WORLD WAR I
1.What was the cause of World War I?
By the end of 19th century, leading industrial nation Germany had emerged as a posing a threat to France and Britain, Germany formed the triple Alliance with Austria-Hungary and Italy, while Britain, France and Russia formed the Triple entente. Both the groups enlarged their Davies and expanded the armies. The assassination of the Austrian prince, Archduke Franz Ferdinand by a Serbian citizen triggered off the war.
2.Why was it known as ‘The Great War’?
This war involved so many countries that it became popular as “The Great War”. Most of the war was fought from two parallel lines of trenches separated by a short stretch of ‘no-man’s land’. Conditions in the trenches were terrible and disease breeding.
WORLD WAR II
1.When did the World War II begin?
World War II started on September 3, 1939, when Germany, under the leadership of Adolf Hitler invaded Poland.
2.Which of the countries were involved in the war?
The war was fought between the Axis Powers (Germany, Italy and japan) and the allies (Britain, France, United States, Soviet Union). It was mainly fought in Europe; in North Africa and in South-East Asia. By this time, a lot of discoveries and inventions had taken place, which were capable of mass destruction. Now, the aeroplanes were used to drop bombs over the target sections of the countries.
3.HOW aid US get into World War II?
The Japanese attack on the US naval base at Pearl Harbour brought the United States, with its industrial and military might into the war. Before this, many Americans had supported Britain in its fight against European war. Now it was different. Nazi Germany, but had been reluctant to get involved in a The USA used aircraft carriers against Japanese ships, and from captured island bases, sent planes on bombing raids against Japan itself.
4.What is the Significance of Pearl harbour in World War II ?
The US naval base at Pearl Harbour in Hawaii was attacked without warning by the Japanese air force on 7 December, 1941. Four battleships were destroyed, many more damaged and 3,300 people killed. This attack brought the USA into the war on the side of the Allies.
5.What do you know about Nuremberg Trials?
After World War 11, the Allies set up an international military court at Nuremberg in Germany to try the Nazi leaders for war crimes. Twelve were sentenced to death and six were sent to prison. Hermann Goering committed suicide before his sentence could be carried out. Concentration camp commanders were also tried.
6.Who were known as “The Big Three”?
The Allied war leaders Churchill, Roosevelt and Stalin, were knows as – the “Big Three”. They met to plan the defeat of Germany and Japan.
7.When was atom bomb dropped at Hiroshima and Nagasaki?
The Allies planned to invade Japan in late 1945, but feared heavy losses. On 6 August, 1945 an atomic bomb was dropped on the Japanese city of Hiroshima, and three days later a second bomb fell on Nagasaki. The Japanese surrendered, and on 14 August 1945, World War II was over.
1.what was the situation in Germany after the World war?
After the world war Germany was divided between the Allies. The USA Britain and France controlled the west of the country, while the east was controlled by the Soviet controlled territory. The Cold War polarized Germany between the Allies in the West and the Soviets in the East. In 1949, Germany was divided into West and East,
2.What do you know about the Cold War ?
The USA and the Soviet Union emerged from World War II as the world’s dominant superpowers. Former allies, they soon became enemies in what was known as the Cold War.
3.When did the Cold War begin?
The Cold War started when the Soviet Union set up Communist governmen in the countries of Eastern Europe Liberated the Red Army. This effectively divided Europe an “iron curtain’
4.How was nuclear war the cold war?
prevented during to another crisis in 1962, when Cuban dictator Fidel Castro Both sides built up huge stocks of nuclear weapons. This led allowed the Soviet Union to build missile based in Cuba, close to the USA. US President John F Kennedy ordered the
US Navy to blockade Cuba, and eventually, the Soviets agreed to withdraw. To prevent a nuclear war from starting, the missiles were removed. The two sides in the Cold War spent vast sums on weapons. Although they never fought directly, the did get involved in the Korean War in the 1950s and 1970s.
5.HOW was NATO formed?
The North Atlantic Treaty Organization (whose symbol is shown here) was set up on 4 April, 1949, with its headquarters in Brussels, Belgium. It was a military alliance between several Western European countries, Canada and the United States, against aggression from a outside nation. In 1955, the Soviet Union formed an allia of Communist states, the Warsaw Pact.
6.Why was the Berlin Wall built ?
The Berlin Wall was built across the city in 1961 to divide the eastern part from the west, and so preventing people escaping from Communist rule. Berlin Wall
7.Who gave the term “The Iron Curtain” and why?
Europe was divided after World War II into democratic and communist countries. Britain, West Germany, Switzerland, Italy, Spain, France, Denmark, Norway, Netherlands were democratic countries and Soviet Union, East Germany, Poland, Czechoslovakia, Winston Churchill Austria, Hungary, Romania, Yugoslavia, Romania, Bulgaria, Albania, Greece, etc. were communist countries. Winston Churchill gave the name “Iron Curtain” to the boundaries between these democratic and communist countries.
