Acid Rain Causes

          The term acid rain refers to the fall of acids mixed with rain and snow. The main cause of acid rain is the gases emitted by the factories and motor vehicles which pollute the atmosphere. Mainly sulphur dioxide is responsible for acid rain which is produced in the burning of fossil fuels. This gas is also produced by natural phenomena like volcanic corruptions; forests fires etc. sulphur dioxide reacts with water vapor and forms sulphuric acid in the presence of sunlight. This acid gets mixed with rain water or snow flakes and fall on to the earth. Similarly, motor vehicles burn petrol and diesel and produce oxides of nitrogen. These oxides produce nitric acid with rain water. In 1872, Robert Angus smith was the first person to discover acid rain.

 Emissions of sulfur dioxide and nitrogen oxides react with water vapor in the atmosphere to create sulfuric and nitric acids

Acid Rain has reduced the sparkle of the Taj Mahal

            The acid rain may occur thousand of kilometer away from the source of gas emission. During the gulf war many oilfield caught fire and the smoke produced was so much that it reached even up to the Kashmir valley and turned the snow into black. Acid rain badly affects the marine life. The reproduction capability of fish gets reduced. Trees defoliate before time and the crops having edible roots get destroyed. The Taj Mahal at Agra and New York’s statue of liberty has lost their luster due to acid rain. Water lily plants get most affected by acid rain.

Continents

A little less than one-third of the earth’s surface is land mass and the rest is covered by water. There are seven large continuous land masses called continents. They are: Asia, Europe, Africa, North America, South America, Australia and Antarctica.

            According to the German geologist, Alfred Wegener, once the earth was a single land mass known as Pangaea. Nearly 200 million years ago this land mass broke into two parts- Laurasia and Gondwana land.

            According to Wegener’s continental drift theory, these two large land masses continued to drift away from each other. Present North America and Eurasia Europe and Asia emerged out of Laurasia, while the South America, Africa, Australia and Antarctica owe their existence to the Gondwana land. Thus the seven continents of the world appeared.

            The theory also explains that not only the continents but also the crust plates, which include both the continents and the oceans, drift. Thus the continents are undergoing changes even now. In fact, earthquakes are also caused due to the drifting of these crust plates.

Caves and Caverns

A cave is a natural opening in the earth that is big enough for a person or animal to enter. Most caves are formed by the erosive action of rain water or underground water on rocks such as limestone or dolomite. The water contains dissolved carbon dioxide which forms dilute carbonic acid. This acid dissolves the rock, forming passages and large open spaces. Caverns, caves and joint galleries are the result of this process.

            The other types of caves are lava caves, ice caves and sea caves. Lava caves are found near the base of volcanic mountain. Ice caves are formed within glaciers. Sea caves are formed in the coastal rocks by the action of sea waves.

            The early man lived in caves. Even today, some groups of people in Spain and the Philippines live in caves. Kentucky caves in the USA are well known such as the mammoth cave system which is the deepest cave in the world (563, 270 meters) deep and the fisher ridge cave system is the world’s longest cave, about 116 kms long. In India, the Ajanta and Ellora caves are quite popular.

 

Caverns are formed by the erosive action of rain or underground water

 Caves are formed by the erosive action of rain or underground water

Journey to the Moon

The three manned Apollo-11, which had enough space for astronauts to not only move about but also to stand erect within it, set out on a journey to the moon on July 16, 1969. The special feature of Apollo’s landing on the moon was that its two astronauts could touch the surface of the moon with the help of the four legged lunar module Eagle.

At 10.56 pm on July 20, 1969. Neil Armstrong set his foot on the surface of the moon. He was the first human being to put his foot on the moon.

            In his radio communication sent to the earth Neil Armstrong described it as one small step for (a) man, one giant leap for mankind. Therefore, Edwin Aldrin stepped out on the moons surface. Michael Collins remained aboard the Apollo 11 command module in orbit. The two astronauts spent around 2 hours 30 minutes on the moon. During this period, they collected samples of moon’s rocks and soil weighing over 20 kg.

            The total estimated expenditure on this US space programme at sending men to the moon, with Apollo 17 was around 2,554.1 million dollars. With a view to reduce expenditure space shuttle was invented by the US scientists. Space shuttle is a reusable manned space vehicle with a speed of about 28,000 km. per hour. The first space shuttle Columbia was launched on April 12, 1981. The USSR launched a similar space vehicle named buran in September 1988 which returned to the earth safely after successfully completing the mission.

            After the success of this mission, the following persons made journey to the moon under the Apollo programme. They brought with them rocks and soil weighing 3,800 kg.

