first made? China.
• 208 What is cholesterol? Cholesterol is a fat found in the human body and the body of other large animals. In its pure form it looks like white sugar. It is made up of tiny crystals, which can be seen under a microscope. It is said that too much cholesterol in the blood is responsible for the hardening of arteries and for various other heart ailments.
• 209 How did the watch get its name? From the fact that you have to watch it to know the time.
• 210 What is vulcanisation of rubber? The process of hardening rubber by adding sulphur and heating the mixture is vulcanisation. Vulcanisation was discovered by Charles Goodyear. Raw rubber is sticky. It hardens when the temperature is low and softens when it is high. Charles Goodyear discovered that by combining raw rubber with sulphur and by heating it, the rubber becomes stronger and elastic and also resistant to solvents. Today almost all rubber, whether natural or synthetic is vulcanized.
• 211 When faced with danger what does a Pangolin do? It rolls into a ball.
• 212 Where is the entrance to a baya’s nest? At the bottom of the nest.
• 213 What is glass made from? Limestone, Silica and Soda ash.
• 214 What is the microscopic study of plant and animal tissue called? Histology.
• 215 How does a mariner’s compass help the mariner? The needle of the compass always points towards the magnetic north pole. This indicates the direction in which the ship is moving.
• 216 Which is the second largest planet in our Solar System? Saturn.
• 217 How many weeks after birth does the young one of a cat opens its eyes? Three weeks.
• 218 The arms of the Octopus have sucker cups. What is the use of these cups? To hold onto a surface.
• 219 What food does a bear love most? Honey.
• 220 How did the Romans rub off what was written on a wooden slate coated with wax? By heating the slate, the wax was melted. The slate became ready to reuse.
• 221 What are seashells? Outer casings of soft-bodied animals, called molluscs.
• 222 How is a pearl formed within the body of an oyster? A pearl is formed when a grain of sand or other foreign matter gets between the hard outer shell and the inner coat called the mantle, of a mollusc. The mollusc surrounds the irritation with nacre, a secretion from the mantle. Many thin layers of nacre give the pearl its lustre.
• 223 How much time does Pluto take to complete a revolution around the sun? 248 years.
• 224 What is a Catamaran? A boat with twin parallel hulls. [From the Tamil words katta and maram, meaning tied up (katta) tree (maram).
• 225 How many ears does a spider have? None.
• 226 How much time does light take to reach the earth from the sun? 8 minutes.
• 227 What is acceleration? The time rate at which the velocity of a point is changing is acceleration. Velocity is just the speed (miles per hour or kilometres per second). The term acceleration is used when the speed keeps increasing. The term deceleration is used when the speed becomes less and less.
• 228 How does a spider eat its food? The spider inserts his fangs into the victim’s body and uses them as straws to suck out the liquid.
• 229 Who invented the telescope? Hans Lippershey.
• 230 Why do people living in the deserts prefer white colour for their robes? White coloured robes do not absorb light, whereas dark-coloured clothes absorb the light and conduct heat to the body.
• 231 What is common to dolphins and humans? They are both mammals.
• 232 In which country was the day first divided into 12 parts? Babylon (modern Iraq).
• 233 How does a rocket move forward? It moves forward due to propulsion. You must have seen that a boatman pushes the water backwards with his oar. This creates a force in the forward direction. This is propulsion. Newton’s third law of motion states action and reaction are equal and opposite. In a rocket when hot gases come out of the rear with great force as a result of combustion, a force is created in the opposite direction. This takes the rocket forward.
• 234 What are the things necessary to start a fire? Heat, fuel and oxygen.
• 235 How many legs does a butterfly have? Six.
• 236 Who invented the aeroplane heavier than an air machine that could fly? Orville and Wilbur Wright.
• 237 Who invented the modern lift? Elisha Otis.
• 238 Why can’t cranes perch on trees branches? They cannot curl their toes. As a result they cannot have a firm grip on a branch.
• 239 Ancient Sumenans used to write on clay. How could this writing be preserved? By baking the tablets. This would remove the moisture from the tablets and harden them.
• 240 How big are the tusks of an Indian female elephant? Indian female elephants do not have tusks.
• 241 Bats cannot see. Then how do they move about? They emit sounds of low intensity, which are reflected from the objects around them. This helps the bats to move about.
• 242 How does a frog catch an insect? It throws out its tongue, which is sticky and catches the insects.