JEWS AND ISRAEL
1.Where did the ancient Jews live?
The Ancient homeland of the Jews was the land around Jerusalem. The Jews were later expelled and by the 20th Russia. The land, now called Palestine, had for many years century most Jews lived elsewhere, in Europe, the USA and led to a long conflict with the people living there. been part of the Ottoman empire. The Jews’ desire to retum
2.Who was known as Lawrence of Arabia ?
TE Lawrence (1888-1935), known as Lawrence of Arabia, was a British soldier who helped to lead an Arab revolt against the Ottoman empire during World War I. After that war, many Arabs hoped to see a new Arab nation, including Palestine. This did not happen.
3.How was Israel formed?
After World War II, many more Jews wameu to move to Palestine. Britain took the matter to the United Nations and in 1947 it was decided to split Palestine into two states, one Jewish and the other Arab. Jerusalem would become international, since it was sacred to Jews, Muslims and Christians. The Jews agreed to this, but the Arabs did not. Britain gave up its mandate on 14 May, 1948 and, on the same day, the Jewish leader David Ben Gurion announced the founding of the state of Israel. The Arab league
CIVIL RIGHTS CRISIS
1.What do you understand by Apartheid?
Apartheid means “apartness”. It was a policy followed in South Africa from 1948 to 1990 to divide the country into separate areas for whites and blacks. There was segregated education, employment, housing and health care. Most whites had good living conditions while the blacks suffered.
2.What civil rights were people fighting for during the later part of 20th century?
During the second half of the 20th century, people all over the world fought for civil rights. They fought for the rights to be treated fairly irrespective of their race, skin colour, religion or gender. People asked for their rights to vote and to form free trade unions.
3.Who was Martin Luther King?
Martin Luther King (1929-1968) was an an American activist, humanitarian and leader in the African-American Civil Rights Movement, His belief in non-violent resistance to oppression, won him the Nobel peace prize n 1964. His most famous speech included he words: “I have a dream”. In 1968, King was shot dead in Jemphis, Tennessee.
1.How did Vietnam become independent from France ?
Vietnam, together with Cambodia and Laos, was part of the French
colony of Indo-China. It was the Viet Minh league, led by the Communist Ho Chi Minh, occupied by the Japanese in World War II. During this time declared Vietnam independent from France.
2.Who was Ho Chi Minh?
Ho Chi Minh (1892-1969) led Vietnam’s struggle for independence from France, As the President of North Vietnam from 1945 he fought for a united Vietnam, which was achieved after his death.
3.What was Guerrilla warfare?
Viet Cong and North Vietnamese soldiers used guerrilla warfare, One tactic was to dig a maze of tunnels. Over 16,000 soldier lived underground, hiding from U.S planes.
1.Why has Middle East been in crisis for So long?
The Middle East has been a world troubleshot since 1948, when an uneasy peace followed the Arab-Israeli war. Israel fought three more wars against its Arab neighbours. Terrorism became a terrible weapon in this conflict, which was bound up with two other issues: the world’s thirst for oil and the rise of Islamic fundamentalism.
2.Who was Ayatullah Khomeini?
Ayatollah Khomeini (1900-1989) was a revolutionary religious leader of Iran. He came to power in 1979 after the Shah of Iran was overthrown. Under Khomeini, Iran became a strict Muslim state.
3.Who was Saddam Hussain?
Saddam Hussein (born 1938) ruled oil- rich Iraq from 1979 to 2003. A brutal dictator, he took his people into three wars: against Iran in 1980-1988, and against US-led forces in 1991 and 2003.
WHICH IS THE LARGEST BIRD?
The largest living bird is the ostrich. This bird can grow to 2.75 m tall and can weigh over 150 kg. It cannot fly but it can run at a speed of more than 60 km/hr, which is faster than a racehorse. An ostrich has only two toes on each foot. The feet resemble those of the grazing antelope and cattle. It has a soft downy plumage, but it has no hair or fur on the head, neck and legs. At 5 cm in diameter, the eyes of the ostrich are the Margest of all birds or of any land animal. It lives in the African savannah grasslands and nests in holes made in Jothe ground. It is the male ostrich which scoops out the hole and leads several females into it to lay their eggs. The egg of the ostrich is the largest and the toughest of all the eggs of the birds. Ostriches produce the strongest commercially available leather in the world and some of the most beautiful feathers.
WHICH BIRD SUCKS BLOOD?
The vampire bat which lives in the rainforests of South Amenco sucks blood. It lives on the blood of other animals such as cattle and horses All bats come out at night When animals are asleep or night, the vampire bat lands on the ground near its victim Then, it walks towards it on all fours. With its dagger-like front teeth, it makes a slit in the skin of its prey. After that, it curls its tongue into a V. shape so that blood may run into it. Sometimes the bai drinks so much blood that it faces difficulty in flying. But the amount of blood lost by the animal is not so much that it is weakened. There is only a danger of infection from the wound. In o single night, a colony of 100 vampire bats can suck blood from 25 Cows or 14,000 chickens. Bats are the only mammals that can fly- There are about 900 species of bats and are found on all the continents except Antarctica
WHICH IS THE LARGEST SEABIRD?