Apollo 12        : Conrad, Bean, Gordon November 14,     1969

Apollo 14        : Shepard, Mitchell, Roosa January 31, 1971

Apollo 15        : Scott, Irwin, Worden July 26, 1971

Apollo 16        : young, Duke, Mattingly II april 16, 1972

Apollo 17        : Cernan, Schmitt, Evans December 7, 1972

 

Apollo-11 Moon Landing

 Apollo 11 Lunar Module

Neil Armstrong set his foot on the Moon on July 20, 1969

Surface of the Moon

The Plants Kingdom – Algae

Algae are the simplest kinds of plants. They contain chlorophyll; therefore, they can make their food by photosynthesis. They lack vascular bundles, i.e. they do not posses xylem and phloem. Their thallus lacks true roots, shoots and leaves algae include unicellular plants to very big multicellular plants. They do not form embryo after sexual reproduction. Commonly, algae are colored and they can grow up to 40 or 60 meters in length.

            Most algae grow in rivers, ponds, lakes and oceans. Some can live in moist places on land, mountains and near trees. A few species of algae are found on the ice in the Polar Regions and in hot water springs. Some of the blue- green algae can survive even at 70-80 degree centigrade. Some algae grow on plants and a few complete their life cycle inside some plants. Many algae are saprophytic and parasitic. The best known algae are probably the seaweed found at beaches.

            About 25-30 species of algae are used as food by man. The algae porphyra of phiopcae class is a common meal in Japan. In china, Nostoc commune is used as food. In India, algae are used to prepare ice-cream, chocolate milk, gelatin and beer. Some algae are poisonous in nature and can paralyze a person.

            We get carbohydrate, vitamins A, B, C, D, E and other materials from algae. Fish depend on algae for their food. Many algae obtained from oceans are rich sources of iodine, potassium and other minerals. Algae are a good fertilizer also. The red algae grow in large colonies and turn the water red. Some red algae also form islands.

Different species of algae

Poisonous Plants

The flowers and fruits of some plants look very beautiful and attractive but they may be poisonous. A few famous poisonous plants are the following.

            Strychnos nux-vomica is a poisonous plant found in Asian countries. Its fruit is of the size of an orange and it contains five seeds in it. Strychnine poison is prepared form these seeds. This poison stops respiration and causes death.

            The white flowers which flourish on the hemlock plant produce an unpleasant smell. A poison called caniine is obtained from its roots and seeds. This poison paralyses all the organs of the human body and causes death. The great Greek philosopher, Socrates had been given a cup of hemlock to drink as punishment.

            Colchicine poison is obtained from the seeds of meadow saffron plant. This poison is used for the treatment of arthritis.

            Apart from these plants, foxglove, monkshood, poppy, cherry laurel, thorn apple, caper spurge, laburnum, henbane, holly, honey suckle, buckthorn, toadstool, bittersweet, etc. are also famous poisonous plants. Many varieties of mushrooms are also poisonous. Many plants of the subhax group are also poisonous, which produce blisters on the skin coming in contact with it. Ivy is also a poisonous plant and produces allergy in the body.

 Foxglove

Hemlock Plant

Honeysuckle Flower

 Holly Plant

Meadow Saffron

Nightshade

 Poppy

Strychnos Nux-Vomica Plant

Toadstools

Environment - Ozone Depletion

According to meteorological researches the atmosphere is divided into five thermal zones- the troposphere- 10 km above the sea level; stratosphere 10 to 40 km; mesosphere 40 to 70 km; ionosphere 70 to 400 km; and exosphere above 400 km.

 Ozone Depletion - Effects of CFCs

            Stratosphere contains negligible amount of water vapor and dust. Strong jet streams blow in this layer which affects the weather of the earth. For convenience this layer may be divided into two parts called stratospheric layer and ozonosphere. Stratospheric layer exists only up to 25 km height and its temperature remains almost constant. Ozonosphere contains ozone and it exists between 25 km to 40 km. ozone is essential to life on earth because it acts as a safety shield for the earth. Ozone forms a hot layer by absorbing about 90% of short ultraviolet rays of sun which are harmful for the life on earth.

Ozone Depletion

            In nature ozone is formed from oxygen by ultraviolet radiations of the sun. These two gases remain in equilibrium or balanced condition. But recently oxygen-ozone balance has been upset by the excessive presence of chemical pollutants in the atmosphere. Scientists believe that ozone layer is becoming this over Antarctica.

