Monday, August 30, 2010
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Wednesday, August 4, 2010
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Biology is the branch of science that deals with the study of living organisms the term biology is derived from the combination of two greek words –‘bios’ that mens life and ‘logos’ that means knowledge Biology is also known as science of life. The term was introduced in Germany in 1800 and popularized by the French naturalist Jean-Baptiste de Lamarck as a means of encompassing the growing number of disciplines involved with the study of living forms. The unifying concept of biology received its greatest stimulus from the English zoologist Thomas Henry Huxley, who was also an important educator. Huxley insisted that the conventional segregation of zoology and botany was intellectually meaningless and that all living things should be studied in an integrated way. Huxley’s approach to the study of biology is even more cogent today, because scientists now realize that many lower organisms are neither plants nor animals. The limits of the science, however, have always been difficult to determine, and as the scope of biology has shifted over the years, its subject areas have been changed and reorganized. Today biology is subdivided into hierarchies based on the molecule, the cell, the organism, and the population.Biology is very vast and complex subjects and the scope of biology is very wide.Biology is the study of living organisms that includes plant ,animal and micro-animal. Hance basically it has three main branchs they are

1 Botany : Branch of biology that deals with the study of plants

2 Zoology: Branch of biology that deals with the study of Animals

3 Micro-Biology : Branch of biology that deals with the study of micro-orsanisms
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Gene is the basic unit of heredity found in the cells of all living organisms, from bacteria to humans. Genes determine the physical characteristics that an organism inherits, such as the shape of a tree’s leaf, the markings on a cat’s fur, and the color of a human hair .Genes are composed of segments of deoxyribonucleic acid (DNA), a molecule that forms the long, threadlike structures called chromosomes. The information encoded within the DNA structure of a gene directs the manufacture of proteins, molecular workhorses that carry out all life-supporting activities within a cell .Chromosomes within a cell occur in matched pairs. Each chromosome contains many genes, and each gene is located at a particular site on the chromosome, known as the locus. Like chromosomes, genes typically occur in pairs. A gene found on one chromosome in a pair usually has the same locus as another gene in the other chromosome of the pair, and these two genes are called alleles. Alleles are alternate forms of the same gene. For example, a pea plant has one gene that determines height, but that gene appears in more than one form—the gene that produces a short plant is an allele of the gene that produces a tall plant. The behavior of alleles and how they influence inherited traits follow predictable patterns. Austrian monk Gregor Mendel first identified these patterns in the 1860s .In organisms that use sexual reproduction, offspring inherit one-half of their genes from each parent and then mix the two sets of genes together. This produces new combinations of genes, so that each individual is unique but still possesses the same genes as its parents. As a result, sexual reproduction ensures that the basic characteristics of a particular species remain largely the same for generations. However, mutations, or alterations in DNA, occur constantly. They create variations in the genes that are inherited. Some mutations may be neutral, or silent, and do not affect the function of a protein. Occasionally a mutation may benefit or harm an organism and over the course of evolutionary time, these mutations serve the crucial role of providing organisms with previously nonexistent proteins. In this way, mutations are a driving force behind genetic diversity and the rise of new or more competitive species that are better able to adapt to changes, such as climate

Geneticists are scientists who study the function and behavior of genes. Since the 1970s geneticists have devised techniques, cumulatively known as genetic engineering, to alter or manipulate the DNA structure within genes. These techniques enable scientists to introduce one or more genes from one organism into a second organism. The second organism incorporates the new DNA into its own genetic material, thereby altering its own genetic characteristics by changing the types of proteins it can produce. In humans these techniques form the basis of gene therapy, a group of experimental procedures in which scientists try to substitute one or more healthy genes for defective ones in order to eliminate symptoms of disease.

Genetic engineering techniques have also enabled scientists to determine the chromosomal location and DNA structure of all the genes found within a variety of organisms. Scientists hope to use this genetic information to develop life-saving drugs for a variety of diseases, to improve agricultural crop yields.
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The branch of biology which deals with the  study of inter-relationship amonisms and interactions between animals and their enviriments is called ecosystem. An ecosystem is all the living and nonliving things in a certain area. All the plants and animals, even the microorganisms that live in the soil, are living parts of an ecosystem. Air, water, and rocks are nonliving parts of an ecosystem.Ecosystems are smaller parts of all the living environments on Earth. Earth’s entire living environment is called the biosphere. The biosphere is made up of large areas called biomes. Land biomes include grasslands, deserts, coniferous forests (forests of cone-bearing trees), deciduous forests (forests of trees that shed their leaves), and tropical rain forests. There are also biomes in bodies of water, such as the ocean.