The largest seabird in the albatross. It has a white body ond long, narrow wings which enable it to glide even in still air When it glides near the surface of the sea, it makes use of wind currents from the waves. With the help of these currents it can stay in the air without beating its wings for six hours. Its body is about 1.2 m long. It has o wingspan of 3.7 m, the biggest of any bird, Albatrosses feed on live fish and dead animals which float on the surface of water. They have an excellent sense of smell and can detect rotting carcasses of whales from a distance of 30 km. Since they get their food from the sea, they hardly come ashore. They come to the shore only to breed. The female lays a single large white egg on the ground in the open, which is incubated alternatively by the male and the female bird. The young one takes about 40 weeks to grow sufficiently. Albatrosses live long and are among the few birds that die at an old age. Wild albatrosses live for more than 50 years.
WHICH BIRD STITCHES ITS NEST TOGETHER?
Anest is made by large twigs, small wigs, feathers and all kinds of material including string, plastic and wire. The outer frame is made by the large lwigs with the smaller ones in between to bind it together. The tailorbird is one of the most skilled nest builders. It is usually brightly coloured, with green or grey uppperparts and yellow-white or grey underparts. It often has a chestnut on the head has short rounded wings, a short tail strong legs and a long curved bill. The tail is typically held upright. 11 has a long and thin needle-like beak which it uses to stitch two leaves together to make a pouch for its eggs. It uses the spider’s silk as thread to do this. The nest of the bald eagle is also made out of large twigs and weighs about 1-3 tonnes. The malleefowl’s incubation mounds contain over making it the la Compared to hummingbird’s half tennis ball.
WHICH BIRDS DON’T MAKE NESTS?
atro, The Arctic tem simply scrapes o hollow out of pobles.fokor All birds do not make ness. The firytem boys is egg on the brand of use the abandoned neus of pigeons and crows to lay eggs, The cuckoos ond o few series of ducks have a unique way of rearing their young ones. The female cuckoo lays on egg in the nest of another species the hope that the nest owners will raise the cuckoo chicks as their own. It, then, finds other nests to Joy its eggs in. That of the cuckoo egg hatches carlier than that of the host. II, then, destroys the egg of the host. The cuckoo chick grows quickly, Female parasitic cuckoo seems to specialize and loy eggs that closely resemble the eggs of their chosen host. The foster parents devote all their energy to raising the young cuckoos that grow larger than themselves. Sometimes these cuckoos eat up their foster paren.
WHICH IS THE SMALLEST SEA MAMMAL?
A sea ofter is the smallest sea mammal. It is about 4 feet (1.3 metres) long and weighs about 20-37 kilograms. A sea otter has a small, round head, closeable nostrils, ears with flops and small eyes that are good for seeing in and out of the water. The nostrils and the ears of the sea offer close while it is underwater so that no water moy gel into them. Seo otters have webbed hind feet which they use to swin and their forefeet are smaller. Their claws are semi-retractable. See otters live along the rocky Pacific Ocean coasts, bays and kelp beds They are found from the coast of California to Alaska and from the eastern coast of Russia to northern Japan. They have the thickest fur of oll mammals. Their fur contains two layers – an undercoat and long guard hair on the top. These two layers have air trapped between them to keep them warm. The fur of the sea otier is usually brown or black in colour. They eat crustaceans like crabs), bivalves (like clams, mussels and abalone), octopuses, squids, seo urchins and fish. They hunt for their prey in the ocean and on the sea floor These intelligent mammals use stones to help crack open clams and abalone. ge
WHICH LIZARD HAS A RUFF?
Lords are found in most parts of the world. Most lizards have legs but ypes of lizards are called skinks. Lizards perform several tricks in order to protect themselves from predators. The chameleon can change its colour according to its surrounding. The frilled lizard of Australia and New Guinea runs way on its legs when threatened, has a large ruff around its neck. When it is surrounded by danger, troises its ruff to make itself look bigger. The skin forms a large, colourful, fan-like collar around is head that measures about 30 cm (about 12 inch) in diameter Then, it opens its mouth wide and hisses to make it appear frightening. The bearded lizard also has a ruff. Added to this, it has a collar of scales at the sides of its throat which stand out when the lizard opens its mouth. The frilled lizard measures up to 90 cm (35 in) in length. It can run quickly on its hind legs. It feeds primarily on insects, spiders and small mammals,
WHICH FLIES SPREAD SLEEPING SICKNESS?
