Science-5

Science-5

No. Question Answer 601 Name the first aircraft to hard land on the moon. Luna 2. It was launched on September 12, 1959 by the USSR. 602 Name two countries, which use geothermal heat (heat from far below the earth's surface) to produce electricity? Italy, Iceland, Japan, New Zealand, USA and Russia. 603 What is cerebrum? The cerebrum is the main part of the brain and controls the ability to think. The cerebrum receives impulses and directs the body into activity. 604 What are citrus fruits? Citrus fruits are those, which contain citric acid in sizeable amounts. Citric acid gives the citrus fruits their sour taste. Lemons, oranges and limes all contain citric acid. 605 What is the difference between an Arabian camel and a Bactrian camel? The Arabian camel (or dromedary) has only one hump, while the Bactrian camel has two humps. 606 What is carbolic acid? The scientific name for carbolic acid is Phenol. It is extremely poisonous. It is used in the preparation of some plastics. Picric Acid, obtained from phenol, is an ingredient in many explosives. 607 What is meant by a Marsupial? Animals carrying their young ones in a pouch. 608 What is the only food of the giant pandas in the wild? Bamboo shoots and leaves. 609 What is the name for the unit of electric power? Watt. 610 What causes tides in the ocean and sea? Gravitational pull of the moon and to some extent the sun. 611 Why does a fire look yellowish, at times? When the combustion (burning) is not complete the colour of fire becomes yellowish. When the combustion is complete, the colour changes to pale blue. 612 Which material is used to make cellophane? Cellulose, the chemical substance that lines the walls of plant cells. Cellophane is used in packaging. 613 What is a cataract? Cataract is a disease affecting the lens of the eye. The lens consists of a semi-solid substance, enclosed in a capsule. Cataract is a condition in which the lens loses its transparency and tends to become opaque. 614 What is the difference between mass and weight? Weight and mass are two different things. The amount of matter that a body contains is mass whereas the weight of an object will be a little less near the equator (where it is further away from the centre of the earth) and a little more at the poles. An object in free space has no weight, but it will have a definite mass. 615 What is meant by a catalyst? A catalyst is a substance, which alters the rate of speed of a chemical reaction, without itself being permanently changed. Normally a catalyst hastens or encourages the rate of reaction. However, at times, catalysts are used to slow down a reaction. 616 Who discovered Penicillin? Alexander Fleming 617 What is measured in the Richter scale? Earthquakes. 618 When was the metric system introduced? During the French revolution, France introduced the metric system. The standard of length was related to the dimensions of the earth rather than the dimensions of a human limb. 619 Where would you find a dodo? Nowhere. It was last reported in Mauritius in 1681. Now it is extinct. 620 When did Marie Curie win the Nobel Prize? In 1903 for physics and in 1911 for chemistry. 621 Of all the bones in the skull and the face, which is the only movable bone in human beings? The lower jaw. 622 How big is the Milky Way? It is estimated that the Milky Way has over a hundred billion stars. The sun is one of the stars in the Milky Way. 623 Where does the impure blood enter the human heart? It enters the cavity of the right auricle through two veins - one called the superior vena cava enters from the head region and die other called the inferior vena cava enters from the lower or posterior region of the body. 624 What is the difference between Direct Current and Alternating Current? The current flowing in a circuit is described as direct current if it flows continuously in a single direction, and as alternating current if it flows alternately in each direction. 625 What is distillation? Distillation is the process of converting a liquid into vapour form (by heating) and then cooling this vapour to recover the evaporated constituents by the process of condensation. 626 How does a thermos flask retain die heat of its contents? It has a tightly fitting cap of cork or such material, which is a poor conductor of heat. The bottle has a double layer of glass. Glass too is a poor conductor. There is vacuum between the layers of glass to prevent loss of heat by convection and conduction. If the surfaces are made highly reflective, even radiation can be reduced. 627 Who made the first balloon that could fly? Joseph & Jacques Montgolfier. 628 How are mosquito fish helpful to man? They eat mosquitoes. 629 What is meant by the Hippocratic oath? Hippocrates was a Greek physician whose oath is still taken by medical students, when they graduate. The oath reads, in part, "I swear so far as power and discernment shall be mine, I'll carry out regimen for the benefit of the sick and will keep them from harm and wrong. To none will I give a deadly drug even if solicited. Into whatsoever house I shall enter I'll go for the benefit of their sick" There is also a clause that secrecy will be maintained about the ailment of the patients. 