by admin on Monday, May 7, 2012 5:28 under Interesting Facts.
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- Animals have different ways of escaping predators – most mammals run away, while birds take to the air.
- Some animals use camouflage to hide. Many small animals hide in burrows.
- Turtles and tortoises hide inside their hard shells.
- Armadillos curl up inside their bendy body Armour
- The spiky-skinned armadillo lizard of South Africa curls up and stuffs its tail in its mouth.
- Hedgehogs, porcupines and echidnas are protected by sharp quills (spines).
- Skunks and the stinkpot turtle give off foul smells when they are threatened.
- Meerkats stand on their hind legs and give a shrill call to alert other meerkats to danger.
- The plover, a type of bird, pretends to be injured in order to lure hunters away from its young.
- Many animals defend themselves by frightening their enemies. Some, such as peacock butterflies, flash big eye-markings. Others, such as porcupine fish and great horned owls, blow themselves up much bigger.
- Other animals send out warning signals. Kangaroo rats and rabbits thump their feet. Birds shriek.
- The nine-banded armadillo is one of 20 species of armadillo. Armor plating protects it against all but the most determined of predator.
- The hognosed snake rolls over and plays dead to escape predators. It even smells dead
by admin on Thursday, May 3, 2012 4:45 under Interesting Facts.
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- The human brain is made up of over 100 billion nerve cells called neurons.
- Each neuron is connected to as many as 25,000 other neurons — so the brain has trillions and trillions of different pathways for nerve signals.
- Girls’ brains weigh 2.5% of their body weight, on average, while boys’ brains weigh 2%.
- About 0.85 litres of blood shoots through your brain every minute. The brain may be as little as 2% of your body weight, but it demands 12 — 15% of your blood supply.
- An elephant’s brain weighs four times as much as the human brain. Some apes, monkeys and dolphins are quite near our brain—body ratio.
- The cerebral cortex is the outside of the brain. If laid out flat, it would cover a bed.
- The left hemisphere (half) of the upper part of the brain is more dominant in speech, writing and general language, the right half in pictures and ideas.
- Conscious thoughts and actions happen in the cerebral cortex.
- A human brain has a cerebral cortex four times as big as a chimpanzee, about 20 times as big as a monkey’s, and about 300 times as big as a rat’s.
- Unconscious, automatic activities like breathing, hunger and sleep are controlled by structures such as the brain stem and the hypothalamus.
- Some scientists claim that we humans are the only living things that are self conscious, meaning that we alone are actually aware that we are thinking.
- No one knows how consciousness works – it is one of science’s last great mysteries.
- Most of your thoughts seem to take place in the cerebrum (at the top of your brain), and different kinds of thought are linked to different areas, called association areas.
- Each half of the cerebrum has four rounded ends called lobes – two at the front, called frontal and temporal lobes, and two at the back, called occipital and parietal lobes.
- The frontal lobe is linked to your personality and it is where you have your bright ideas.
- The temporal lobe enables you to hear and understand what people are saying to you.
- The occipital lobe is where you work out what your eyes see.
- The left half of the brain (left hemisphere) controls the right side of the body. The right half (right hemisphere) controls the left side. tile half of the brain is always dominant (in charge). Usually, the left brain is dominant, which is why 90% of people are right-handed. Ihe parietal lobe is where you register touch, heat and cold, and pain.
by admin on Wednesday, May 2, 2012 4:34 under Interesting Facts.
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- Eighty-two percent of the population of North America is descendants of immigrants from Europe.
- Among the smaller groups 13 percent are black, 3 percent Asian and one percent are American Indians.
- Hispanics are descended from a mix of white, black and American Indian people from Spanish-speaking countries of Latin America such as Mexico, Puerto Rico and Cuba. 12 percent of the US population is Hispanic.
- 92 percent of the population of the USA was born there. Many new immigrants are Hispanic.
- The original peoples of North America were the American Indians who were living here for thousands of years before Europeans arrived.
