Who’s brighter: Girls or Boys?


               There is a difference of opinion on this question. People have various explanations; some say that girls are brighter than boys while others have an opposite view. Scientists have yet to establish a logical scale by which it can be established that one sex is smarter than the other. Here are some facts which provide some sort of answer to this question.



               The average brain weight of males is slightly more than the average brain weight of females but the average body weight of men is more, therefore in both sexes the brain weight makes up about the same percentage of total weight. Difference in brain size is not of much importance. All human beings, male and female, have such a large number of nerve cells in their brains that a few more or less do not make any significant difference.



               Various tests have been conducted on a group of girls and boys and results have come almost the same. In tests, dealing with skills, the average score for girls is higher. In tests of technical and mechanical ability, boys have a higher average. But these figures are not very important because these may not be a good measure of people’s abilities. Also this is only an average data on certain tests, one sex may score more than the other but the results are almost same in other tests.



               Girls and boys are treated differently right from their childhood. Girls are usually given dolls to play with while boys get electrical and mechanical toys. Therefore, girls are expected to be less technical than boys. But now time is changing. More and more girls are competitively working with boys in similar fields. That is why their capabilities are becoming equal. This implies that it is the kind of upbringing and training that decides the ability rather than gender considerations.



               At present we have no scientific evidence by which it can be proved that which sex is brighter. Neither sex has a monopoly on any special mental ability. Individuals of both sexes deserve every possible chance to develop their abilities and to become whatever they want to be. It would be incorrect to judge brightness on gender grounds.



 


Which fish spits at insects?


               Fishes are the most numerous among vertebrates and their species number more than 30,000 which is more than all the other backboned animals put together. Each group has its own way of gathering food. The archer fish is such a fish which can shoot down insects from overhanging vegetation with water pellets. Its aim is quite accurate and it can easily dislodge a fly or a beetle about four feet away, so that it falls into water. The archer fish then dashes on the insect and eats it up.



               It is interesting to find out how the fish is able to project drops of water accurately over such a distance. The roof of its mouth forms a long groove. If the fish suddenly closes its gill covers, water is forced from the gill chamber into the mouth. At the same time the tongue is raised so the grooves become a long tube from which water squirts in a line of drops.



               Archer fish is a fresh water fish and belongs to the family Toxobidae. It is found in India and Indonesia. It got its name from the way it captures its food. Archer fish can also live in sea water. Toxotese jaculator is the most commonly known fish of this family. Its length can be upto 18 cm. Five groups of this fish have been studied. These fishes generally feed on insects. 


How do plants protect themselves from frost?

            There are over 350,000 kinds of plants in the world. All these continue to struggle to survive against storms, rains, sun and snow. There are some which die due to cold in winters, although before dying their seeds are spread on the ground so that in the autumn they can give birth to new plants. However, there are some plants which are able to protect themselves against winter.



            These plants are able to protect themselves against winter frost by a special method. They spread their leaves and flatten them against the ground. The warmth in the soil enters their leaves and the plant is protected. Some other plants like myrtle and heather allow their upper parts to die but their stem remains alive. Stems act as storage organs, both above and below the ground. These produce buds and thus restore their species. Many plants hide themselves under the soil to escape from the cold, these include tubers, bulbs and roots which store their food according to their need. When summer comes they push out green leaves and new buds.



            Sometimes artificial methods are used to protect plants from frost, e.g. oil heaters called smudge pots are used in the region where citrus fruits are grown. In some places large fans are used to keep the cold air moving so that frost is not able to get deposited on the fruit trees.




How do different animals move?


There are millions of animals found on earth that moves about in hundreds of different ways. Some walk or run, while some others jump, crawl, swim, fly or glide.



The various types of movements of different land animals are as follows.



(a) Walking: Four legged animals walk by moving the fore-leg of one side together with the hind-leg of the other. This is the basic movement of animals with limbs. Insects which have six legs move fore and hind legs of one side with the middle leg of the other side so that the body is always supported firmly by the other three legs.



(b) Pacing or ambling: Elephants, giraffes, camels and a few other animals move both legs of the same side simultaneously.



(c) Trotting: This type of movement is characteristic of horses, cattle and many other four-legged animals. It requires a little effort and can continue for long distances.