Flies are one of the biggest groups of insects. Unlike other insects, all has only one pair of proper wings. Il cannot eat solid food. In order to turn it into a liquid, which it can suck up, it spits a digestive fluid on the food. Mosquitoes, houseflies, midges, black flies, gnats, bluebottles and tsetse flies all are different types of flies. When the tsetses fly, their wings make a noise, which is why they get the name tsetse. These flies spread a disease called sleeping sickness. If not treated the victim may go into coma and eventually die. The tsetse fly looks similar to the housefly Instead of laying eggs like the housefly, the tsetse fly gives birth to grubs. It gives birth to just one baby at a time. The tsetse fly lives on the blood of animals and is found only in Africa. It may grow up to 1.5 cm/0.6 in long. There are 22 species of tsetse flies in sub-Saharan Africa. When houseflies and bluebottles lay their eggs on waste matter, they gather germs which be carried to may the food. If this food is eaten by humans, bacteria enter their may bodies.
WHICH WORMS ABSORB FOOD THROUGH THEIR SKINS?
Worms are long, wriggling, tube- like animals. There are three main groups of worms – the ringed worms, the flatworms and the roundworms. Ringed worms include earthworms, marine worms and leeches. The body of an earthworm consists of a series of rings or segments. Flatworms are worms with Hattened bodies. They include threadworms, hookworms and roundworms. Some flatworms are parasitic, which means that they live inside the bodies of other creatures including humans. Tapeworms are the worst parasitic flatworms. A tapeworm may enter a human body in the form of an egg. The egg hatches inside the stomach. It absorbs its food through NATURAL WORLD the skin as its has no digestive organs. It grows very long and multiplies rapidly. It can be 10m long inside the human body. A human being may get a tapeworm by eating pork or beef, which is not cooked properly.
WHICH SEA CREATURES ARE IN DANGER?
The seo is a vital source of food for humans. But excessive fishing and increasing pollution are cousing the decrease in fishstock very rapidly. For example, whales are hunted as a source of meat. Besides meat, it is hunted for oil. A whale has o blubber la fibrous fissue filled with oil) to keep it warm. In some cases, it can be as thick as 40 50cm The oil extracted is used to make soaps and margarine Besides this, the bones of the whole are ground to be used as fertilizers. Whales are now in danger of being completely wiped out. Both manatees and their relative dugongs are in danger. It is believed that they could be completely extinct by the year 2020. Stellar’s sea cow, a dugong, used to live on the islands of the Bering Sea. During the 18″ century, sailors on expeditions to North America used to spend their winters on these islands. For the purpose of their food, they used to kill the sea cows. As a result, sed cows became extinct within thirty years.
WHICH ARE THE EDIBLE ROOTS?
The roots of some plants get swollen with stored food which can be had as vegetables. The plants which provide such roots are called root crops. Root crops are nutritious staple foods that provide us with carbohydrates – the energy foods that keep us going; some roof crops are spices that add flavour to our food. All root crops have a large water-content and grow best in deeply cultivated soil in cool, overcast weather when the loss of water in a plant through transpiration is lowest. For example, the roots of beet are eaten mainly in cooked form. Beet powder is utilized as a red colouring agent in sauces. Carrots are bright orange-coloured roots. They consist of a high percentage of carotene. Radishes are roots with a strong flavour. White or red roots are usually consumed as appetizers and are also used in salads. Turnip is another root which is eaten. The edible part of the sweet potato is the tuber which can be boiled, fried and steamed
WHICH IS THE TALLEST TREE IN THE WORLD?
California, USA The Coastal Redwood are the talles in the world. They can reach height of about 90 metres or more and their trunks can reach diameters of 3 to 6 metres. The tallest living tree stands at 112 metres (367 teet, 6 in) or five storen higher than the Statue of Liberty. It is a Mendocino Tree, a coast redwood (Sequoia sempervirens) found at Monigomery State Reserve near Ukiah, California, USA. It is estimated to be over 1,000 years old. The tree was last measured in September 1998, and was also found to have a diameter of 3.14 m. The reciwood trees toke about 400 to 500 years to mature and some trees are known to be 1,500 years old. These giant trees grow from tiny seeds that are less than 2 mm long. These trees have very few branches and leaves and are often scarred by fire and lightning marks. As they grow older, the lower branches fall of leaving clear columnar trunks. The Lindsey Greek Tree, a massive redwood, was one of the biggest trees ever known. It blew over in 1905 and it weighed over 3,300 tonnes
WHICH IS THE BIGGEST FLOWER?