- The native people of America were called Indians by the explorer Christopher Columbus, but they have no collective name for themselves. Most American Indians prefer to be identified by tribe.
- There are about 540 tribes in the USA. The largest are the Cherokee, Navajo, Chippewa, Sioux and Choctaw
- Most black Americans are descendants of Africans brought here as slaves from 1600 to 1860.
- Most European immigrants before 1820 were from Britain, so the main language is English.
- Spanish is spoken by many Americans and French is spoken by 24 percent of Canadians.
- A Sioux chief. Many Sioux Indians were killed by US cavalry in the massacre at Wounded Knee in 1890.
by admin on Thursday, April 26, 2012 15:56 under Interesting Facts.
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- The great white pelican catches about 1.2 kg of fish a day in its large throat pouch.
- The brown pelican dives from a height of 15 m above the water to catch fish below the surface.
- Great white pelican breeding colonies may number as many as 30,000 pairs of birds.
- There are seven species of pelican. Most live and feed around fresh water, but the brown pelican is a seabird.
- Pelicans are often found in large colonies, particularly during the breeding season.
- A great white pelican comes in to land on the water.
- One of the largest pelicans is the Australian pelican, which is up to 180 cm long and weighs about 15 kg.
- The white pelican lays 1-2 eggs in a nest mound on the ground. Both parents help to incubate the eggs and care for the young.
- Pelican chicks are able to stand at 3 weeks old and can fly at 7-10 weeks old.
- In heraldry, a pelican is shown pecking its breast to feed its young on its blood. This may stem from the bird’s habit of resting its beak on its breast.
- White pelicans work as a group to herd fish into a shoal by swimming around them in a horseshoe formation. Then they scoop up pouchfuls of fish with their large beaks.
- In flight, a pelican flaps its wings 1.3 times a second. This is one of the slowest wingbeat speeds, when actively flying, of any bird.
by admin on Thursday, April 26, 2012 3:50 under Interesting Facts.
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- Elasticity is the ability of a solid material to return to its original shape after it has been misshapen.
- A force that misshapes material is called a stress.
- All solids are slightly elastic but some are very elastic, for example rubber, thin steel and young skin.
- Solids return to their original shape after the stress stops, as long as the stress is less than their elastic limit.
- Strain is how much a solid is stretched or squeezed when under stress, namely how much longer it grows.
- The amount a solid stretches under a force — the ratio of stress to strain — is called the elastic modulus, or Young’s modulus.
- A bungee jumper stretches a piece of elasticized rope to a great extent. The rope then returns to its original length pulling the jumper back in the air. The greater the stress, the greater the strain. This is called Hooke’s law, after Robert Hooke (1635-1703).
- Solids with a low elastic modulus, such as rubber, are stretchier than ones with a high modulus, such as steel.
- Steel can be only stretched by 1% before it reaches its elastic limit. If the steel is coiled into a spring, this 1% can allow a huge amount of stretching and squeezing.
- Some types of rubber can be stretched 1000 times beyond its original length before it reaches its elastic limit.
by admin on Monday, April 23, 2012 3:21 under Interesting Facts.
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- Dicotyledons are one of two basic classes of flowering plant. The other class is monocotyledons.
- Dicotyledons are also known as dicots or Magnoliopsida.
- Dicots are plants that sprout two leaves from their seeds.
- There are about 175,000 dicots – over three-quarters of all flowering plants.
- Dicots include most garden plants, shrubs and trees as well as flowers such as magnolias, roses, geraniums and hollyhocks.
- Dicots grow slowly and at least 50% have woody stems.
- The flowers of dicots have sets of four or five petals.
- Most dicots have branching stems and a single main root called a taproot.
- The leaves of dicots usually have a network of veins rather than parallel veins.
- Dicots usually have a layer of ever-growing cells near the outside of the stem called the cambium.
- A dicot begins its life as a pair of leaves growing.
by admin on Saturday, April 21, 2012 15:14 under Interesting Facts.
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- A cortex is the outer layer of any organ, such as the brain or the kidney.