(d) Galloping: In this type of movement all the four feet remain in air for some distance. This is very tiring. Horses and cheetahs can gallop at a high speed.



(e) Jumping: Kangaroos, frogs, grass hoppers, and fleas are excellent jumpers. They can jump to different heights.



(f) Contracting and expanding: Creatures like earthworm, slugs and snails move by passing a wave of contraction along their body. Among these animals waves of muscular contraction and expansion pass along the body from front to back.



(g) Crawling: A snake moves through muscle contraction and relaxation. It moves by wriggling along the ground or swinging its body in loops. It also crawls with the help of the overlapping scales on its belly with which it hitches itself on a rough surface effectively.



(h) Undulatory walking: This type of motion is peculiar to lizards. A lizard uses its legs for walking in the same way as a crawling baby. But because its belly rests on the ground, it undulate its body as well. Crocodiles, newts and salamanders also walk like this. 


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How do animals release their tension?

          Sometimes animals are caught in such a situation that they can neither run away from their enemies nor fight with them. In such situations they become very tense. Different animals react differently to get rid of their tense moments.



          To understand this mechanism of relieving tension let us take an example of a school boy who has done some wrong and is facing his teacher. He feels guilty and perhaps frightened also. He cannot run away or fight. He is caught in a tense situation, and somehow he must come out of it. So he does something looking incoherent like scratching his head or blowing his nose to fight off his tension. Such actions help him in relieving his tension.



          For instances, when a mouse is cornered by a cat and cannot escape, it will sit up and scratch its face with its forelegs. A bird which is frightened of a cat will make pecking movements (when birds start striking with their beaks). A monkey relieves its tension by uttering different sounds. Similarly, dogs relieve their tension by barking. All these actions are meant for getting rid of tension. These are called displacement actions. Animals act in such ways to regain their normal state. Sometimes they can cause harm to others. All these actions are their reflex actions. These actions help animals to survive.



          To demonstrate the reflex action a Russian scientist Ivan Pavlov carried out a famous experiment with some dogs. In this experiment, he showed some food to the dogs. Due to this their mouths got watered. At the same time he rang a bell. He repeated this for a few days and then began to ring the bell without showing the food. The dogs became so used to the association of the sound of the bell and the sight of the food that their mouths still watered even when food was not shown. This is called conditioned reflex action. This happens involuntarily when animals are trained for some purpose. They start doing these actions automatically. In a similar manner people learn studying and talking simultaneously.




How do living beings adapt to their environment?

               Adaptation is a biological term which means the process by which all living things change or adapt to new and unfavourable conditions for their survival. Thus human beings, plants and all other living things adapt to their environment for survival. 





               In plants, take the example of the oak tree. Since it grows in a moist climate, its green leaves require much water to carry on the process of photosynthesis. On the other hand, since the desert cactus cannot afford large leaves that would lose more water, its leaves are reduced to spines that grow out of a waterproof stem. To come to some animals, the beaks of birds are again adapted to particular ways of feeding. For example, preying birds like woodpeckers and kingfishers have sharp strong beaks to tear their prey.



               There are two kinds of adaptations: individual adaptation and group adaptation. In individual adaptation an individual adapts himself to new conditions automatically in his lifetime. Group adaptation refers to adaptation by a group. It is a slow process and occurs over many generations. For instance if a man’s job is such that he has to work during night time he would have to adapt to such a routine gradually. To begin with, he may have some difficulty in sleeping during the day but when adapted to the changing requirements after sometime, he would sleep easily. 


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Which animal can see with its eyes closed?


               There are about 2000 lizard species in the world including chameleon, iguana and skinks. Skinks are one of the two largest families of lizards. They are found in all the tropical countries but they are most abundant in Africa, East Indies and Australia. They belong to the Cincidae family. There are about 700 species of skinks. Skinks are shy and retiring, so people are mostly ignorant of them.



               Skinks have very thin, small legs. They have a smooth skin and a small pointed head. They can crawl over the uneven surface. Unlike snakes, thin jaw bones are fixed. Most of them are ground dwellers.



               A very strange characteristic of skinks is that they can see with their eyes closed. While burrowing or eating insects they close their eyes. They have a permanent, transparent eye lid cover over their eyes with which they close their eyes. As this lid is transparent, skinks can see with their eyes closed.