• 243 What is a Portuguese Man of War? A name commonly applied to jelly fish, found in tropical seas.
• 244 Why are oceans important to man? They enable man to travel to distant corners of the world. They also provide food, oil and minerals.
• 245 What is the transparent portion in front of the eyeball called? Cornea.
• 246 What is the meaning of the pecking order? Pecking order is an example of hierarchy among animals, particularly hens. In a coup containing hens and cocks, the seniormost cock can peck at all the other hens and cocks in the coup. A hen can peck at others weaker than it, but must permit pecking by senior members in the hierarchy.
• 247 Who made trains run by steam engine popular? George Stephenson
• 248 How are volcanoes caused? Deep under the crust of the earth is molten rock or lava, also called magma. It is under great pressure because of the intense heat around it and the weight of the earth’s crust. When this hot boiling mass finds an outlet in the underside of the earth’s crust, it comes through the surface as lava.
• 249 What is a male ant called? Drone.
• 250 How can a frog make such a loud sound? As the frog forces air from the lungs, vocal chords in the voice box (larynx) vibrate to make calls, distinctive of its species. The bulls of some species have air sacs, which help, increase the volume of the sound.
• 251 Who was the first man on the moon? Neil Armstrong.
• 252 What is peristalsis? Peristalsis is a type of movement occurring in the hollow organs of animals, which causes their contents to be pushed ahead.
• 253 What are the main differences between an Indian elephant and an African elephant? The African elephant is much larger in size. Its ears as well as tusks are larger than those of an Indian elephant.
• 254 What is it that silkworms weave around themselves? Cocoon.
• 255 Why did Dr. Lister use carbolic acid to cover wounds? To prevent infection.
• 256 What is the juice of the rubber plant called? Latex
• 257 Why does the ostrich eat sand or gravel? To digest its food.
• 258 Which discovery made soap-making a big industry? It was discovered (in 1787) that caustic soda can be made from common salt. Since soap is made from caustic soda and fat, manufacturing soap became cheaper.
• 259 Who invented the Gramophone? Thomas Alva Edison
• 260 Which is the largest living bird? Ostrich.
• 261 Why didn’t the British plant rubber in England? Rubber grows only in tropical countries.
• 262 Why do tigers turn into man-eaters? When tigers become old or are incapacitated because of injury, they prey on human beings. A tiger that has preyed on man and has tasted human flesh often continues to prey on man.
• 263 What was called Penny-farthing? The cycle whose front wheel was much larger than the rear wheel. It was invented by James Starley. It was derisively named penny-farthing after the largest and smallest English copper coins of the period.
• 264 Why does not the moon have an atmosphere? Even if it had some atmosphere, its mass is so low that gravity on the surface is not enough to retain the atmosphere.
• 265 Name the animal that has the largest eyes in the world? The Atlantic Giant Squid, about 30 cm wide.
• 266 Who invented the four-stroke Motorcar engine? Nikolaus Otto.
• 267 What are meteorites? They are rocks or pieces of rocks that enter the atmosphere and are usually burnt out before landing on earth. Some large meteorites can crash against the surface of the earth and cause damage.
• 268 What did ancient Romans think lightning was? Jupiter’s weapon.
• 269 Are the soldier ants male or female? They are all female.
• 270 What is the nest of a penguin made of? Pebbles.
• 271 What are the characteristics of a parasitic plant? They cannot produce their own food and obtain food from other sources.
• 272 What keeps the sun so hot? A reaction similar to that of a hydrogen bomb takes place continuously in the sun. Two atoms of hydrogen fuse at high temperatures to form an atom of helium. Immense heat is released in this reaction.
• 273 What is meant by Binary System? We carry out everyday calculations, using the decimal system, with the numbers 1 to 9 and zero. The binary system uses only two numbers 0 and 1. An electric current can be switched on and off using off for 0 and on for 1. Any number can be represented in the binary system.
• 274 Which was the first spaceship launched by man? Sputnik-I, launched by the Russians
• 275 What kind of nests do owls build? They don’t build nests. They use hollows in trees for laying eggs.
• 276 Why is polished rice less healthy than unpolished
• rice? The husk of food grains (rice, wheat, etc) has Vitamins, much of which are lost when the grains are polished.
• 277 Which Psychologist devised the IQ test? Alfred Binet.
• 278 Who discovered Radium? Pierre and Marie Curie.
• 279 What is the approximate temperature deep inside the sun? 14 million degrees C.