630 Name the animal, which has the largest eyes in the world. The Atlantic Giant Squid. The diameter of its eye is about 30 cm. 631 What is horticulture? Horticulture is the science and art of growing fruits, vegetables, flowers or ornamental plants. 632 What is a hygrometer? A hygrometer is one of the instruments used to measure the moisture in the air. 633 What is an Ibex? Where are they found? The Ibex is a mountain goat. It was close to extinction in the Alps. It is now under Government protection. In India Ibex is found at high altitudes in Kashmir. 634 What is inertia? Inertia is the property of matter, which keeps a body at rest unless a force is exerted on it. Inertia also keeps a moving body in motion at the same speed and in the same direction unless a force is applied to stop this forward motion. 635 Who discovered the laws of planetary motion? Johannes Kepler - Sir Isaac Newton later used these laws as the basis of his law of Universal Gravitation. 636 What is hybridisation? Hybridisation is the mating or crossing of two parents of different species or varieties. Thus a mule is a hybrid of a horse and an ass. In the case of flowers, hybridisation is done by taking pollen from one plant and dusting it on the pistils of another plant. A bag is placed over the pistils until the seeds are developed. Then the seeds are planted and a hybrid is formed. 637 Who discovered the germ, which causes tuberculosis? Robert Koch, a famous German physician. 638 What is an antidote? A remedy for poisoning is called antidote. The remedy may consist of (a) Neutralising the poison (c) Preventing the body from absorbing it or (d) Assisting the body in eliminating. 639 What is a desert? A desert is a large area of land that is too dry to support life. Deserts are not always hot, dry or sandy. The tundras of Siberia (in Russia) are deserts. Water is frozen here and does not support life. 640 Who invented the dynamo? Michael Faraday. 641 Why is the Egyptian plover bird popularly called the "crocodile bird"? The Egyptian plover bird has been nicknamed the crocodile bird following an account by Herodotus that he saw these birds enter the open jaws of crocodiles and pick pieces of food from their gums. 642 Which were the first passengers to fly in a balloon? A sheep, a cock & a duck. 643 Which was the first living being to enter space? A dog named Laika. 644 What is a light year? In measuring distances on earth we use units like miles and kilometres. But even for giving the distance between the sun and the earth, we have to write 93,000,000 million miles or 150,000,000 kilometres. To write the distance between Alpha Centauri and earth we have to write long numbers. Hence measuring in units based on the speed of light has been adopted. In this scale the sun is 8 minutes from the earth. In kilometres one light year is approximately 924 x 1013 or 9,240,000,000,000,000 kilometres. Alpha Centauri is just 4.6 light years away. 645 Which element is important in the formation of blood? Iron. 646 Name the animal that can lift 50 times its weight. Ant. 647 Which fish carries its eggs in its mouth? Catfish or Cichlid fish. 648 How do fireflies produce light? There are proteins in the body of fireflies that produce light, when they get oxidized in the presence of the enzyme, Luciferase. 649 Where in the world are wooly Mammoths found? They are extinct and are not found anywhere. But about a million years ago, they roamed over land They were the ancestors of modern elephants. 650 In which organ of the human body are the lymphocyte cells (blood cells) manufactured? Spleen 651 What are the constituents of stainless steel? Stainless steel is an alloy of iron, nickel and chromium. Stainless steel making involves the removal of impurities and addition of desirable metals like chromium and nickel. 652 What is meant by the term Water cycle? Water Cycle is the story of a raindrop, which passes through other phases to become a raindrop again. In summer the water in lakes and rivers evaporates. This water vapour is warm and is pushed up by cold air. As the warm air moves upwards air currents develop. They are called winds. When the warm air passes over mountains or when it goes high up, it cools down and condenses to water again and falls down to earth. On the surface of the earth the raindrops may join other raindrops and if the earth cannot absorb this water quickly, they form streams and rivers. And the cycle continues. 653 What is Plaster of Paris? When gypsum is heated to 120° C it loses water and becomes a white powder. That is plaster of parts. When water is added to the powder, it hardens. It is used for plasters, moulds and models. 654 Who discovered Plutonium? Glenn Seaborg. 655 Who was the person to first identify the proton? Ernest Rutherford. 656 What is a planarium? A planarium is a simple form of life, which crawls about and feeds on small animals. 657 Why does milk spill out when boiled? When milk is heated, the water in it starts evaporating. The fat globules present in the milk get separated and float on the top as cream. On further heating, more water vapour is formed. But when it tries to escape, it gets trapped by the thick layer of cream on the top. The water vapour pushes up the layer of cream and forms a bulge, which finally bursts out, causing the spill. 