The world’s largest flower is the Rafflesia, which grows in the jungles of Sumatra and Java. Its scientific name is Rafflesia arnoldi, after Sir John Raffles and Dr. Arnoldi, the British botanists who discovered the plant in 1818. This flower has orange- brown and white petals and reaches a diameter of about 1 metre and can be 2 cm thick. It can weigh upto 11 kg. Rafflesia is a parasite which has no leaves, roots or stems. Hence, it does not photosyn- thesize. It is usually found in the rainforests of South-East Asia. This flower is popularly called the 2 stinking corpse lily, because it looks and smells just like a huge lump of roting flesh. It attracts thousands of flies which pollinate the flower. Rafflesia individuals grow as thread- like strands of tissue completely embedded within and in intimate contad with surrounding host cells from which nutrients and water are obtained
WHICH IS THE OLDEST KIND OF PLANT ON THE EARTH?
Fems are among the oldest kind of plants that live on land. They belong to a group of plants called feather plants. Scientists believe that ferns appeared on the Earth more than 400 million years ago Most ferns grow on the ground in the damp, shady places, but some are found on the leaves or stems of other plants. There are about 10,000 species of terns found all around the world. Fern leaves are called fronds. Ferns grow into new plants not from seeds but from spores in two stages. First spores are made in sacs called sporangia , These are the brown spots on the underside of the fronds. These are scattered by the wind and some setile in suitable places. Then, these spores develop into a tiny heart-shaped plant which makes male and female cells. These cells are, then, fertilized. A new root and stem grows into a proper fern and the tiny plant dies.
WHICH BIRD CAN SLEEP WHILE FLYING?
Lapion olbatrosses are very large buds . Their wingapons can reach to 13 feel three metres) and they noch may weigh as much as 11 kilograms. Their ronge extends to most of the North Pacific Ocean. An albatross has a dark brown back and white head, neck, and rump. Its eye patch is dark. Its bill is thick and yellow with o grey, hooked tip, Wings on dark brown above underneath is white with irregular brown black borders. The tail is dark brown-black with white coverts. The legs and webbed feet are flesh- pink. Although albatrosses are so awkward on lond yet they are graceful and impressive in flight. An albatross in flight can be so perfectly attuned to wind conditions that it may not flap its wings for hours, or even for days, as it can sleep while flying, li takes advantage of the air currents just above the ocean’s waves to soar in a perpetual graceful motion. Albatrosses live from forty to sixty years. They can stay out of sea for as long as five years before returning to the same island on which they were born
WHICH IS THE ONLY CAT FOUND IN THE DESERT?
lives in deserts. It is found in Norih Africa, the Arabian peninsula The sand cal (Felis margarito) is the only member of the callamily the Turkmenistan, Uzbekistan, and western Pakistan. The sand col hes numerous adaptations that enable il to survive in the desert. To instance, the padding on the soles of its feet is well suited to walking over loose sondy soil. Also, the sand cat does not need to drink water; it gets all the moisture it needs from solid foods. It conserves water by spending the heat of the day in a burrow dug in sand, under bushes of rocks. The sand cat has dense for that is sandy or greyish-ochre in colour. Its large ears can swivel to funnel sounds into its inner ears, while its large middle ear cavities are sensitive enough to hear the small scratching sounds of burrowing rodents. The distinctive triangular ears of the sand cat, which are large in proportion to the rest of the cat’s head, are particularly sensitive. The length of the sand cat is 17.5 to 22 inches (45 to 57 centimetres). The sond cat is mainly nocturnal (active al night) and feeds on rodents, hores, birds and reptiles VA AM World School 2132923
WHICH BIRD CAN FLY UPSIDE DOWN?
Hummingbirds are the only birds that can fly upside down. They do so because of their angled wing structure. However, a hummingbird can fly upside down only for a short period of time. A hummingbird can also fly backwards it does this while removing its bill from a tube flower. A hummingbird can rotate each of its wings in a circle, allowing it to be the only bird which can fly forwards, backwards, up, down, sideways or sit in sheer space. In order to hover, hummingbirds move their wings forwards and backwards in a repeated figure ‘eight’ much like the arms of swimmers treading water. Hummingbirds can move instantaneously in any direction, start from their perches at full speeds and don’t necessarily slow up to land. Hummingbirds can even fly short distances upside down, a trick roll-over they employ when being attacked by another birds. Also, a hummingbird is the only bird that cannot walk. It has to fly if it wants to move an inch. Its feet are only strong enough for perching. When it takes off, it doesn’t spring into the air like most birds do.
WHICH FISH PRODUCES AN ELECTRIC CURRENT?
An electric eel (Electrophorus electricus) is a long, snake-like freshwater fish, not a true eel that can generate electricity. It has electric current-producing organs within plates located on both sides of is spinal column. The plates run almost its entire body-length. The electric eel’s charge is 350 volts on the average but may be as great as 550 volts which is released by its central nervous system. The shock consists of four to eight separate charges, which last only two to three- thousandths of a second each. Used as a defence mechanism, the shocks can be repeated up to 150 times per hour. The most powerful electric eel, found in the rivers of Brazil, Colombia, Venezuela and Peru, produces a shock of 400 to 650 volts. One shock from an electric eel will not kill a person, but repeated shocks will. The electric eel grows to be almost 8 feet (2.5 m) long. Most of the internal organs are in the front of this fish; the rest of the body contains the electricity- producing organs (modified muscles). As this fish ages, its vision diminishes. The scales covering the body are tiny. With age, the amperage of the fish’s electric shock increases
- WHEN DOES A CATERPILLAR BECOME A BUTTERFLY?