• 280 What are Epiphytic plants? Plants that grow on other plants for support. These plants however do not take nourishment from the host.
• 281 Sometimes the eagle spits out pellets from its mouth. What are they? Bones and fur of the prey that are left after the food is digested.
• 282 What does a ruminant mean? Ruminant is an animal that chews its cud and has a four-chambered stomach. When food is swallowed by a ruminant, it passes into the rumen or paunch, where it is stored, while the animal eats. Chewing and digestion are carried out at leisure. The food passes from the rumen to the reticulum, where it is formed into small masses and pushed up to the mouth to be chewed. When it is swallowed a second time it takes a different route. Gastric digestion takes place and the food passes into the intestine.
• 283 Who discovered the Planet Uranus? Sir William Herschel.
• 284 Who invented Television? John Logic Baird.
• 285 How do dolphins communicate with each other? By producing screeching sounds.
• 286 Who was the first woman to travel in space? Valentina Tereshkova.
• 287 What are clouds made of? Tiny droplets of ice or water.
• 288 What is the disease that causes dogs to turn mad? Rabies.
• 289 Who conducted the first controlled fission reaction (that led to the making of the atom bomb)? Enrico Fermi.
• 290 Which was the first satellite launched by India? Aryabhata, in 1975.
• 291 What is Dry Ice? Solid Carbon Dioxide.
• 292 Who invented the Radio? G. Marconi (Jagadis Chandra Bose has also been credited with this discovery but his claim has not been recognised).
• 293 What was the theory of the atom put forward by Rutherford? Rutherford put forward the theory that every atom consists of a tiny nucleus with a positive charge, surrounded by electrons. The electrons are far apart from the nucleus and from one another.
• 294 Of which element is diamond made of? Carbon.
• 295 The Pit Viper has poor eyesight. Yet it can locate its prey accurately. How? It has heat sensory cells in the pits between the eye and the nostril, which detect warm-blooded animals.
• 296 Who first propounded the theory of Evolution of Man? Charles Darwin.
• 297 From which elements is steel made? Iron and Carbon.
• 298 Which instrument is used for measuring humidity? Hygrometer.
• 299 If you speak loudly on the moon, approximately how far can your voice travel? Sound waves need a medium in which they can travel. The atmosphere on the moon is negligible. Hence your voice cannot travel any distance.
• 300 What is the difference between Toads and Frogs? Toads have a dry warty skin while frogs have a smooth moist skin.
• 301. Who first discovered that water was produced by burning hydrogen? Henry Cavendish.
• 302. What are the parts of a comet? Nucleus, coma and tail.
• 303 Why are the blades of the fan slightly curved? If you wish to carry sand or any solid substance from one place to another, you can carry little if there are straight metal strips. A pail can carry much more. In the case of air, which is a fluid, a slightly curved blade is enough to help circulate air in the room.
• 304 What is absolute zero temperature? Absolute zero is the temperature at which thermal energy (energy related to heat) vanishes. It corresponds to -273.15 degrees, on the Celsius scale.
• 305 Who is considered the father of plastic surgery in ancient India? Sushruta. He is best known for the operations he performed called rhinoplasty (remodelling of the nose).
• 306 What are isotopes? Isotopes are different forms of an element with the same number of protons, but a varying number of neutrons in the nucleus of an atom. All elements consist of atoms. Atoms have a nucleus, which consists of proton or protons and neutrons. They usually have as many electrons as protons, continuously whirling around the nucleus. Hydrogen has two naturally existing isotopes – one with only a proton and no neutron in its nucleus and another with a neutron and a proton. The first one is commonly known as hydrogen. The second one is rare and is called deuterium or heavy hydrogen. A third isotope, called tritium, is artificially produced. Tritium has one proton and two neutrons.
• 307 Who discovered the cause of malaria? Ronald Ross.
• 308 Which planet has a moon named Titan? Saturn.
• 309 Name the largest bone in the human body. Femur (in the thigh).
• 310 What is the source of all energy on earth? The sun.
• 311 What was the name of the instrument used by Jagadis Chandra Bose to measure sensitivity of plants? Crescograph.
• 312 How long do banyan trees live? Banyan trees seem to live for hundreds of years. Aerial roots develop from its branches and they take root in the soil. Over the years these roots turn into sturdy trunks, which too grow roots and the cycle continues. It is said that the entire army of Alexander had taken shelter under one such banyan tree.