658 What is the difference between a porpoise and a dolphin? Porpoises are smaller than dolphins and they do not have beak like snouts of dolphins. Porpoises live in the shallow water of ocean bays and the mouths of rivers, while dolphins live out in the deeper waters. 659 Where is the pituitary gland situated in the body? In the brain on its underside. 660 What is ozone? Ozone is an isotope of oxygen with three atoms of oxygen in its molecule. 661 What is the difference between a planetarium and a telescope? Through a telescope we can see a real but small part of the sky. On the dome of the planetarium what we see is a picture of the sky, containing the sun, the moon, the stars and planets in an artificial sky. 662 What is meant by the term 'Orbit'? Orbit is the path of any body revolving around another body. This path can be circular or elliptical (as an ellipse). 663 Where do frogs lay their eggs? All frogs go back to water to lay their eggs. 664 Who was Pythagoras? He was a Greek Philosopher and mathematician who lived around 520 BC. 665 Who propounded the theory that the sun and not the earth is the centre of the Solar System? Nicolus Copernicus (Bhaskaracharya of lllh Century A.D and Aryabhata of the fifth century A.D seem to be aware of this). 666 Who invented the lightning rod to help prevent lightning from damaging buildings and physical property? Benjamin Franklin of USA. 667 What is an anableps? Any of the three species of Fish, commonly referred to as four eyed fish. An anableps has the ability to see above and below the water at the same time. 668 Why is it dangerous to walk on quicksand? Quicksand is a bed of very fine, powdery wet sand. It is a thick fluid. Once a foot is placed on quicksand, it is not easy to pull it away. The foot may slowly sink in the quicksand. Struggling to take out the foot may sink the foot further down. It is advisable to wait for help. If a man remains calm and does not move his foot, he may stop sinking. 669 What is an antiseptic? It is a chemical used to kill germs on the skin or in the wounds. It is also used on things people handle. 670 What is a satellite? A body that revolves around another is called a satellite. The earth and the other planets are satellites of the sun. The moon is a satellite of the earth. 671 What is Greenwich Meridian Time? Greenwich Meridian is an imaginary north-south line on the earth's surface drawn through Greenwich near London and both geographical North Pole and South Pole. This line has been arbitrarily chosen as the 0° longitude. 672 Who for the first time in recorded history used a prism to split white light into many colours? Sir Isaac Newton. 673 What is a fuse? The fuse is a strip of metal (or metallic wires) that melts at a relatively low temperature. When an electric circuit carries more electric current than it is supposed to carry, the fuse melts and prevents fires. 674 What is meant by the term 'freezing point'? The temperature at which a liquid changes to the solid state is called freezing point. 675 Who made the first printing press with moveable types? Johannes Gutenberg of Germany in the middle of the | 15* century. 676 What is meant by wireless telegraphy? Wireless Telegraphy originally consisted of a sending key, which opened and closed the circuit and a sounder connected by wires to the key. Whenever the circuit was complete a click sound would be heard. Thus all the letters would be represented by the sounds being produced in the right sequence. 677 Which is the largest flesh-eating animal? Kodiak bear. 678 What is larva? A larva is a young animal that is not fully developed but is able to move about and feed itself. It changes into an adult animal that usually looks different. This change is called metamorphosis. Tadpoles, which grow into frogs, caterpillars, which grow into butterflies, and grubs, which grow to become beetles, are all examples of larva. 679 Is it true that the Himalayas grow taller year after year? Yes, about one mm a year. The solid layer of the earth consists of about a dozen semirigid plates. As the Indian plate moving north presses against the stationary Asian landmass, the height of the Himalayas increases. The increase is imperceptible. 680 Why doesn't a crocodile harm the plover birds that enter its mouth? Because the plover birds enter the mouth of the crocodile and eat tit-bits found there. This helps the crocodiles to improve their oral hygiene. Therefore crocodiles do not harm the plover birds. 681 From where does the moon get its light during the night? Earth 682 How many parts was a day divided into, in ancient India? Eight parts, called prahars. The Hindi word 'dupahar', for noon, is derived from 'du' (two) and pahar (prahar). 683 What was special about the telescope invented by Newton? The telescope devised by Galileo was a refracting telescope. The refracting telescope uses a large convex lens as the objective to focus light and form a real image. Another lens is used to magnify it. The reflecting telescope uses a large parabolic or concave mirror instead of the objective lens to focus light and form a real image. The images produced by these telescopes are inverted. An additional lens is used to right the image. 