Tell Me Why...?

A plant needs roots for two chief reasons: 1. As a means of anchoring itself to the ground. 2. To absorb water and minerals from the soil. The roots of most plants grow in the soil. By elongating their tips, roots are always coming into contact with new portions of soil. Thousands of tiny hairs project from the surface of the young root which absorb the materials from the soil. Types of roots: 1. Some plants have large bulbous roots called taproots. 2. Grasses have fibrous root systems. Soil in which there are many fibrous roots is protected from erosion. 3. Some tropical orchids that grow on trees have spongy roots.

All of us have had the experience of being thirsty at times, but can you imagine how it would feel to be thirsty for days? If a human being has absolutely nothing to drink for five to six days, he will die .  Feeling thirsty is simply our body's way of telling us to replenish its liquid supply. 1. The reason for this thirst is caused by a change in the salt content of our blood . 2. There is a certain normal amount of salt and water in our blood . 3. When this changes by having more salt in relation to water in our blood, thirst results. There is a part of our brain called the 'Thirst centre'(Hypothalamus) . It responds to the amount of salt in our blood. When there is a change, it sends messages to the back of the throat. From there, messages go to the brain, and it is this combination of feelings that makes us say we are thirsty. *Avoid eating too much of salt*

Antibiotics are chemicals . When these chemicals are put into the body they kill or stop the growth of certain kinds of germs. In other words they help your body to fight off disease. Many modern antibiotics are made from microbes, which are tiny living things . For example, bacteria and moulds are microbes. The microbes used in making antibiotics are chosen for their ability to produce chemicals that wage war on the microbes of disease. In simple terms this means that man is taking advantage of the struggle that goes on in nature among microbes. Antibiotics are very effective at curing diseases and work in various ways. One antibiotic may act in different ways against different germs . It may kill the germs in one case and in another only weaken them and let the body's natural defences take over.

Why does Mickey Mouse have three fingers and one thumb on each hand? In fact, why is virtually every cartoon animal's hand beset with one missing digit? Conversations with many cartoonists, animators and Disney employees confirm what we were at first sceptical about. Mickey Mouse has four fingers because it is convenient for the artists and animators who have drawn him.  In the early cartoons, each frame was hand-drawn by an animator painstaking and tedious work. No part of the human anatomy is harder to draw than a hand , and it is particularly difficult to draw distinct fingers without making the whole hand look disproportionately large . The artists who drew Mickey were more than happy to go along with any conceit that saved them some work. So in Disney and most other cartoons, the animals sport a thumb and three fingers, while humans, such as Snow White and Cinderella, are spared the amputation. And before you ask - no, we don't know f...

Many imponderables readers want to know the answer to this question. Perhaps the most complete explanation came from George B Kauffman. Sound is the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other mediums. Low-frequency sound is heard as low pitch and higher frequencies as correspondingly higher pitch. The frequency (pitch) of sound depends on the density of the medium through which the vibrations are transmitted; the less dense the medium, the greater the rate (frequency) of vibration, and hence the higher the pitch of the sound. The densities of gases are directly proportional to their molecular weights. Because the density of helium (mol. wt. 4) is much less than that of air, a mixture of about 78 percent nitrogen (mol. wt. 28) and about 20 percent oxygen (mol. wt. 32). The vocal cords vibrate much faster (at a higher frequency) in helium than in air, and therefore the voice is perceived as havi...

Dimples are a generic name for indentations of the skin. They are produced when muscle fibres are attached to the deep surface of the skin, such as in the cheek or chin , or where the skin is attached to bones by fibrous bands, such as the elbow, shoulder and back. Dimples are most likely to appear where the skin is most tightly attached to the underlying bone . Dr William Jollie, Professor and Chairman of Anatomy at the Medical College of Virginia, says ' dimples probably are due to some developmental fault in the connective tissue that binds skin to bone '. So those dimples we've long envied are actually an anatomical flaw! And the tendency towards dimples seems to be hereditary.

A lot of things can keep us healthy: A right amount of sleep, Exercise, Fresh air,  Having friends,  and Healthy food.  Eating healthy food means not eating too much and not eating the same thing  always. Our food is composed of three components: Fats, Carbohydrates, and Proteins. Carbohydrates like sugar and starch, are present in potatoes. We also need vitamins and minerals, such as salt or calcium, to stay healthy. * We need to brush our teeth often and keep ourselves clean to keep away the bacteria and remain healthy.

If we eat more than what we really need, our body converts the excess food into fat and we become bulky and heavy. The skeleton and the joints are not designed to carry too much continuous load; hence, at some point of time the back and the joints begin to ache.  Any kind of fast movement becomes tiring and strenuous for the heart and the circulatory system. We get out of breath very easily. Although it is difficult for them, they can get in shape again through training and healthy eating.

There is no transportation system in any city that can  compare in efficiency with the circulatory system of our  body.  If you can imagine two systems of pipes, one large and  one small, both meeting at a central pumping station, you  will have an idea of the circulatory system. The smaller pipes  go from the heart to the lungs and back, while the larger ones  from the heart to the various other parts of the body  These pipes are called arteries, veins and capillaries.  Arteries are vessels in which blood is carried away  from the heart. In veins, the blood is coming back to  the heart.  In general terms, arteries are carrying pure  blood to various parts of the body, and the veins are  bringing back blood loaded with waste products. The pumping station is of course the heart. Arteries lie deep in the tissues, except at the  wrist, over the instep, at the temple and along the...

Blood:   The blood which flows through our body contains many different materials and cells. Each part of the blood has its own special job to do. Plasma: The liquid part of our blood is called the plasma and makes up a little more than half the blood. It is light yellow in colour and thicker than water as many substances are dissolved in it. These substances are protein, antibodies that fight disease, fibrinogen that helps the blood to clot, carbohydrates, fats and salts, in addition to the blood cells themselves  RBC: The red cells (also called red blood corpuscles) give the blood its colour. There are so many of them in the blood that it makes it all look red. There are about 35 trillion of these tiny, round, flat discs moving around in your body all at once. As the young red cell grows and takes on adult form in the marrow, it loses its nucleus and builds up more and more haemoglobin. Haemoglobin:   Haemoglobin is the red pigment, or colour. ...