• 313 Which part of the plant do you eat when you eat carrots? Roots.
• 314 Who was the first man to travel in space? Yuri Gagarin.
• 315 What is reinforced concrete? Reinforced concrete is ordinary concrete which has steel rods fixed in it.
• 316 What is meant by latent heat? Heat absorbed when a substance changes its state without changes in temperature, e.g. water boils at 100°C. When we heat it further the temperature is not raised but the heat is absorbed.
• 317 In ancient India shells of a sea-animal were used as money. What were they called? Cowries.
• 318 How does spraying kerosene on marshes reduce mosquitoes? A film of oil is produced which prevents the larvae of the mosquitoes from having access to the oxygen in the atmosphere.
• 319 How many bones are there in an adult human being? 206.
• 320 Who is considered to be the father of Geometry? Euclid.
• 321 What is the study of sound called? Acoustics.
• 322 Which was the first satellite India launched from Indian soil using an Indian launch vehicle, SLV3? Rohini Satellite (RSI).
• 323 What are bacteria? Where are they found? Bacteria formerly classified as plants are now classified separately as Prokaryotes. They are so small that we can see them only with a microscope. They are found almost everywhere. Bacteria cause and spread diseases, but there are many bacteria that are helpful to man. Bacteria are responsible for converting grape juice into wine and milk into curd.
• 324 What is the name of the instrument that records heart beat? Cardiograph.
• 325 Who discovered the connection between magnetism
• and electricity? Hans Christian Oersted.
• 326 Who discovered the presence of neutrons in the nucleus of elements? Physicist James Chadwick.
• 327 At what temperature does water become ice? Zero degrees on the Celsius scale.
• 328 What do deciduous trees mean? Trees that shed leaves in autumn are called deciduous trees.
• 329 The electric discharge of which fish is the most powerful? South American Electric Eel.
• 330 What is the name for power generated from water? Hydroelectricity.
• 331 How is sound produced? Basically sound is produced when a vibrating body sets air molecules in motion. Musical instruments produce sounds by vibrating strings. The vibration and waves that are produced reach the ear, which passes the vibrations to the brain. To test this take a steel tumbler and tap on it with a metallic spoon. Sound is produced. Hold the edge of the tumbler between two fingers. The sound stops. This illustrates the importance of vibration in producing sound.
• 332 How are motion pictures made? When the eyes see an image, they hold onto it in the form of a visual memory for a fraction of a second after it is gone. In a motion picture, the projector flashes still pictures quickly in succession. The usual numbers of pictures that are projected per second are 24. Because of persistence of vision, the picture seems to be one continuous moving picture.
• 333 From which part of the plant, is ginger that we eat obtained? From the stem.
• 334 Who was the first person to find out that microscopic organisms are responsible for milk, wine, etc turning sour? Louis Pasteur.
• 335 What is the meaning of the word Hippopotamus? River Horse.
• 336 Who invented the Hovercraft? Christopher Cockerell.
• 337 Who discovered Vitamins? Christopher Eijkman – though he did not use the word, vitamin.
• 338 Who coined the word Vitamin? CasimirFunk.
• 339 Why does the planet Mars appear red? Due to the highly oxidised surface of the planet.
• 340 Name the Vitamin that prevents night blindness. Vitamin A.
• 341 Where do sea plants obtain carbon dioxide to manufacture their food? From dissolved gases
• 342 Who is considered as the father of modern Medicine? Hippocrates.
• 343 How does an Octopus camouflage itself? By changing its colour and merging with the background.
• 344 Who first proved that lightning is an electric charge coming down to the earth? Benjamin Franklin.
• 345 What are cosmic rays? Cosmic rays are radiation from outer space, which bombard the earth. They constantly strike the molecules of the earth’s upper atmosphere. As a result, additional radiations are produced. The atmosphere absorbs most of these rays.
• 346 What is a cocoon? It is a silk case, that covers a caterpillar before it becomes a moth (butterfly). After the caterpillar is completely wrapped in its cocoon, it sleeps through the winter.
• 347 What does the acronym LASER stand for? Light Amplification by Simulated Emission of Radiation.
• 348 How is cement obtained? Heating a mixture of limestone and clay.
• 349 Name the only mammal, other than man, that can walk upright? Gibbon.
• 350 Which disease is caused by insufficiency of iodine in the diet? Goitre.
• 351 What are molluscs? A class of animals with a soft body and no bones.