684 How are we protected from the ultraviolet rays of the sun? Ultraviolet rays come from the sun. If all the ultraviolet rays emanating from the sun travelling to the earth were to reach the earth, all life on earth would be destroyed. But this does not happen, because a layer of ozone (20 to 50 km) above the earth's atmosphere absorbs the ultraviolet rays of the sun. 685 What is the meaning of the word Tanning'? Converting raw animal skin into leather. 686 Who developed the modem concept of the element? Antoine Lavoisier. 687 How do bees communicate? Bees communicate the source of nectar to others by the pattern of the dance they perform. 688 Who invented the Thermos Flask? James Dewar. 689 What were the first words to be recorded on the gramophone made by Edison? "Mary had a little lamb." 690 Which is the hardest substance in the human body? The enamel that covers teeth. 691 What is a bone made up of? Two-thirds of the bone is calcium phosphate. The other one-third is gelatin. 692 What are sweat glands? Sweat glands are located under the skin of mammals. They are coils of soft, tiny tubes. The tube ends at openings in the skin called pores. Sweat glands carry moisture and waste material to the surface of the skin. When the water is brought to the surface of the skin it evaporates there and keeps the body cool. 693 Why can't a horse sit? They don't have knees on their hind legs. 694 What is the lead of a pencil made of? Graphite, whose main constituent is carbon 695 Who discovered radioactivity? A.M. Becquerel. 696 Who produced the first synthetic dye? William Perkin. 697 Where are the lobster's teeth located? In the stomach. 698 What is parachute? How does it work? Parachute is nothing but a big umbrella made of a special fabric. The parachute and the person using it are subject to two forces: - 1) gravity, which brings them down and 2) the buoyant force of air, which pushes up the umbrella. If the force of the gravity is greater than the buoyancy, the parachute moves down, but very slowly. Hence men can reach the ground safely. 699 What is inoculation? ntroduction of germs into a body to precipitate a mild form of a disease. As a result antibodies are produced, which protect the body from the invading germs. 700 What is meant by Acrophobia? Fear of heights. 701 How many lobes does a human liver have? Four 702 What is fog? Fog is water vapour condensing near the surface of the earth. Fog differs from clouds in that fog is close to the earth and clouds are in the sky. 703 What is the unit used for measuring work or energy? Foot-pound. Thus if an object weighing one pound were lifted through a distance of a foot, one footpound of work would be done. 704 How many chambers are there in a human heart? Four. Right auricle, left auricle, right ventricle and left ventricle. 705 What is the blood condition involving an abnormal reduction in the number of red blood cells called? Anaemia 706 How are hereditary characters transmitted from one generation to the next? Genes are believed to be responsible for transmitting hereditary characters. Every human cell contains 23 pairs of chromosomes, which are made up of many paired particles or units called genes. 707 How are hydrocarbons produced? Hydrocarbons consist mainly of hydrogen and carbon. They are produced from the breakdown of plants and other living beings, either by bacteria or by heat and pressure under the surface of the earth. They are also called Natural Gas. 708 What is the human body made up of, according to Hippocrates? Blood, phlegm, yellow bile and black bile. 709 From which plants do we get potatoes? How? Potatoes grow on potato plants. The plant stems grow under the ground and are called tubers. These are the edible parts and are called potatoes. Spanish explorers brought the potato to Europe. 710 What are glacial ages? There have been several periods of time when much of the earth's surface became covered with ice. These different periods of time make up the glacial ages. 711 How many nephrons does a human kidney contain? About a million. 712 What is the common unit of measurement of electric power? Kilowatt Hour. 713 When we run very fast or work strenuously, we feel tired. What is this tiredness due to? Lactic Acid is formed when the glycogen or sugar in the muscles is used. This makes us feel tired. 714 How are gills important to fish? They are used for breathing air by most Fishes and certain other lungless animals. 715 What are radioactive elements? These are elements in which protons and neutrons are not in balance. They slowly breakdown to form stable elements. 716 What are lichens? Lichens are plants that have no flowers, roots, leaves or stems. They grow on rocks and along beaches. They live on the bark of tree on the highest mountains. 717 Whose notebooks were Filled with ideas and sketches of inventions, including designs for an airplane? Leonardo da Vinci. 718 What is a ligament? Ligament is a term for individual tough fibrous bands of connective tissue that support the internal organs and hold bones together at the joints. 719 What is a larynx? The larynx is the voice box, located in the throat. 720 Who is considered as the father of modern rocketry? Robert Mulchings and Goddard Hutchings. 