Butterflies are insects with four large wings that feed either on the nectar of flowers or on fruits. Many butterflies are brightly coloured They have slim, hairlessbodies with club-shaped antennae. A female butter fly can lay 100 to several thousand eggs in its life. time. It lays the eggs near the kind of plant on which the young one can feed. Eggs hatch into cater pillars which begin to grow immediately. After sometime, the caterpillars develop a hard case and hang from a stemor leaf. This case can be either a cocoon or a chrysalis. It may take a few weeks or few months for the pupa to develop into an adult. After metamorphosis (transformation), the adult breaks its hard shell. Its wings are damp and crumpled. Soon, they dry in the sun and become firm to enable the adult to fly.
- WHEN DO BIRDS DANCE?
Some birds dance in order to impress their mates. At the beginning of the breeding season, birds begin to search their mates. It is the males who have attractive plumages and make a display of them.The palm cockatoo holds a stick in its claw and bangs it against a tree-trunk like a drummer beating a drum. Another bird which dances to impress a mate is the orange cock-of-the rock which lives in Brazil and Guyana. It spreads its wings, then leaps around, turning its head and tail from side to side. It continues to dance until it is exhausted. Birds of paradise have some of the most glorious feathers. The males show these off by dancing. The females, crested grebes, select their males by how well they dance. If the female accepts the male’s dance, then both dance. They mate when the bond between them is established.
- WHEN DO CHAMELEONS CHANGE THEIR COLOURS?
Chameleons are one of the 85 species of lizards. Most of the chameleons are found on the island of Madagascar and in the mainland Africa. A chameleon can look forwards and backwards at the same time because it has amazing eyes which can swivel in all directions. A chameleon changes its color when it is angry or frightened or when it is too hot or too cold or when it is sick. In order to match with the surrounding, it changes itself often. The color of the skin is controlled by pigment cells called melanophores. Lizards can also change their colours but chameleons are expert at this. They can change quickly to all sorts of colours.
- WHEN DOES A CYGNET BECOME A SWAN?
Swans live in or near freshwater. They can float for hours with the help of their webbed feet. They also have long elegant necks and pure white plumages except for the black neck swan of South America and the Australian black swan Baby swans are called cygnets. They are hatched with a complete covering of down(soft feathers) which is dark grey in color. Within 24 to 48 hours of hatching, they leave the nest and take to water. Cygnets are usually pale grey with grey legs that turn black as they grow. Right from the beginning, they can search for their own food but, at least, one parent guards and guides them. The dark downy plumage remains for two to six weeks. After that, it is gradually replaced by the juvenile feathers. The flight feathers develop at the last, which takes about 5 weeks to 5 months. By the age of six months, they are fully developed in plumages as well as in sizes.
- WHEN DO BIRDS MIGRATE?
Mass movement of animals and birds is called migration. They migrate in order to find food or due to the climatic changes or to breed. For example, every year in autumn, large flocks of swallows migrate to Africa. Swallows, swifts pie and martins migrate to Africa to escape the cold 3 weather because it becomes too cold for them to catch their prey, i.e. insects. Some migrations are daily, some seasonal and some are permanent. Migration occurs generally when they escape to avoid local food shortages. This generally occurs when the food is no longer available as seasons change. Food that was available in the summer will now be available for a longer time in the autumn and the birds fly towards the equator where food is more available. They often breed in the summer and then spend the non-breeding season in warmer places. Birds tend to commence migration in large numbers only when they have a favourable tail-wind.
- WHEN DO GLOW-WORMS GLOW?
The glow-worm is not a worm at all, It is the common name for various different groups of larvae and adult larviform females which glow through bioluminescence. Glow-worms may sometimes resemble worms, but all are insects. They are blackish and their bodies are very delicate. They are found in large numbers in tropical humid areas. They hide during the daytime among the vegetation. At night, light is generated in flashes by them. The light generating organ is located in the bottom of the abdomen and regulated by nerves. No heat is liberated by the light emitted by them. Two chemicals – luciferin and luciferase – are present. Luciferin blends with oxygen to light, whereas luciferase helps in this combination, i.e., acts as a catalyst. The light produced by them may frighten birds and prevent them from attacking these fireflies.
- WHEN DO BADGERS LEAVE THEIR NESTS?