• 352 Which animal has the longest life span? Tortoise.
• 353 How is the glow of a firefly caused? When certain proteins get oxidised, in the presence of an enzyme called luciferase, light is produced. Fireflies have special light organs on the underside of the abdomen. Here in the presence of luciferase, light is produced.
• 354 Who first enunciated the laws of heredity? Gregor Johann Mendel
• 355 What does the acronym, SONAR, stand for? Sound Navigation and Ranging.
• 356 What are comets? Comets are heavenly bodies that travel around the sun. When they are near the sun, they look like stars with long glowing tails. Halley’s comet appears once in about 76 – 78 years. Some comets appear near the sun only once in millions of years. A comet has a head, which looks like a star. The head is surrounded by a coma or a fuzzy hood. The tail may be millions of kilometres long.
• 357 Why does a metal rod feel cooler than a piece of wood? Metals are good conductors of heat. When we touch a metallic rod, it takes away the heat from the hand and feels cooler. A piece of wood is a bad conductor of heat and therefore it does not take away the heat from our hands.
• 358 Why does a jet of water come out of a whale’s back? It is air, exhaled by the whale.
• 359 How many teeth do sheep have on their upper jaw? None.
• 360 How are helicopters useful in rescue operations? A helicopter can move up, take off or land easily from small clear areas. Hence they are useful in dropping food or rescuing stranded people. It has a rotor, which enables it to rise up or go down, vertically.
• 361 How can lizards walk on walls? The base of their paws has cuplike structures that stick to the walls. This enables them to move even on walls.
• 362 How does a perfume spread to the corners of any room even though there is no breeze? Molecules of oxygen, nitrogen and other gases in the air keep on spreading all around them.
• 363 Where does light fall inside the eye? Retina.
• 364 Chlorine is very injurious to health. So is sodium. The table salt we use is sodium chloride. Why is it not dangerous to health? It must be noted that a compound formed from two or more elements need not have a single property of its constituent elements. Sodium and Chlorine combine to form table salt, which is healthy (in small amounts). Water, which sustains life, is formed from hydrogen and oxygen. The properties of hydrogen as well as oxygen are not found in water.
• 365 How does a frog breathe under water? Through its skin.
• 366 What is the difference between a tortoise and a turtle? Tortoise is the name applied to the terrestrial species and turtle is the name applied to the aquatic species.
• 367 What is meant by sublimation in chemistry? Conversion of a substance from solid state to vapour state (without the intervening liquid state) is sublimation. For example, iodine sublimates from its solid state to vapour.
• 368 What are the sieve like plates in a whale’s mouth called? Baleens.
• 369 Why do people cover ice slabs with sawdust? Sawdust is a bad conductor of heat and slows down the melting of ice.
• 370 Why are droplets formed on the outer surface of a glass when cold water is poured into it? The moisture in the air condenses on the cool outer surface of the glass.
• 371 Why is food preserved in a refrigerator? Most bacteria are destroyed as the temperature of the surroundings rises. Temperatures higher than 40° C do not favour growth of bacteria. Similarly low temperatures prevent bacteria from multiplying. Hence food is preserved in the refrigerator by keeping its contents at low temperature.
• 372 Why do we feel sleepy after a heavy meal? The blood circulation to the digestive tract increases. As a result the blood circulation to the brain is reduced. This makes us sleepy.
• 373 Which organs in the human body filter waste products from the blood? Kidneys.
• 374 Which organs are most damaged when a person consumes much liquor? Liver and stomach.
• 375 What does Aurora mean? Bright patches of light are seen at high latitudes above 60° north or south. They are named Aurora Borealis (northern lights) or Aurora Australis (southern lights) depending on their position. The term “Aurora Polaris”, polar lights, is a general name for both. The aurora consists of rapidly shifting patches and dancing columns of light of various hues.
• 376 Which vitamins are soluble in water? Vitamins of the B and C group.
• 377 What is the composition of perspiration? Mostly water with a little salt.
• 378 Which gland in the human body produces insulin? Pancreas.
• 379 What is the principal enzyme in the gastric juice? Pepsin.
• 380 What is the vaccination given to prevent polio? Salk Vaccine. It was discovered by Jonas Edward Salk in 1952. The theory behind the Salk Vaccine is that a virus that has been killed cannot infect or multiply, but it can still produce antibodies against that particular virus. The vaccine was tested first on monkeys and eventually on children, including Dr. Safk’s three children, before it was released for nationwide distribution.