               Another characteristic feature of skinks is that they can squeeze their size during the squirming movement through the soil. In some skinks the feet look ridiculously small when compared to their body size and in others they get disappeared altogether.



               Some skinks lay eggs, others bear live young. These skinks include the tiny three-toed skinks of southern Europe and north Western Africa. They grow upto 40 cm long of which half is tail. Australian skink stores fat in its tail and looks the same from both ends. It feeds on fruits, insects as well as small animals.



               Now the question arises why skinks close their eyes? When skinks move in the dust, the dust can enter its eyes. So to protect against dust and sand it closes its eyes.



 


Which is the largest seabird?


               Albatross is the largest flying sea-bird. It can have a wingspan of 3.15 m (10 ft 4 in.) at full stretch. It belongs to Diomedeidae family and is found mainly in south of the equator. It has a long, heavy beak and long narrow wings which allow it to soar on the wind seemingly without effort for hours. Its body is about 1.2 metres long.



               There are more than a dozen species of Albatross. It experiences certain difficulty in taking off. It needs some wind and must run along the ground or paddle with its feet across the water for a long time before it can soar.



                Like other oceanic birds, albatross also drinks sea water. Although it normally lives on squid, it is attracted to ship’s garbage. It comes ashore only to breed in colonies on islands. It lays a single large white egg on ground in the open, which is incubated alternatively by the male and female parent. The growth of a young albatross is very slow. It attains flight plumage in 3 to 10 months, and then spends the next 5 to 10 years at sea, learning navigation and feeding techniques. Albatrosses live long and are among the few birds that die of old age.



               However, among the sea birds which use wings for swimming and not for flying, the largest is the Emperor Penguin of Antarctica. Standing over one metre high and weighing 40 kg, the Plum Emperor lives in the most remote shores of the great ice-bound continent.



               The largest ever recorded specimen of albatross was a very old male with a wingspan of 3.63 m. (11 ft. 11 inch). This was caught by the members of the Antarctic research ship in the Tasman Sea on 18 September, 1965.


Where do crabs climb trees?


               It is established by the scientists that the most successful free living kinds of animals judged by the number of species and standing stocks of living substance, have come from marine surroundings.



               In 1964, Sir Vernon Wigglesword had suggested that, at first these animals might have lived along the shore lines and later moved in two directions. A part colonized the open sea and ocean deeps to give rise to crabs, crustacea etc and the other part moved to land areas.



               Crabs are mainly marine animals - although some live in fresh water or land. They are ten-legged alert carnivores that act as scavengers. There are many species of crabs worldwide; such as European crabs, shore crabs, edible crabs, fiddler crabs, river crabs, common hermit crabs and robber crabs.



               Among all these, robber crabs or commonly known as ‘coconut crabs’ are well adapted for living on land, although their larvae first live in the sea. But if an adult robber crab is left under water beyond 24 hours, it will be drowned ultimately. These are the crabs which can climb trees.



               The robber crab (Birgus Latro) is an extremely large land crab of South-West Pacific and Indian Ocean. Adults of robber crabs are about one metre long (40 inches) and weigh about 15-17 kilograms. A robber crab uses two large chelae or pincers to pound or chip coconuts to eat the soft white portion of the coconut. They climb coconut trees to detach coconuts from tree tops through they are quite unable to get inside a coconut on their own. They apparently eat coconut meat already broken into the ground by other means.



               The colour of a grown crab ranges from light violet to brown and deep purple with black strips on their legs. The female lays her eggs in sea. In larval state, it lives in water, feeding on small organisms. After about a month when it is grown to intermediate stage, it leaves water to live in a shell for 3-4 weeks. It then discards the shell and buries itself in moist sands, and transforms into an adult robber crab. Its meat is a local delicacy. 


Why do dogs pant in summer?

               A dog, like a cow, an elephant, or a man, is a mammal. All mammals are warm blooded, or homothermic animals. In the animal world only mammals and birds are warm-blooded creatures. The rest of the animals are cold-blooded or ectothermic. A warm-blooded animal has a relatively constant body temperature, while the temperature of cold-blooded animals changes according to surroundings. 



               Heat is being constantly produced in our body. A part of it escapes through our skin. We have sweat glands under our skin and sweat comes out through small pores in it. When sweat evaporates, it absorbs heat from the body producing a cooling effect.



               Unfortunately, not all mammals can use this method to get rid of their body heat.



