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Why Aquatic Animals have Streamlined Bodies?
Created on
12/29/2011
Aquatic animals have streamlined bodies that move through the water with the least possible resistance i.e. to reduce the effects of water resistance.
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Why Earthworms are called Friends of Farmers?
Created on
12/29/2011
The earthworm digs through the soil by eating it. The soil passes completely though the worm's system and out via the anus. Any bits of humus in the soil are digested. The earthworm cannot live in poor soil; it will starve. It's digging stirs, loosens, and aerates the soil, allowing water and air to enter. The earthworm improves and enriches the soil for plant roots, thus making the plants healthy.
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Why we should breathe from our Nose & not from the Mouth?
Created on
12/29/2011
Breathing through the nose has many benefits. Breathing through the mouth, many negatives. There are some researchers who believe that mouth breathing and associated hyperventilation causes or exacerbates asthma, high blood pressure, heart disease, and many other medical problems. It makes some folks look dull witted or slightly unconscious.
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Why Carbon Dioxide is used in Fire Extinguishers?
Created on
12/29/2011
CO2 extinguishers contain carbon dioxide, a non-flammable gas, and are highly pressurized. The pressure is so great that it is not uncommon for bits of dry ice to shoot out. CO2 is heavier than oxygen so these extinguishers work by displacing or taking away oxygen from the surrounding area. CO2 is also very cold so it also works by cooling the fuel.
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Why Nitrogen gas is used in packging of food?
Created on
12/29/2011
Nitrogen is an environmentally friendly substance. It is a chemically non-reactive, colorless and odorless gas that comprises 79% of the earth’s atmosphere. Many foods including snacks, coffee, meats, and bake goods experience increased shelf life by utilizing a packaging technique with nitrogen-rich atmosphere. This process uses gaseous nitrogen to displace the oxygen in sealed packages and, in turn prevents the growth of bacteria, which has a negative effect on freshness.
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What is the difference between Fats and Oils?
Created on
12/29/2011
The difference between fats and oils is in their melting point. Fats tend to be solids at room temperature; oils tend to be liquid at room temperature. To turn a fat into an oil, merely raise its temperature above its melting point.
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Why Spines are important for the survival of Cactus?
Created on
12/29/2011
Spines play a major role in producing the micro climate a cactus needs to survive. All plants have specialized means of working with the environment in which they grow to adjust that environment for survival and reproduction. In many plants, the leaves provide temperature-reducing shade that enables the roots to continue functioning. Other desert plants such as saltgrass, mesquite, and ocotillo reduce overall exposure to the sun by folding or dropping their leaves. Cactus evolved a different adaptation, converting their leaves to tough spines which won’t burn or wither and help shade the stem from the sun. It seems obvious to us humans that spines also protect the succulent cactus stems from being eaten by animals.
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Why Do We Breathe?
Created on
12/29/2011
Our body is made up of tiny cells, each of which has a special job that keeps you alive. Every cell in your body needs a special gas called oxygen, that allows the cell to get energy from the food you eat. Oxygen in the air is brought into our lungs. That's when our blood picks it up and brings it to your cells.
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Why Iron Rusts?
Created on
12/29/2011
Rusting is a chemical process that, can take place in metals exposed to the atmosphere. Not all metals however rust. Rusting is common with the metal, iron.
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Why Are Metals Called Lustrous?
Created on
12/29/2011
This is because visible lightwaves are not readily transmitted through the bulk of their microstructure. The large number of mobile electrons in any typical metallic solid (element or alloy) is responsible for the fact that they can never be categorized as transparent materials.
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