            Man made chemicals especially chlorofluorocarbons adversely affect the ozonosphere. Freon gas is also a chlorofluorocarbon which is used in refrigerators. These chemicals are also used in air-conditions, aerosol spray and plastic foams. Free chlorine atoms of these compounds have disturbed the ozone equilibrium. Ozone depletion will cause dreadful disease like skin cancer and skin allergies. It may also have hazardous effect on plants and other animals. To save our earth we have to discover substitutes for chlorofluorocarbons which do not cause ozone depletion in atmosphere.

Tallest Trees

Pine, spruce, fir, cedars, juniper, cypresses etc. Are the famous coniferous trees. These trees bear unisexual cones. Male and female cones can be formed on the same plant or on different plants. The leaves of all coniferous plants are simple and they remain on the plants through the year. Therefore, these trees are called evergreen trees.

            The tallest trees of the world belong to this group. The red wood trees are considered to be the tallest of the world. These trees are now found only on the coastal regions of California. Their average height exceeds 90 meters and diameter is up to 5 meters. Their age is around 4,000 years. The tallest tree of this group was found in California in 1963. At that time, its tip was dried and its height was 112.10 meters. In 1970, its height was 111.60 meters. The tree is gradually drying up. The world’s tallest tree that is alive and is in good condition is the general Sherman of California, which is 85 meters tall. The trunks stem of these tress are used to build and cover roads.

            Among the flowering plants, eucalyptus regnans with broad leaves is the tallest tree of the world and present in Tasmania. It is 99 meters high.

Heights of some other plants:

Callie grass (5.5 meter)

Saguaro cactus (16 meters)

Tree fern (18 meters)

Bamboo (37 meters)

Giant kelp (60 meters)

Environmental Action Plan

My Pledge

I will never ask for carry bag.

I will carry my own bag.

I Do It Properly:

I don't litter. I use always dust bins.

Rally on World Environment Day

My Pledge:

I will buy only local varieties of fruits and vegetables.

I Do It Properly:

I organize a food festival with local traditional food items in our school.

Rally on World Wetlands Day

My Pledge:

I will use bicycle for short distances

I Do It Properly:

I organize a flower show with local flowers and flowering plants.

I organize an exhibition on solar energy and appliances.

I grow native plants for flowers and fruits.

Rally on Clean and Greens Day

Underground Water

The rain water and the water from melted ice that reaches under the surface of the earth through pores and cracks are called underground water. Some underground water may originate from the steam rising from molten rock materials deep within the earth. Erosive action of water on limestone rocks turns their pores into such big sink holes that even a river if that is drained into them would disappear. Fell Bank River in Yorkshire sank into a 111- meter deep hole.

            Springs and artesian wells owe their existence to the flow of underground water. Artesian wells are of great economic importance in the mountain ringed basins in the semi-arid climatic regions of the world. There exist more than 18 thousand artesian wells in the world’s largest artesian basin in Australian. Artesian wells have been sunk in the Terai region of India for irrigation and supply of drinking water. The underground water is very useful in our daily lives. It not only provides us the drinking water but also a valuable source of water for irrigation purposes.

Test for Starch

Preparation of Dilute Iodine Solution

                                                          

Take a test tube or a cup and add few drops of Iodine solution to it. Then dilute it with water till it becomes light yellow/brown in color.

Dilute Iodine Solution

Take a sample of food item in another test tube. Add a few drops of dilute Iodine solution on the sample you have collected.

Observe the change in color. What do you find?

If the substance turns dark-blue or black it contains starch.

List of Specialist Doctors

Allergist: A medical practitioner specializing in the diagnosis and treatment of allergies.

Andrologist: A physician who performs laboratory evaluations of male fertility.

Anesthesiologist: A specialist who administers an anesthetic to a patient before he is treated.

Audiologist: An audiologist is a trained professional who measures hearing loss and can fit hearing aids.

Cardiologist: A specialist who treats disorders of the heart and circulatory system.

Dentist: A person qualified to treat the diseases and conditions that affect the teeth, gums, and the repair of teeth and extraction of teeth.

Dermatologist: A doctor who specializes in the physiology and pathology of the skin.

Diabetologist: A doctor who specializes in the treatment of diabetes mellitus.

Endocrinologist: A specialist in the treatment of hormone diseases, such as diabetes, metabolic disorders, thyroid diseases and hypertension.

Gastroenterologist: A physician who specializes in diseases of the gastrointestinal tract.

Gastrologist: A gastrologist is a doctor who studies the gastric system such as the stomach and its diseases.

Gynecologist: A specialist who treats female reproductive and sexual organs.