               For example, a dog has few sweat glands and, therefore, cannot sweat like us. Similarly, tigers, lions, cheetahs, etc. cannot sweat much. Birds and rats also cannot sweat.



               A dog has a different mechanism to control its body temperature. It does so by hanging its tongue out. When a dog pants, it takes in air through the nose and gives out air through the mouth. The saliva in its mouth evaporates. Evaporation of saliva produces a cooling effect and the dog feels comfortable. This habit of panting is simply a natural urge of a dog to control its body temperature in accordance with its surroundings.



               An elephant also maintains its body temperature in a very interesting manner. Its skin is very thick and not much heat can escape through it. However, the skin on its ears is much thinner. The elephant, therefore, tries to get rid of the body heat through its ears. Nature has given the elephant very large ears which it can flap in a bid to lose heat. The skin of our ears being quite thin, the ears feel cold on a winter day.



 


Does any animal have three eyes?


               Tuatara or Sphenodon punctatus is a strange lizard like animal that has three eyes. It is the only animal in the reptile group which is placed in a separate sub-group rhynchocephalia. Although it resembles lizards, it is truly a precious living fossil, since this reptile order goes back to the time of the dinosaurs. Tuatara is found only on the islets of New Zealand. A full grown male weighs upto 1 kg but females weigh only half that of a mature male of similar age.



               The strange thing about this animal is that it has three eyes. The cone like third eye is called the pineal eye. This eye is situated in a hole between the head and brain. It has an eyelid over the third eye which closes horizontally. One can’t say anything about the use of the third eye of this animal but certainly it had some use for these prehistoric animals.



               This animal is active at night. Generally it lives in burrows often in company with sea birds. It is a very shy and retiring animal. It eats insects, other animals like frogs, rats and eggs of birds also.



               The average life of a Tuatara usually does not exceed 77 years, but some Tuataras may live upto 100 years. Male Tuataras are unusual in the sense that they have no copulatory organ; their matings are accomplished by cloacal apposition. Female Tuatara lays 8 to 15 eggs in the spring, at some distance from its burrow. Hatching of eggs occurs in the next summer which means that hatching takes about one year of time.



               It is a unique animal and represents a whole vanished order of reptiles. All other species except this one became extinct and only this particular type has lived unchanged till the present day. In captivity it can live upto fifty years only.



               This strange animal is now facing extinction. The government of New Zealand has been making great efforts to prevent the extinction of this animal.



 


Which is the most beautiful reptile?

               There are about 5000 species of reptiles. These include lizards, tortoises, crocodiles, etc. Most of the species of reptiles live on and but there are some which live in water. Their length varies from 5 cm to 10 metres. The smallest lizard is found in tropical regions while python is the largest snake. All reptiles are cold-blooded animals. Although they are found everywhere on earth but they are most common in tropical regions. Do you know among all reptiles which are the most beautiful?



               The European Green Lizard is the most beautiful reptile. It is the second largest lizard to be found in Europe — the male reaching a length of 16 inches, its tail alone being 10 inches long. 





               Green lizards are found throughout Europe although they do not have natural habitats in Great Britain. Attempts have been made to establish colonies but it is believed that the climate there is not really warm enough for their survival. They are most commonly seen in Mediterranean countries, basking on the rocks and among the ruins. There is also another kind of lizard known as Arizona Lizard. It has a bright black and white colour in its body.



               Green lizards are sold in petshops. Their elegant reptile shape and attractive colouring attracts people to buy them. It is not difficult to keep them as pets. They only need proper care. They feed on insects, spiders and worms.



               Most lizards are harmless. The only lizards with a poisonous bite are the Gila Monsters with black and white marks on their body.



 


Do snakes love music?


               All of us have seen snake charmers playing their pipes before a snake. When a snake charmer plays his pipe, swinging it backwards and forwards or jerking up and down, the cobra raises its head and moves in rhythm with the music. There are many folklore about snake’s love of music. Some snake charmers even claim that they can summon snakes by playing on the pipe. Do snakes really love music?



               The snakes do not have an auditory structure. They have a bony rod called columella auris. This bone extends from the fenestra oxalis to the quadrate bone. This bone has a special structure which helps it to detect the ground vibrations. But it cannot detect vibrations in the air. Due to this a snake detects an approaching ball.