• 381 What are Pachyderms? Animals with thick skin like elephants and rhinoceros.
• 382 Why is it that some people have a dark skin? The dark colour of the skin is due to a pigment called melanin. On exposure to sunlight, man’s skin undergoes gradual tanning to protect the skin from injurious solar rays.
• 383 Which Vitamin helps in preventing rickets? Vitamin-D.
• 384 Which is the second most common element on the
• earth’s surface? Silicon.
• 385 Which planet is known as the red planet? Mars.
• 386 What does a lizard do when its life is in danger? The lizard discards its tail to divert the attention of its enemy.
• 387 Why is the housefly considered a health hazard? On their legs they may carry millions of germs. When they rest on a food plate, these may be transferred to the object they rest on.
• 388 Which metal is also called quicksilver? Mercury.
• 389 What is the main food of a Koala bear? Eucalyptus leaves.
• 390 If hair is dead tissue, how does it grow? It is true that hair consists of Keratin, a dead tissue. But the hair is lodged in a follicle located a little below the scalp, which is very much alive. This is where the growth takes place. The living hair pushes up the dead tissue. That living tissue also dies and is pushed up. Pull out a hair and you will feel pain and understand the truth of this statement.
• 391 What is meant by Acid Rain? When there is a substantial amount of sulphur dioxide, carbon dioxide, etc in the rain, it is referrec to as acid rain.
• 392 What is the common food of the Blue Whale? A shrimp like creature called krill.
• 393 What is Betelgeuse? It is one of the brightest stars visible in the night sky, It is in the constellation, Orion. It is also called Alpha Orionis, It takes about 300 years for the light from Betelgeuse to reach the earth.
• 394 How long do elephants live? 65 to 100 years.
• 395 What do a koala bear, opossum, wombat and bandicoot have in common? They are all Marsupials, i.e. they carry their young ones in pouches.
• 396 Name the person who first discovered the presence of Microbes. Anton Van Leeuwenhoek.
• 397 How do mother animals recognize their babies? By their smell.
• 398 Why do water pipes burst in hill stations? There is an unusual expansion of water, when its temperature goes below 4° C. Instead of contracting, the water begins to expand till ice is formed at zero degrees Celsius. Unable to bear the pressure, the pipe bursts.
• 399 Which animal shoots its quill and hurts the enemy? Porcupine.
• 400 Who made the first electric motor? Michael Faraday.
• 401 Who first used electrolysis for isolating elements? Sir Humphry Davy.
• 402 Who first put forward the Atomic Theory that all matter is made of atoms, held together by some force of attraction? John Dalton.
• 403 Is it true that the age of a tree can be known by studying its rings? Yes, each year during spring a light ring grows just inside the bark of the tree. During summer and autumn, the ring that grows is darker. Too little sunlight, too little moisture or injury results in a smaller and darker ring. After counting the rings, we can assess the age of the tree.
• 404 How does the rotation and revolution of the earth affect our lives? The earth rotates on its axis even while it revolves around the sun. The rotation results in night and day. As the earth revolves around the sun, it also tilts on its axis. This tilt causes changes in the earth’s position, which results in the seasons.
• 405 Who found out that oxygen is present in both water and air? Antoine Lavoisier.
• 406 Which Vitamin is important for the health of bones? Vitamin D.
• 407 Why do animals like rats and squirrels keep gnawing at things? Gnawing helps wear down their teeth. If they did not gnaw at things their teeth would keep on growing.
• 408 Who was the first woman of Indian origin to travel in a space vehicle? Kalpana Chawla.
• 409 Why does a snake flick its tongue so often? To smell the surroundings.
• 410 What is the scientific name for man? Homo Sapien.
• 411 Who is considered to be the father of modern experimental science? Galileo Galilei.
• 412 What is the name of our galaxy? Milky Way.
• 413 How is petroleum formed? Remains of plants and tiny animals that lived millions of years ago remain buried and turn into petroleum.
• 414 What is a mirage? How is it caused? A mirage is a reflection, caused by the bending of light rays. When we ride along highways particularly in arid regions, we see a reflection ahead, which looks like water. This is caused by a dense layer of warm air near the surface of the earth. Light rays from the sky are reflected toward one’s line of vision – what one sees is a reflection of the sky and not water.