The biomes, in turn, are made up of many ecosystems. The desert biome, for example, covers all the deserts of the world. Each individual desert is an ecosystem. The Mojave Desert in California is a desert ecosystem.

Some ecosystems are huge, and some are small. A tropical rain forest ecosystem might cover hundreds of square miles. A mangrove swamp ecosystem might stretch only a few miles along the shore of an island.A place can have more than one ecosystem. A rain forest and a mangrove swamp could be on the same island. A coral reef ecosystem might be in the water around the island.

What is echosystem works : The living portion of an ecosystem is best described in terms of feeding levels known as trophic levels. Green plants make up the first trophic level and are known as primary producers. Plants are able to convert energy from the sun into food in a process known as photosynthesis. In the second trophic level, the primary consumers—known as herbivores—are animals and insects that obtain their energy solely by eating the green plants. The third trophic level is composed of the secondary consumers, flesh-eating or carnivorous animals that feed on herbivores. At the fourth level are the tertiary consumers, carnivores that feed on other carnivores. Finally, the fifth trophic level consists of the decomposers, organisms such as fungi and bacteria that break down dead or dying matter into nutrients that can be used again.

Some or all of these trophic levels combine to form what is known as a food web, the ecosystem’s mechanism for circulating and recycling energy and materials. For example, in an aquatic ecosystem algae and other aquatic plants use sunlight to produce energy in the form of carbohydrates. Primary consumers such as insects and small fish may feed on some of this plant matter, and are in turn eaten by secondary consumers, such as salmon. A brown bear may play the role of the tertiary consumer by catching and eating salmon. Bacteria and fungi may then feed upon and decompose the salmon carcass left behind by the bear, enabling the valuable nonliving components of the ecosystem, such as chemical nutrients, to leach back into the soil and water, where they can be absorbed by the roots of plants. In this way nutrients and the energy that green plants derive from sunlight are efficiently transferred and recycled throughout the ecosystem.
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                            ORGANIC CHEMISTRY

Organic Chemistry is the branch of chemistry in which deals with the study of carbon compounds and their deravitives reactions. A wide variety of classes of substances—such as drugs, vitamins, plastics, natural and synthetic fibers, as well as carbohydrates, proteins, and fats—consist of organic molecules. Organic chemists determine the structures of organic molecules, study their various reactions, and develop procedures for the synthesis of organic compounds. Organic chemistry has had a profound effect on modern life: It has improved natural materials and it has synthesized natural and artificial materials that have, in turn, improved health, increased comfort, and added to the convenience of nearly every product manufactured today.

The advent of organic chemistry is often associated with the discovery in 1828 by the German chemist Friedrich Wöhler that the inorganic, or mineral, substance called ammonium cyanate could be converted in the laboratory to urea, an organic substance found in the urine of many animals. Before this discovery, chemists thought that intervention by a so-called life force was necessary for the synthesis of organic substances. Wöhler's experiment broke down the barrier between inorganic and organic substances. Modern chemists consider organic compounds to be those containing carbon and one or more other elements, most often hydrogen, oxygen, nitrogen, sulfur, or the halogens, but sometimes others as well