               In order to verify whether snakes can detect the vibrations produced in the air or on the ground, a number of experiments have been conducted with different species of snakes by P.J. Deoras at the Haffkins Institute, Bombay. He put a snake inside a tin box and studied the effect of soft music near the tin box. He found that any sound that caused the tin to vibrate made the cobra to raise its head. He took a snake charmer inside his snake farm and found no response for air borne music. However, it responded to ground music.



               Experiments on five other species were also conducted. And again the findings were that the snakes did not respond air-borne music. However, they responded to the music of drum which creates vibrations in the box or earth.



               In short, it can be said that snakes are very sensitive to sounds that create vibration on the ground. Because of this fact, the snake charmer hits his pipe with the ground to make the vibrations reach the snake. A snake charmer also hits the snake with the pipe and tries to excite him. Actually it moves its body only to keep an eye on the moving pipe.



 


Why do animals have a tail?


            All vertebrates except man have a tail. According to scientists, there was a time when man also had a tail. But when he stopped using it, it fell into disuse and became extinct. We still have a mark of a tail on our body. Do you know what the usefulness of a tail in different animals is?



            The tail is found in the post-anal part of the body. It has different uses in different animals. In fishes it is surrounded by a tail fin and plays an important part in providing forward thrust. They have different types of tails. These help them in swimming and providing the upward movement.



            In crocodiles and whales the tail acts as a powerful organ for locomotion. In frogs and toads the tail and tail-fin are present only in the larval states and absent in the adult. Crocodiles use their tails for defence and also to attack their enemies. 





               All reptiles possess a well-developed tail. The length of these tails is different in different reptiles. Tortoises and turtles have short tails while lizards have long ones. If somebody attacks a lizard, it can break a part of its tail. It is a defence mechanism. Reptiles perform wriggling movements with the help of their tails. Lizards after sometime regenerate a new tail. In chameleon the tail is quite long. It can be rolled downwards to coil round the branches for extra grip. The tail of snake is small in size. It acts as a storehouse of fat. The tail of the sea snake is small in size and oar-shaped, and helps it in swimming.



               Real tail in birds is extremely short and stumpy. It gives a support for the feathers. Feathers help birds in flying.



               Most mammals have well developed tails. With these they can get rid of flies. Men and apes do not have such tails. Whales have two lobes of tail fin of which one is at right and one, at left. It helps it in swimming. The tails of kangaroos and squirrels act as a balancing organ during walk and leap. During winter season when squirrels hibernate, the hairy tail acts as a blanket. Rabbits use their tails for providing warning signals. Peacocks display their tails to attract the opposite sex. In this way we see that different vertebrates make use of their tails for some purpose or the other.



 


What is appendicitis?


               The appendix is a part of the intestine in the human beings. Its full name is the vermiform appendix. The word vermiform means worm-shaped. The appendix is found on the lower right side of the abdomen. It is found at a place where our small intestine joins the large intestine. This is called caecum. It is in the form of a tube whose one end is closed and the other opens into the caecum.



               In human beings the appendix is usually three to four inches or eight to ten cm. long and less than half an inch wide. It was probably a necessary part of the digestive system thousands of years ago and perhaps helped in cellulose digestion. The organ is believed to be gradually disappearing in human beings and is often referred to as a vestigial organ — those organs or parts now disappearing for being in disuse but ancestrally well developed.



               The appendix has muscular valves, ordinarily capable of expelling the mucus secretions of the appendiceal valves into the caecum. If anything blocks the opening, the continued secretion and the bacteria within the organ build up pressure. It may also be invaded by germs. This causes the whole area to become sore and swollen. The painful inflammation of the appendix is medically termed as appendicitis. A person experiencing an attack of appendicitis may feel abdominal pain in the right lower region of the abdomen. He may feel nausea or have diarrhoea. There can also be slight fever unless the appendix bursts. Recurrent mild attacks of appendicities in children are often diagnosed as ‘bilious attack or disorder of biles’. The only safe plan is to watch such cases very carefully and immediate attention should be given for proper treatments.



               In acute cases, surgical operation is needed. It is operated on after giving general anaesthesia. The appendicitis is caused usually when bits of undigested food stick in the opening to the appendix and block it. This gives bacteria a warm, closed place where they can grow and multiply and produce a painful swelling.