• 415 How is oxygen formed in the atmosphere? In the presence of chlorophyll, a chemical reaction takes place in the leaves using carbon dioxide in the air and water transported from the roots. As a result of the chemical reaction, starch is produced. Oxygen is the by-product of this reaction.
• 416 Which is the juice secreted in die liver which helps digestion? Bile.
• 417 What is meant by the word ‘frequency’ of a sound? Frequency is defined as the number of vibrations per second. It must be noted that sound is caused as a result of vibrations in air columns or strings or objects. Sound travels in waves.
• 418 Which is the longest poisonous snake in die world? King Cobra
• 419 What is the tendency of plants to grow towards sunlight called? Phototropism.
• 420 Why do snakes shed their skin? Unlike human beings, whose growth stops around 20 years, snakes keep on growing. This becomes possible because they keep casting off old skin and develop new skin, when the old one is shed.
• 421 Why does it take longer to cook food at high altitudes? The atmospheric pressure at high altitudes is much lower than at sea level. The greater the pressure, the faster the cooking.
• 422 What is the use of the ozone layer in the earth’s atmosphere? It bounces off ultraviolet radiation.
• 423 How do we get heat and light from the sun? Through radiation.
• 424 How do insects breathe? Insects breathe through the tiny holes in their body.
• 425 Why doesn’t ice sink in water? Ice is lighter than water. After the temperature of water cools down to 4° Celsius (instead of contracting) water keeps on expanding till it reaches 0° Celsius and becomes ice.
• 426 Apart from earth on which other planet in the solar system does life exist? Nowhere else. As we know it.
• 427 What is meant by the Water Table? Water filters down the surface of the ground and is absorbed and stored by soil and rocks in a zone of saturation. The top of this zone is called Water Table. During drought, the Water Table too goes down.
• 428 Who is known as the father of computers? Charles Babbage.
• 429 Why do we feel hungrier in winter? In winter we need energy to maintain the body temperature in addition to sustaining normal activities of the body. To meet this requirement of energy we eat more.
• 430 Can you give ah example of reflex action? Knee jerk. It is the involuntary kick caused by a blow on the tendon just below the knee.
• 431 What is an electrocardiograph? The electrocardiograph is an electrical instrument, which records the activity of the heart muscle. As the heart beats, several activities take place in a regular! order. The electrocardiograph records changes that occur in a regular order, during a complete heartbeat.
• 432 Which bird can rotate its head by 180 degrees on either side? The Owl.
• 433 Man, dogs, cats, horses have lungs through which they breathe. How do smaller animals like fish, earthworm, etc obtain their requirement of oxygen? Earthworms also respire. They use their moist skin to exchange carbon dioxide for oxygen. The fishes use their gills to respire. Even frogs in the tadpole stage use their skin for respiring. Reptiles such as snakes and turtles and even birds breathe through lungs.
• 434 What are the uses of snake venom? It is helpful in curing many ailments affecting the nervous system.
• 435 What is the major element a star is made of? Hydrogen
• 436 Where does a female butterfly lay its eggs? Under side of leaves.
• 437 Who invented the miner’s safety camp? Sir Humphry Davy.
• 438 Name the world’s largest rodent and where is it found. Capybara found in the Amazon jungles of South America.
• 439 What is the chemical name of baking soda? Sodium Bicarbonate.
• 440 What is Telepathy? Telepathy is direct communication of thought from one person to another, without using any physical channels of communication. Though there are many who claim telepathy is possible, there has been no positive proof of the existence of telepathy.
• 441 What is ultrasound? Human beings cannot hear sound waves which have frequencies above 20,000 vibrations per second. This is termed ultrasound.
• 442 Who was the scientist who initiated the Atomic Energy Programme of India? Homi Bhabha.
• 443 Who invented the rigid airship? Ferdinand Von Zeppelin.
• 444 Who invented the calculator? Blaise Pascal.
• 445 From which element was the first Atom Bomb made? Uranium 235.
• 446 Who invented the diesel engine? Rudolf Diesel.
• 447 Who made the first locomotive that had successful
• runs? George Stephenson.
• 448 What is paper made of? Mainly wood pulp.
• 449 Name the Chinese method of curing ailments by using needles? Acupuncture.
• 450 What causes rusting? How can it be prevented? Metals like iron are often exposed to moisture. Rusting is the process of oxidation occurring when the iron and air slowly combine to form iron oxides. Oil is often used to slow down rusting. When a coat of paint or varnish is given to a metal, this also prevents (reduces) oxidation.