Hematologist: A doctor who specializes in diseases of the blood and blood-forming organs.

Hygienists: A person skilled in the practice of hygiene.

Immunologist: A medical scientist who specializes in immunology.

Internist: A specialist in internal medicine.

Leprologist: A specialist who devotes special attention to the study of the nature and origin of leprosy and to its treatment.

Neonatologist: A physician specializing in the care of newborns.

Nephrologists: A specialist in the treatment of kidney diseases and disorders of the kidneys.

Neurologist: A specialist in the treatment of disorders of the brain, spinal card and the rest of the nervous system.

Obstetrician: A specialist who takes care of woman during and immediately after the period of pregnancy and birth.

Oncologist: A specialist in the treatment of many types of cancer.

Ophthalmologist: A specialist who studies and treats eye diseases.

Orthopedist: A specialist who treats injuries and diseases of the bones.

Orthoptist: A specialist in non-surgical treatment of visual disorders caused by imbalance of the eye muscles, such as strabismus.

Otolaryngologist/ ENT Specialist: A specialist in the disorders of the ear or nose or throat.

Pathologist/Diagnostician: A doctor who specializes in medical diagnosis.

Pediatrician: A specialist of children’s diseases.

Perinatologist: An obstetrician specializing in perinatology.

Podiatrist: A specialist in the diagnosis and care of foot disorders, including their medical and surgical treatment.

Psychiatrist: A specialist attempts to alleviate mental and emotional disturbances and disorders.

Pulmonologist: A specialist in the treatment of the lungs and respiratory system.

Radiologist: A medical specialist who uses radioactive substances and X-rays in the treatment of disease.

Rheumatologist: A specialist in the treatment of arthritis and other disease of joints, muscles, and bones.

Serologist: A medical scientist who specializes in serology.

Surgeon: A surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether that of a human or other animal, for a specific reason such as the removal of diseased tissue to repair a tear or breakage.

Toxicologist: A specialist who studies the nature and effects of poisons and their treatment.

Urogynecologist: A physician that deals with women's health, especially with the health of women's reproductive organs and urinary tract.

Urologist: A specialist in the treatment of the urinary organs in the female and urinary and sex organs in males.

Venereologist: A specialist in the treatment of sexually transmitted diseases.

Left Handed People

Why are some people left handed?

Most of the people in the world do most of their work with the help of their right hands; but 4% of the world population is left handed. If we go through the history of mankind we find that many of the great men of the world have left handed. The world famous sculptors Leonardo Ad Vinci and Michelangelo both were left handed. Parents of the left handed children usually feel worried about this habit and make efforts to correct it. But psychologists believe that if a child is a left handed he should not be forced to hanger this habit.

People whose right hemisphere of the brain is dominant are left-handers

            If we examine the constitution of the body carefully we will notice that our body is not fully symmetrical. There is a little asymmetry between the left and right side of the body. Generally right side of the body id lightly heavier than the left parts. Even the functions of these parts are somewhat different. Usually the left half of the brain is predominant over the right half. In such cases, the nerves from the brain cross over at the level of the neck and go to the right side of the body. Such persons are right handed. Most people of the world fall under this category. But there are cases where right half of the brain is predominant over the left, nerves coming our of the brain pass on to the left parts of the body. Such people perform all their functions with their left hands. That is why some children write and even eat food with left hand.

            Have you wondered why left hander’s are in such a minority in comparison to the right hander’s? Scientists have not been able to solve this riddle till now. Since the number of right hander’s is so large, the door handles, locks, screwdrivers, and motorcars, musical instruments all are designed keeping in view the convenience of the right hander’s. Even buttons are fixed on the right side for the same reason. The left handed people experience some difficulty in handling all these but get used to the functions with a little effort.

The Human Digestive System

How do we digest food?

            The human body requires a constant supply of food in order to carry out its numerous activities. The food we consume performs two main functions in our body. First, it supplies proteins for the growth of the body and second, it supplies energy to the tissues for the day to day work.

The Human Digestive System

            The process of digestion is very complex and elaborate. Digestion begins at the mouth. When we chew food, the saliva produced in the mouth moistens it. The saliva contains a substance called ptyalin, which converts the starch of the food into simple sugar. This is the first stage of digestion. Therefore we should swallow the food only after chewing it properly.

            After that, the food material passes through the esophagus to the stomach where the gastric juices get mixed with it. The walls of the stomach secret juices containing an enzyme called pepsin and hydrochloric acid. Pepsin breaks down the molecules of proteins into peptones.