721 What is Brownian movement? That small particles of matter (molecules) are in constant motion was observed by Robert Brown through his microscope, by putting very fine powder in water. This movement of molecules is referred to as Brownian movement. 722 What is camouflage in nature? In nature many animals resort to a number of ways to protect themselves from enemies or predators. This is called camouflage. The Polar Bear, having a white colour is an example of camouflage. Similarly zebra's colour confuses its enemy and serves as a camouflage. 723 What is the chief source of uranium and radium? The mineral, Pitchblende. 724 Why do planes flying at great speeds leave white fumes behind? The planes leaving fume behind are jet planes. In a basic jet engine air is compressed and forced into a chamber, where fuel is added. Here combustion (burning) takes place. The hot gases that are produced escape from the base of the engine. This pushes the aircraft forward. The white fumes that you see are the hot gases as they escape out. Since the temperature around the jet is low, the fume condenses and becomes visible. 725 Why do some people have fat legs? The cause of filaria (elephant leg) are worms called Wuchereia bancrofti the female worm gives birth to young worms and not eggs. These young ones, called microfilaria, find the way into blood stream of their victims and from there into the lymphatic vessels. The immediate cause of filarial is a mosquito called culex. 726 What is a dehumidifier? Why is dehumidification important? Heating, cooling, ventilation and dehumidifying are aspects of air-conditioning. It is believed that a cold climate with a low level of humidity is good for health. Even food is preserved better when the temperature and humidity are low. 727 What is meant by Quarantine? Quarantine is the isolation of persons, animals or plants, which have been exposed to communicable diseases. 728 What is the Pythagoras theorem? The theorem states that the square of the hypotenuse of a right-angled triangle is equal to the sum of the squares of the other two sides. 729 What are pseudopodia? Pseudopodia are temporary extension of the body of a one-celled animal such as amoeba. 730 How is plywood made? Plywood is made by gluing wide thin slices of wood together in order to make a strong board. 731 How many pairs of legs do crabs have? Five pairs. 732 What is a rain gauge? It is a device used for measuring rainfall. 733 How do planaria (flatworm) reproduce? Planaria (plural of planarium) constrict and fragment just behind the pharynx. Both pieces then develop into complete animals. 734 What is a fungus? A fungus is a plant without chlorophyll or true leaves, stem and root. Since they are unable to make their own food, they must live on other living or dead plants and animals. Fungi (plural of fungus) are found almost everywhere. Mushrooms are fungi. 735 What is resonance? When an object is set into vibration with a certain pitch (frequency) any other object nearby that can vibrate at the same pitch, will start vibrating. This is referred to as resonance. 736 Where are the vocal cords located in man? The vocal chords are located in the larynx. The larynx is a hollow muscular organ forming an air passage to the lungs. 737 What are alveoli? The tiny air sacs in the lungs are called alveoli. It is through the walls of the alveoli that the exchange of gases takes place. 738 What is meant by embalming a body? When a body is treated in such a way that it is preserved from decay, it is called embalming. 739 What is embryology? Many animals begin life as a fertilised egg. These grow over a period into the form of an adult animal. The study of the changes that take place as an egg develops into an animal is the science of embryology. 740 What is an element? An element is a substance that cannot be broken down or decomposed into smaller parts by ordinary chemical means. 741 What do elements consist of? Positively charged protons, negatively charged electrons and neutrons, which have no charge. 742 What is electrolysis? Electrolysis is the decomposition of a substance using electricity. For example when table salt is subjected to electrolysis, it turns into sodium and chlorine. 743 Who propounded the theory of relativity? Albert Einstein 744 What is ecology? Ecology is the study of plants and animals in relationship to their environment. Everything that affects plants and animals and how they are dependent upon their surroundings is the subject matter of the study of ecology. 745 Why is an earthworm also called 'a Fanners best friend'? The earthworm is called the farmer's friend because it helps him to keep the soil rich and loose so that plants can grow. As they burrow into soft soil, they swallow some of it, which passes through their bodies and finally is left behind as castings. This is enriched material. 746 What is a mammoth? Mammoth was an ancestor of the elephant (of the modern elephant), which is now extinct. Whole frozen mammoths have been found below the ice in Siberia. 747 What is a manometer? It is an instrument for measuring the pressure of gases. 748 How many satellites does Mars have? Two. 749 What is medulla oblongata? It is the part of brain that connects with the spinal cord. 750 How many pairs of nerves are there in man that are connected to the brain? Twelve pairs. They are called the cranial nerves.