Sourses of organic chemistry
Coal tar was once the only source of aromatic and some heterocyclic compounds. Petroleum was the source of aliphatic compounds that contain such substances as gasoline, kerosene, and lubricating oil. Natural gas supplied methane and ethane. These three categories of natural substances are still the major sources of organic compounds for most countries. When petroleum is not available, however, a chemical industry can be based on acetylene, which in turn can be synthesized from limestone and coal. During World War II, Germany was forced into just that position when it was cut off from reliable petroleum and natural-gas sources.Table sugar from cane or beets is the most abundant pure chemical from a plant source. Other major substances derived from plants include carbohydrates such as starch and cellulose, alkaloids, caffeine, and amino acids. Animals feed on plants and other animals to synthesize amino acids, proteins, fats, and carbohydrates.
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The words Thermodynamics ‘Thermo’ means Heat and ‘Dynamics’ means study so that Thermodynamics is a branch  of physics that describes and correlates the physical properties of macroscopic systems of matter and energy. The principles of thermodynamics are of fundamental importance to all branches of science and engineering. A central concept of thermodynamics is that of the macroscopic system, defined as a geometrically isolable piece of matter in coexistence with an infinite, unperturbable environment. The state of a macroscopic system in equilibrium can be described in terms of such measurable properties as temperature, pressure, and volume, which are known as thermodynamic variables. Many other variables (such as density, specific heat, compressibility, and the coefficient of thermal expansion) can be identified and correlated, to produce a more complete description of an object and its relationship to its environment.

When a macroscopic system moves from one state of equilibrium to another, a thermodynamic process is said to take place. Some processes are reversible and others are irreversible. The laws of thermodynamics, discovered in the 19th century through painstaking experimentation, govern the nature of all thermodynamic processes and place limits on them. Mainly thermodynamic is classified into following types

Zeroth law of thermodynamics When two systems are in equilibrium, they share a certain property. This property can be measured and a definite numerical value ascribed to it. A consequence of this fact is the zeroth law of thermodynamics.

Frist law of Thermodynamics The first law of thermodynamics gives a precise definition of heat, another commonly used concept.

Seccond law of Thermodynamics The second law of thermodynamics gives a precise definition of a property called entropy.
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Diesel Engine Is a type of internal-combustion engine in which heat caused by air compression ignites the fuel. At the instant fuel is injected into a diesel engine’s combustion chambers, the air inside is hot enough to ignite the fuel on contact. Diesel engines, therefore, do not need spark plugs, which are required to ignite the air-fuel mixture in gasoline engines. Diesel engines burn a petroleum product similar to kerosene, jet fuel, and home heating oil.

Diesel engines are more efficient and less expensive to operate than gasoline-powered engines, partly because diesel fuel costs less. Diesels consume less fuel and emit fewer waste products. A disadvantage of the diesel engine is the production of sooty, smelly smoke, but modern diesels generally run cleaner and with less odor than older models.

German engineer Rudolf Diesel invented the diesel engine in the 1890s. The engines initially used powdered coal for fuel. By 1897 Diesel had built a compression-ignition engine that ran on kerosene.

Diesel engines were more efficient than the steam engines of the 1800s and became popular. They were also big and heavy, suitable mostly for the shipping and railroad industries. They are still the engines of choice for heavy transportation and industry. Most modern buses, trucks, trains and ships are powered by diesels. These engines have become popular in some automobiles as well.

Main parts of internal-combustion engine : The four-stroke internal-combustion engine is used in most cars and trucks powered by gasoline or diesel. This illustration shows the parts of the engine that make the four-stroke cycle work. The starter moves the crankshaft to begin the four-stroke cycle to produce power. In gasoline engines, the battery supplies power to the spark plugs. The carburetor and intake manifold supply air and fuel. In many modern cars, a computer controls the amount of fuel injected instead

How four-stroke Engines works The cylinders contain pistons that move up and down. In a gasoline engine, a spark plug ignites a compressed mix of gasoline and air inside each cylinder. In a diesel engine, the diesel and air ignite without a spark plug. The hot expanding gas pushes back the piston in the cylinder, creating the power stroke in the cycle and moving the crankshaft.

Frist stroke Intake of fule and air : In the first part of the cycle, the piston moves down. In a gasoline engine, this stroke draws in a mix of gasoline and air from the carburetor through the intake valve at the top of the cylinder. In a diesel engine, only air is drawn in.

Second stroke compression : In the second part of the cycle, the intake valve closes and the piston rises. In a gasoline engine, this compresses the mix of gasoline and air. In a diesel engine, the air is first compressed and diesel fuel is injected directly into the cylinder at the end of the compression.