Badgers are black-and-white faced animals with broad bodies and short but powerful legs. They live in sets or colonies underground. They throw out heaps of soil at the entrance to their tunnels. They leave their sets at dusk to search for food. Being nocturnal, they have each a very good sense of smell. They use their sense of smell to locate food such as earth worms and other small animals, fruit, cereals and vegetables. A badger may eat several hundreds of earth-worms in just a single night. Its excellent sense of smell is also useful for recognizing the scent signals left by other badgers for finding a mate and detecting danger. Badgers prefer hilly districts on the border of woods. They take care to keep their sets warm and clean. Damp bedding is thrown out and is replaced by fresh, dry grass or straw.
- WHEN DO WHITE HARP SEALS TURN DARK?
Harp seal is probably the most commercially important of the seals. Adults average about 2 m in length with a maximum weight up: about 180 kg., At birth, the pups are covered with long, luffy white fur from which they derive their common name of “whitecoats”. They are born with this colour for camouflage, to keep them safe from predators until they’re old enough to swim. Once they have grown a little, their white furs fall out. They all turn dark grey. The pups are nursed for only about 2 weeks and are then abandoned to fend for themselves. During that two-week period, however, they grow enormously on their mother’s milk which is rich in butterfat. When they are weaned, they weigh about 40-45 kg.Harp seals feed primarily on small fish and crustaceans. They are reported to be capable of diving to depths of 100 to 150 fathoms and remain submerged for up to 15 minutes. They apparently live for up to 30 years or more.
- WHEN DO TREES LOSE THEIR LEAVES?
Deciduous trees are the ones which lose their leaves once a year. There are a number of reasons for the loss of leaves. In fact, trees lose their leaves to conserve energy over the winter and prevent damage to the trees. In cool places, deciduous trees lose their leaves in autumn to cut their need for water in winter, when water may be frozen. Whereas in the tropics, these trees lose their leaves at the start of the dry season. Leaves fall because the layer of cork which grows across the leaf-stalk gradually cuts off its water supply. Finally, only the leaf is hanging on by its veins and is easily blown off by the wind. In autumn, the leaves turn brown, then red and golden because the green pigment chlorophyll breaks down. As a result, other pigments present in the leaves shine.Some of the deciduous trees of the cool climate are oaks, beeches, birches, chestnuts, maples, elms and lindens.
- WHEN DID PLANTS APPEAR ON LAND?
The very first traces of life, almost two billion years ago, were found the sea as simple plants, while land was lifeless. Then about 42% million years ago, a few tiny green plants emerged on land. They probably developed from some kinds of sea green weeds. The appeared like the mosses, liverworts and hornworts of today. Abou 400 million years ago, more complex plants appeared which looked like modern ferns. They were the first plants to possess roots, stems and leaves. By the time the first dinosaurs trodded the earth, large forests of gingkos and cycads had extended across the land. These were the first trees reproduce by seeds Pines and other conifers appeared about 300 million years ago. All these trees had their seeds on cones Flowering plants emerged about 150 million years ago. Such plants had an advantage over other plants as their seeds were properly shielded.
- WHEN DOES THE HORNED LIZARD EJECT BLOOD FROM ITS EYES?
Lizards are a group of 3,800 scaly skinned reptiles. Lizards have four legs and long tails. The back legs are stronger than the front ones and are used to drive the lizard forwards. The horned lizard ejects blood from its eyes for self-defense. It squirts a jet of blood from its eyes almost as far as 1 m to put off its predators. It is able to do so because it increases the blood pressure in its head which stimulates the membranes of tiny blood vessels in its eyes. Hence, the droplets of blood are ejected. When squirted into the eyes of an attacker, the blood acts as an irritant and diverts the attention of the attacker. The horned lizard has special features such as razor-like hard spines or horns. It has a flattened oval body and pointed fringe with scales throughout the sides of the body. These lizards are normally found in sandy areas.
- WHEN DOES THE FEMALE INSECT EAT ITS MALE?
A female insect eats its mate during or immediately after mating. The behaviour has been observed among female green anacondas which will mate with a number of males, then eat one of their suitors. This phenomenon is common among insects and arachnids, like black widows, praying mantises and scorpions. Among the redback spiders, relatives of the Black Widows, males are actually willing participants in the feast; they flip onto the female’s mouthparts. A Black Widow Spider belongs to the Arachnid family; it has no backbone. The spider got its name (Black Widow Spider) because the female usually eats the male after mating. Sometimes the male brings the female a present like an insect. So, the female does not eat the male so quickly. A Male Black Widow has a yellow patch on its back. It is shaped like an hour glass. A Female Black Widow has a red patch on its back. It is shaped like an hourglass.
- WHEN DOES THE MALE HORNBILL IMPRISON ITS FEMALE?