- The brain’s cortex is also known as the cerebral cortex. It is a layer of interconnected nerve cells around the outside of the brain, called ‘grey matter’.
- The cerebral cortex is where many signals from the senses are registered in the brain.
- The visual cortex is around the lower back of the brain. It is the place where all the things you sec are registered in the brain.
- The somatosensory cortex is a band running over the top of the brain like a headband. This where a touch on any part of the body is registered.
- The motor cortex is a band just in front of the sensory cortex. It sends out signals to body muscles to move.
- The more nerve endings there are in a particular part of the body, the more of the sensory cortex it occupies.
- The lips and face take up a huge proportion of the sensory cortex.
- The hands take up almost as much of the sensory cortex as the face.
by admin on Friday, April 20, 2012 15:06 under Interesting Facts.
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- St Petersburg was founded in 1703 by Tsar Peter the Great to be his capital instead of Moscow. In 1914 it was renamed Petrograd.
- Leningrad was dubbed ‘Hero City’ for its desperate defense against the Nazis from 1941 to 1944.
- Moscow is the largest city in the Russian Federation and capital of Russia.
- Moscow is Russia’s main industrial centre, with huge textile and car-making plants, like the Likhachyov works.
- Moscow’s biggest shop is Detsky Mir (Children’s World).
- Moscow’s historic centre is Red Square and the Kremlin, the walled city-within-a-city.
- In the past Moscow had wooden buildings and was often burnt down, most famously by Napoleon’s troops in 1812.
- Moscow is snow-covered from November to April each year, but snow-ploughs keep all the main roads clear.
- St Petersburg is Russia’s second largest city.
- The Cathedral of St Basil is in Red Square and is made up of eight chapels, each one capped by a unique onion dome.
- St Petersburg is an elegant city with many beautiful houses and palaces such as the famous Hermitage museum.
- After the 1917 Russian Revolution, communists renamed the city Leningrad and made Moscow the capital. St Petersburg regained its name in 1991.
by admin on Thursday, April 19, 2012 14:57 under Interesting Facts.
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- The ribs are the thin, flattish bones that curve around your chest.
- Together, the rib bones make up the rib cage.
- The rib cage protects the backbone and breastbone, as well as your vital organs – heart, lungs, liver, kidneys, stomach, spleen and so on.
- You have 12 pairs of ribs altogether.
- Seven pairs are called true ribs. Each rib is attached to the breastbone in front and curves around to join on to one of the vertebrae that make up the backbone via a strip of costal cartilage.
- There are three pairs of false ribs. These are attached to vertebrae but are not linked to the breastbone. Instead, each rib is attached to the rib above it by cartilage.
- There are two pairs of floating ribs. These are attached only to the vertebrae of the backbone.
- The gaps between the ribs are called intercostal spaces, and they contain thin sheets of muscle which expand and relax the chest during breathing.
- Flail chest is when many ribs are broken (often in a car accident) and the lungs heave the chest in and out.
by admin on Wednesday, April 18, 2012 14:45 under Interesting Facts.
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- Waves in the sea are formed when wind blows across the sea and whips the surface into ripples.
- Water particles are dragged a short way by the friction between air and water, which is known as wind stress.
- If the wind continues to blow long and strong enough in the same direction, moving particles may build up into a ridge of water. At first this is a ripple, then a wave.
- Waves seem to move but the water in them stays in the same place, rolling around like rollers on a conveyor belt.
- The size of a wave depends on the strength of the wind and how far it blows over the water (the fetch). If the fetch is short, the waves may simply be a chaotic, choppy ‘sea’. If the fetch is long, they may develop into a series of rolling waves called a swell.
- One in 300,000 waves is four times bigger than the rest.
- The biggest waves occur south of South Africa.
- When waves move into shallow water, the rolling of the water is impeded by the sea-bed. The water piles up, then spills over in a breaker.
- A wave over 40 m high was recorded by the USS Ramapo in the Pacific in 1933.