Third stroke Combustion : Combustion occurs during the third stroke. In a gasoline engine, an electric spark from the spark plug ignites the compressed mix of gasoline and air. The resulting explosion pushes the piston back as the burning gas expands, turning the crankshaft. The motion of the piston transforms chemical energy in the fuel into mechanical energy.In a diesel engine, the mix of diesel and air ignites spontaneously because the air became much hotter when it was compressed.

Forth stroke Exhaust : The gases left by the burned fuel are pushed out of the cylinder as the piston rises again. An exhaust valve at the top of the cylinder opens to let the fumes escape. When the valve closes, the piston can move down to start the intake cycle again.

Forth-stoke cycle : Many improvements have been made to the four-stroke engine since its invention in the 19th century. Recent improvements include fuel injection in place of a carburetor system. A computer controls the exact amount of fuel sprayed into the cylinder for more power and better fuel efficiency, as well as smoother operation and reduced exhaust emissions.
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The branch of biology which deals with the concerned with the study of plants. Plants are now defined as multicellular organisms that carry out photosynthesis. Organisms that had previously been called plants, however, such as bacteria, algae, and fungi, continue to be the province of botany, because of their historical connection with the discipline and their many similarities to true plants, and because of the practicality of not fragmenting the study of organisms into too many separate fields. Botany is concerned with all aspects of the study of plants, from the smallest and simplest forms to the largest and most complex, from the study of all aspects of an individual plant to the complex interactions of all the different members of a complicated botanical community of plants with their environment and with animals Branch of botany is very wide some are folling

Algalogy : Study of Algae

Mycology : Study of Fungai

Zymology : Study of Yeast

Bryology : Study of Bryophytes

Bacteriology : Study of Bacteria

Virology : Study of Study Virus

Pomology : Study of Fruits

Olericulture : Study of vegeatables

Spermology : Study of Seed

Pedology : Study of Soil

Palynology : Study of pollen grain

Agrostology : Study of Grasses
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The  study of the composition, structure, properties, and interactions of matter. Chemistry is also called the central science, because its interests lie between those of physics (which focuses on single substances) and biology (which focuses on complicated life processes). Chemists have divided chemistry into a number of different branches. These branches are somewhat arbitrary and do not have sharply defined boundaries. They often overlap with each other or with other sciences, such as physics, geology, or biology. Chemistry has many branches some of them flowing are main branches

Inorganic chemistry is the study of the chemical nature of the elements and their compounds (except hydrocarbons—compounds composed of carbon and hydrogen).

Organic chemistry is the study of compounds consisting largely of hydrocarbons, which provide the parent material of all other organic compounds. Since carbon atoms can form rings and long branched chains, hundreds of thousands of carbon-based molecules exist. Organic compounds are of special importance, because they make up the majority of compounds in living organisms. Organic compounds form coal and petroleum. Organic chemists have learned how to convert raw materials from coal, petroleum, and grain into synthetic textiles, pesticides, dyes, drugs, plastics, and many other products.

Physical chemistry is fundamental to all chemistry and deals with the application of physical laws to chemical systems and chemical change. Much of physical chemistry is concerned with the role of energy in chemical reactions; this branch of physical chemistry is known as thermodynamics. Other major areas of study in physical chemistry are the rates and mechanisms of reactions, called chemical kinetics. A third area of physical chemistry studies molecular structure. Physical chemists study molecular structure by examining the spectrum of electromagnetic energy emitted by molecules and explain structure using principles of quantum mechanics

Biochemistry is the chemistry of living organisms and life processes. Even the simplest living thing is a complex chemical factory. Biochemists must have a detailed knowledge of organic chemistry. In some aspects of biochemistry, advanced physical chemistry is used, and biophysics and molecular biology are companion sciences.

Geochemistry is the application of chemistry (and, inevitably, physics) to processes taking place in the earth, such as mineral formation, the metamorphosis of rocks, and the formation and migration of petroleum.
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Physics, major science, dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces. Sometimes in modern physics a more sophisticated approach is taken that incorporates elements of the three areas it relates to the laws of symmetry and conservation, such as those pertaining to energy, momentum, charge, and parity. It is also related in chemistry,Biology .Physics is also closely related to the other natural sciences and, in a sense, encompasses them. Chemistry, for example, deals with the interaction of atoms to form molecules. Physics covers a wide range of fields. This below table provides a brief description of topics covered in the major areas of study.