Like the toucan, the hornbill has an extremely large beak. The only difference is that the hornbill’s beak continues above the bird’s head to form a sort of knob that looks like a helmet. The hornbill has a large casque which is to be found on the upper mandible. The size and shape of this bill varies between the species. The bill is not solid but is filled with many air chambers and is very useful for reaching fruit on distant branches. The hornbill ranges in length from two to five feet. Most hornbills build their nests in a hollow tree. The male bird imprisons the female inside her nest by walling her in with dried mud while she hatches the eggs. The male does so till she cares for the young until they can fly. He leaves a small slit in the mud wall. Through this slit, he feeds his mate during the whole period she is sitting on the eggs. By enclosing the nesting mother, strong protection is given from deadly predators like birds and small carnivorous animals.
- WHEN DO WALRUSES USE THEIR TUSKS AND WHISKERS?
The tusks are huge canine teeth and both the male and female walruses have them. Tusks are made of ivory and grow to be two feet long in the cows and four feet long in the bulls. Bull tusks are straighter thicker and heavier. Walruses use their tusks for several purposes. Bull walruses fight or joust with other bulls during mating season with their tusks. They do so to earn the right to mate. Both male and female walruses use their tusks to pull themselves out of the water and to crack breathing holes in the ice during the winter. These tusks are, therefore, very valuable to these animals. The walrus has big whiskers. It uses its whiskers to feel around until it finds food. Then, it blows to get the food loose or to make it move so that it may get it. It needs the food to move because it can’t get to it because of its tusks. Walruses mainly eat bottom dwelling invertebrates. They include clams, snails, crabs, shrimp and worms.
- WHEN IS THE MUSK OX IN GREAT DANGER?
The musk ox lives in the frozen tundra of northern, Alaska, Canada, Ellesmere Island, Greenland, Norway, Sweden and Siberia. No other hoofed animal lives as far north as the musk ox. The musk ox can live in the harsh conditions of the Arctic tundra because its 24″ long hair and woolly undercoat ward off frost and provide insulation. The male has thick horns that almost meet on top of its head in what is called a “boss”. The homs curve down besides its face and out at the ends. The female has smaller horns without a boss. Instead, the top of her head is covered with whitish hair You might not believe, but the little mosquito is very dangerous to the musk ox. It is actually a danger to most animals living in the Arctic. The reason behind it is that the mosquito carries a lot of diseases. When it bites the musk ox, it can cause a lot of infection to the musk ox. There aren’t a lot of areas where a mosquito can bite the musk ox. So, it usually goes after its nose.
- WHEN WAS CORN FIRST GROWN?
Maize or corn is the second most important crop around the world after wheat. Rice comes third. Corn was first grown by the Mayan Aztec and Inca Indians more than 5,600 years ago. The Indians used the sugar-filled leaves of the corn plant as “chewing gum, immature corn as a fresh vegetable. The dry, mature kernels of corn were ground into flour. Corn, like all cereals, is a kind of grass. Corn is the most widely distributed crop in the world. Corn can grow at altitudes as high as 12,000 feet in the South American Andes Mountains and as low as the sea level. It can alsogrow in tropical climates that receive up to 400 inches of rainfall a year or in areas that receive only 12 inches. There are many kinds of corn. Some kinds are popcorn, sweet, flour, flint, dent and pod corn. Corn stems have long, skinny leaves. At the end of the stem is a tassel that looks like silk threads. The cob or centre of the corn, that is inside the leaves, has thousands of seeds that are called kernels.
- WHEN CAN YOU GET AN ARTIFICIAL PEARL MADE?
About 4,000 years ago, the Chinese discovered pearls in oysters. The inside of an oyster’s shell is covered with a smooth shiny coating called mother-of-pearl. When an irritant, such as a grain of sand, gets caught inside the oyster’s shell, the oyster secretes the layers of mother-of-pearl to protect its body by coating the irritant. The coated grain of sand becomes a pearl. Man can force the oyster to produce a pearl by inserting an irritant into the shell. It takes the oyster two to three years to produce a good-sized pearl Cultured pearls are usually not perfect, but the Japanese have discovered that if you surgicallyinsert an irritant directly into the body of the oyster, it will produce a perfect pearl. Pearl divers can dive up to 80 feet with nose clips. The divers stay under water for about a minute and they scoop up the shells with their hands and put them in tubs. These shells float to the surface.
- WHEN WE CUT ONIONS, WHY DO OUR EYES GET WET?
It is not the strong odour of the onion that makes us cry, but the gas that the onion releases when we cut this member of the lily family. The onion itself contains oil which contains sulphur, an irritant to both our noses and to our eyes. Cutting an onion arouses a gas contained within the onion. The gas is named propanethiol S- oxide which then couples with the enzymes in the onion to emit a passive sulphur compound. When this upwardly mobile gas encounters the water pro duced by the tear-ducts in our eyelids, it produces sulphuric acid. In response to the caustic acid, our eyes automatically blink and produce tears which irritate our eyes andwhich flush out the sulphuric acid. Another response to rid the eyes of a foreign substance is to rub them with the hands. This often worsens the situation because the hands are coated with the caustic, sulphuric acid producing oil from cutting the onion, which we, then, rub directly into our eyes.