Discovery of Facts

  Skin, Nose and Tongue How do we taste things?   Taste buds are sensory organs that are found on your tongue and allow you to experience tastes that are sweet, salty, sour and bitter. Other senses are also used along with the taste buds. The taste buds can only detect the difference between sweet, salty, sour and bitter. But when you eat, other sensations heat and cold, texture and especially smell-also help. It is these extra sensations which help to tell the difference between different foods. Taste buds The taste buds contain clusters of cells with hairs on the end. They allow different tastes to be recognized. Cheese tastes The taste buds can hardly differentiate between these pieces of cheese. But the sense of smell combines with taste to reveal the flavor. What are taste buds? Taste buds are Clusters of special cells set in tiny wells in the tongue. They are so tiny that there are 10,000 of them altogether. As you chew, tiny particles of food dissolve ...

  Dressings When did people first wear? NO ONE KNOWS EXACTLY WHEN people started wearing clothes. But the first clothes were probably animal skins. People wrapped them around themselves to keep themselves warm. It was only when people began to farm an settle in the villages that the earliest real clothes were worn. first, these were just skirts and shawls made from twisted tufts of wool and flax. Later, people learned to spin and weave cloth.   They also sewed it to make clothes . Clothes People nowadays hardly wear distinctive traditional clothes. They prefer to wear the shirts, trousers, skirts and jackets made popular in Europe and North America . Who were the first fashion victims? The women of Ancient Summer Wore beautiful colored clothes along With fancy head-dresses 5,000 years ago. They also adorned gold and silver earrings and necklaces, studded with jewels such as lapins-lazily and carnelian. Who first wore cosmetics? If may have been the women of A...

  Remains What are fossils? Fossils are the preserved remnants of plants and animals. They are usually found in rocks. They are several years old. They may be the remains of living things like bones, shells, eggs, seeds and so on. Or, they may footprint or scratch marks left long ago. Different fossils There are different ways in which things once alive can be fossilized. What are stromatolites? The oldest fossils are 'Stromatolites'. They are formed by bacteria such as cyanobacteria. Some of these date back to over 3 billion years! How does formation of fossil take place? Most fossils form when the dead remains of animals or plants get buried in the mud. They remain buried for years and eventually turn to stone. How can a fossil's age be found? Scientists fell a fossil's age from the rock it is found in. They know how Ola rocks are relative to each other because layers of rock form on top of each other, so the lowest layers are the oldest. Measuring...

  Ear and Hear SOUND WAVES TRAVEL THROUGH THE AIR and are picked up by your ears. Your ear flap funnels sounds through a tube called the ear canal. The sound reaches the eardrum. It vibrates the eardrum. As the eardrum vibrates, it rattles three little bones called ossicles. They knock against the 'cochlea' deep inside the ear. The cochlea is filled with fluid, and as it is knocked, waves run through the fluid. The waves waggle the hairs attached to nerves. The waggling of the hairs tells   your brain about the sound. Inside the ear The flap of the skin on the side of your head is only the entrance to the real ear. Inside are all the complex mechanisms of the middle ear, designed to pick up the faintest vibrations in the air and amplify them enough for the hearing nerve to respond to. Why have you got two ears? You have two ears so that you can tell which direction a sound is coming from, You Can pinpoint sound because a Sound to the left of you is slightly lou...

  Skeleton Why do we have bones in our body ? THE BONES FORMTHE STRONG, rigid framework called the skeleton. It supports the body. Not only is it an anchor for your muscles, but it supports your skin and other tissues also. It also provides protection to your heart, brain and other organs. Without the bones, you would flop on the foor like a jelly. How many bones do you have ? A baby's skeleton has oveer 300 bones, but some fuse fogether as it grows. An adult has 206 bonesthough some people have extra bones in their back. What is inside a bone? In the centre of bones isa thick Soft, jelly-like material called the bone marrow. This makes blood cells like red blood cells and white blood cells . Why are bones strong? The fough outer casing of the bones is a combination of two things one that makes them flexible and the ofher which makes them stiff. The flexible material is collagen in the form of strong, stretchy strands. The stiff material is made of hard deposifs of ...

Eye and vision Our eyes resemble a TV camera. At the front is a lens called the cornea the disc in the centre of your eye. This projects a picture onto an array of light-sensitive cells.hias area Is called the retina which lines the back of your eye. The retsa then sends signals to your brain . Why have we got two eyes? Each eye gives a slightly different view of the same thing. The near era thing is, the greater the difference between the view. These slight differences combine in the brain to give us an impression of 3D depth and solidity, and allow you to judge easily just how far away things are. Eyes Your eyes eyes are two tough little balls filled with a jelly-like substance. They are very sensitive to dirt, so you blink frequently to wipe away the dust, and they are washed away by tears. How do you see when it is dark? In order to see well in the dark, your pupils open wider to let in more light. In the dark, it gets up to 16 times bigger. The sensitivity of the ret...

  Respiration Why do we breathe? The cells in your body need a continuous supply of oxygen to burn up the food in the blood. They get their oxygen from the air you breathe in. Without oxygen, your body cells dieand the brain cells die the quickest of all. If you stopped breathing for very long, you would soon lose consciousness. Your brain would be damaged and ultimately you would die. What do you breathe out? You breathe out fhe air you breathe in, minus a little less Oxygen. But if also contains a little waste carbon dioxide brought to the lungs from your body cells in the blood. How does oxygen get to each cell of the body? Made up of the heart, blood and blood vessels, the circulatory system is your body's delivery system. With each heartbeat, blood is sent throughout our bodies, Carrying Oxygen and nutrients to all of our cells. A Blood vessels Arteries rich in oxygen carry bright red blood. Veins which return carbon dioxide to the lungs are bluer. How does y...

  Food Why do you eat? Most of the food you eat is fuel which is burned by your body to get energy to keep you going. To get energy, you need carbohydrates and fats. You also need small amounts of proteins for repairing and building body cells. Tiny traces of vitamins and minerals are also needed . Where does food go when youeat it? The food goes down your body through a long tube called the alimentary canal. When you swallow the food, it slides down your gullet or esophagus into the stomach. Here, it churns around for a few hours. Then, if is squeezed into along, cold fube called the small intestine. The nourishing parts of the food are absorbed into the blood here. The rest are passed on into a larger tube called the large intestine. The waste or feces is pushed out through the anus. How long are your guts? The guts or intestine are coiled up so much that if you unwound them, they would be over three times as long as your body-6 m.   Digestive system If you c...