Major Fields in Physics

Astronomy Properties of space; origin and evolution of galaxies, stars, and planetary systems; origin and evolution of the universe. Includes astrophysics and cosmology.

Atomic Physics Structure and properties of atoms.

Cryogenics Properties and behavior of matter at extremely low temperatures.

Electromagnetism Electric and magnetic force fields; behavior of electrically charged particles in electromagnetic fields; propagation of electromagnetic waves. Also known as electrodynamics.

Elementary Particle

Physics Properties of elementary particles such as electons, photons, etc. Also known as high energy physics.

Fluid Dynamics Properties and behavior of moving fluids and gases.

Geophysics Application of physics to the study of the earth. Includes atmospheric physics, meteorology, hydrology, oceanography, geomagnetism, seismology, and volcanology.

Mathematical Physics Application of mathematical techniques to problems in physics.

Mechanics Forces, interactions, and motions of material objects.

Molecular Physics Structure and properties of molecules.

Nuclear Physics Structure, properties, reactions, and evolution of atomic nuclei.

Optics Propagation of light, electromagnetic waves.

Plasma Physics Behavior of ionized (electrically charged) gases.

Quantum Physics Quantum nature of matter, energy, and light. Behavior of systems composed of small numbers of elementary particles.

Solid State Physics Physical properties of solid materials. Includes crystallography, semiconductors, superconductivity. Also known as condensed matter physics.

Statistical Mechanics Application of statistical methods to model the behavior of systems composed of many particles.

Thermodynamics Temperature and energy; heat flow; transformation of energy; phases of matter (solid, liquid, gas, plasma).
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The Science is the systematic study of anything that can be examined, tested, and verified. The word science is derived from the Latin word scire, meaning “to know.” From its early beginnings, science has developed into one of the greatest and most influential fields of human endeavor. Today different branches of science investigate almost everything that can be observed or detected, and science as a whole shapes the way we understand the universe, our planet, ourselves, and other living things. Today different branches of science some of them Physics ,Chimistry & Biology .

Science develops through objective analysis, instead of through personal belief. Knowledge gained in science accumulates as time goes by, building on work performed earlier. Some of this knowledge—such as our understanding of numbers—stretches back to the time of ancient civilizations, when scientific thought first began. Other scientific knowledge—such as our understanding of genes that cause cancer or of quarks (the smallest known building block of matter)—dates back less than 50 years. However, in all fields of science, old or new, researchers use the same systematic approach, known as the scientific method, to add to what is known.

During scientific investigations, scientists put together and compare new discoveries and existing knowledge. In most cases, new discoveries extend what is currently accepted, providing further evidence that existing ideas are correct. For example, in 1676 the English physicist Robert Hooke discovered that elastic objects, such as metal springs, stretch in proportion to the force that acts on them. Despite all the advances that have been made in physics since 1676, this simple law still holds true.Scientists utilize existing knowledge in new scientific investigations to predict how things will behave. For example, a scientist who knows the exact dimensions of a lens can predict how the lens will focus a beam of light. In the same way, by knowing the exact makeup and properties of two chemicals, a researcher can predict what will happen when they combine. Sometimes scientific predictions go much further by describing objects or events that are not yet known. An outstanding instance occurred in 1869, when the Russian chemist Dmitry Mendeleyev drew up a periodic table of the elements arranged to illustrate patterns of recurring chemical and physical properties. Mendeleyev used this table to predict the existence and describe the properties of several elements unknown in his day, and when the elements were discovered several years later, his predictions proved to be correct.

In science, important advances can also be made when current ideas are shown to be wrong. A classic case of this occurred early in the 20th century, when the German geologist Alfred Wegener suggested that the continents were at one time connected, a theory known as continental drift. At the time, most geologists discounted Wegener's ideas, because the Earth's crust seemed to be fixed. But following the discovery of plate tectonics in the 1960s, in which scientists found that the Earth’s crust is actually made of moving plates, continental drift became an important part of geology.

Through advances like these, scientific knowledge is constantly added to and refined. As a result, science gives us an ever more detailed insight into the way the world around us works.
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Tuesday, August 3, 2010