            From stomach, the food then enters the small intestine, where it mixes with three other digestive juices- bile, pancreatic juice and intestinal juice. The liver produces bile. Its main function is to digest the fats. The pancreatic juice is basic in nature and neutralizes the acids. It also digests the proteins. The intestinal juice converts sugar into glucose. Here, many enzymes also mix with the food. The digestion of food mainly takes place here. The digested food is them absorbed by the blood vessels present in the wall of small intestine. The remaining waste of the food now goes to the large intestine and is finally excreted out of the body as faeces through the anus.

Intoxicants Affect Our Body

How do intoxicants affect our body?

            Alcohol, wine, cigarettes, bidi, opium, intoxicating hemp ganja and bhang, cocaine or morphine etc. are known as intoxicants. Many people indulge in them for various reasons but they have a number of harmful effects on our health. The uses of these are also considered a social evil.

            People generally consume tobacco in the form of bidi, cigarettes or Hubble bubble hookah. Some people chew it raw. Tobacco contains a powerful poison called nicotine and 26 other poisons. Even though it is contained in extremely minute quantities, they harm our body to great extent. When we smoke, our blood absorbs some of the nicotine. This nicotine excites our nose and throat. This also causes coughing. Smoking increases blood pressure. It accelerates the heartbeat and cases heart ailments. It also affects the body temperature and blood circulation. Recent scientific researches have shown that smoking causes lung cancer too. It has also been proved that smoking shortens the lifespan of people. Moreover, indigestion, peptic ulcer and cancer of the mouth are also among its after effects. What is worse is that nicotine is an addictive substance and those who are used to it find it impossible to give up smoking.

            Use of alcohol in the form of liquor is also very harmful for our heath. Some people carry the wrong impression that drinking makes the body more active. But this is far form the truth. All the physical process gets slowed down when one consumes alcohol. More liquor like whisky, rum or brandy contains a high degree of alcohol. The alcohol has unsuitable effects on our body. As soon as it enters our body and mixes with the blood, it immediately starts influencing some areas of the brain. As a result of this, the individual starts getting intoxicated. His vision gets disturbed. And his thoughts become illogical and he finally becomes senseless.

            Accidents caused by drunken people are very common these days. Statistics show that one cut of every five accidents is caused by people who are drunk. Drinking also reduces the control over muscles. Prolonged drinking causes dangerous diseases of the liver.

            Some people take many types of pills of relieve themselves of pains and mental tensions. These are very dangerous for health. Excessive use of these weakens the memory. Once you develop the habit of taking intoxicants, it becomes very difficult to get ride of them. The use of LSD, brown sugar, opium, ganja, and charas is certainly an invitation to death. These substances adversely affect the body and brain and give birth to crimes in the society. We should, therefore, always avoid using them.

            To deal with these problems many reform organizations have established to treat the patients.

The Blood Group Varies from Person to Person

Why does the blood group vary from person to person?

            Even though the blood of all the human beings looks alike, in reality, it is not so. Our blood is mainly composed of red blood corpuscles, white blood corpuscles, platelets and plasma. It has been observed from microscopic investigations that molecules of antigens found on the surface of red blood corpuscles are different in different people. Antigen molecules are a kind of proteins that stimulate the production of antibodies. It is this difference in the antigen molecules that gives rise to different groups of blood.

Blood Compatibility

            In the year 1900 Dr Karl Landsteiner discovered two kinds of antigen- A and B type. He was awarded the Nobel Prize for medicine in 1930 for this discovery. Blood containing A type antigen was classified as A group, while that containing B type as B group. Subsequently, it was discovered that the blood of some people contains both A and B type antigens. This type was classified as AB group. The blood that contained neither A nor B type antigens was called O group. Thus the blood of all human beings has been divided into four groups. Studies made till now have revealed the existence of more than 200 groups of human blood.

            However, as far as the transfusion of blood of nay patient is concerned, only the aforesaid four groups of blood are important. Before transfusing blood to any patient, it is essential to get his blood group tested. It is very essential to match the blood of the patient with that of the donor before transfusion. It has been found that the blood of even real brothers and sisters may not be of the same group. On the other hand, the blood of two individuals belonging to two different states may be of the same group.

            If the wrong blood is transfused to patient, he can die, because antigens of different classes cannot combine with each other. However, blood plasma of one individual can be given to another because it is the same in every body.

            Landsteiner and Alexander S. wiener discovered another important blood antigen in 1940. This additional factor is called the rhesus antigen or Rh factor.

            Rhesus antibodies do not occur in naturally blood groups- both for

recipients and donors. AB groups are called the universal recipients whereas O is the universal donor.