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Physics - Gravitation Introduction All celestial bodies those found in the universe attract each other and the force of attraction among these bodies is called as the  gravitational force . Universal Law of Gravitation Every object in the universe has the property to attract every other object with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them (see the image given below). F  = force of attraction between two the objects ‘A’ & ‘B’ M  = mass of ‘A’ m  = mass of ‘B’ d 2  = the square of the distance between ‘A’ & ‘B’ G  = is the constant of proportionality and is known as the universal gravitation constant. The SI unit of G is  N m 2  kg –2 . It is obtained by substituting the units of force, distance and mass (as given in the following equation − $$G = \frac{Fd^2}{M \times m}$$ Henry Cavendish had calculated the value of  ‘G’  as  6.6...

Physics - Friction Introduction Friction  is result of the irregularities on the two surfaces in contact of each other. The force of friction is dependent on the irregularities of the surface; if it is greater, then the friction will be greater and if it is smooth, then the friction will be lesser. Effectively, the friction is result of the  interlocking  of irregularities in the two surfaces. If the two surfaces (in contact) are pressed harder, then the force of friction will increase. On a frictionless surface, if an object starts moving, it would not stop ever; Without friction, it is not possible to construct a building. Friction produces heat; when a matchstick is rubbed against the rough surface, it catches fire. Substances Reducing Friction The substances that reduce friction are known as  lubricants . E.g. when oil, grease, or graphite is applied between the moving part of a machine, then it creates a thin layer; resultantly, moving surfaces do not directly r...

 Force and Pressure Introduction When an object is either pushed or a pulled is known as a force. Motion, generated in an object, is because of an action of a force. The applied force makes the table move in a given direction. The strength of a force is commonly expressed by the magnitude. Force also has direction; likewise, if the magnitude or direction changes, it directly affects the force. If the force is applied in the direction opposite to the direction of motion, then it results in a decrease in the speed of the object. If an object is in motion, then external force may change in the state or direction of motion of that object. The state of motion of an object is explained by its speed and the direction of motion. The state of  ‘rest’  of an object is considered to be the zero speed, as − An object cannot move by itself. An object cannot change its speed by itself. An object cannot change its direction by itself. An object cannot change by itself. A force may make ...

Fats Introduction Fat is a significant foodstuff for many forms of life. Fats serve structural as well as metabolic functions. The fats are molecules made up of glycerol and fatty acid. Fat is an organic compound of hydrogen, carbon, oxygen. Based on the number and bonding of the carbon atoms, fats and oils, are categorized in the aliphatic chain. fats and oil Functions of Fats Following are the major functions of Fats − Fat is a vital dietary requirement. The fat is usually the stored source of energy in the body that remained store beneath the skin. Fat acts a protective layer especially in the human body and provide protection. Some of the vitamins such as vitamin A, vitamin D, vitamin E, and vitamin K are fat-soluble, which means they can only be absorbed, digested, and transported in conjunction with the fats. Fats actively help in maintaining the healthy skin and hair. Fats insulate body organs against external shock. Fats also maintain body temperature. Fats promote healthy cell...

 Proteins proteins Introduction Proteins, which are basically biomolecules, play wide range of functions in the body of a living organism. Proteins are made up of tiny elements of different types of amino acids. A sequence of amino acid residues in a protein is known particularly by the sequence of a gene; gene is encoded in the genetic code. After formation, proteins exist for a fixed period of time and are then degraded and recycled. The proteins get recycled by the cell's machinery by the process of protein turnover. Most of the proteins contain linear polymers made up of series of up to 20 different L-α-amino acids. The amino acids in a polypeptide chain are connected by peptide bonds (see the image given below). The peptide bond, usually, has two resonance forms, which contribute some double-bond characters. Protein Structure Most of the proteins illustrate unique 3-dimensional structures (see image given below). protein enzyme combining However, proteins have not a rigid stru...

Carbohydrate Introduction Consisting of oxygen (O), carbon (C), and hydrogen (H), carbohydrate is a biological molecule. Carbohydrate is one of the essential elements for the living organisms, as it plays various important roles. carbohydrates Carbohydrate is the main source of energy, as about two-third energy requirement of living beings is fulfilled by it. Glucose, sugar, and starch are the important examples of carbohydrate. Source of Carbohydrate Carbohydrates naturally are occurring in wide variety of foods, such as − Wheat Maize Rice Potatoes Sugarcane Fruits Table sugar Bread Milk Sugar that we eat in our everyday life is mainly sucrose (table sugar). Sucrose is added in many food items while preparing, e.g. jam, biscuits, cakes, energy drinks, etc. Further, many fruits naturally contain glucose and fructose. Glycogen is another type of carbohydrate that found in the liver and muscle. Cellulose found in the cell wall of plant cells is carbohydrate. Types of Carbohydrate The fol...

 Branches of Biology branches of biology The following table illustrates the different branches of biology with their brief description − Branch Studies Anatomy Study of the internal structure of an organism Aerobiology Study of airborne microorganisms Agronomy Study of soil management and crop production Agrostology Study of grasses Araneology Study of spiders Actinobiology Study of the effects of radiation upon living organisms Angiology Study of the diseases of the circulatory system and of the lymphatic system Bioinformatics of collecting and analyzing complex biological data including genetic codes through computer technology Biotechnology Use of cellular and biomolecular processes to develop technologies and products, which ultimately help to improve human lives and the health of the planet. Biochemistry Study of chemical and physio-chemical processes and substances, which occur within the living organisms. Batrachology Study of amphibians including frogs and toads Bioclimato...

Blood Group Introduction Based on the presence and absence of antibodies, the blood is classified into different groups. Further, while classification, the presence and absence of the inherited antigenic substances also considered. different blood groups The types of blood groups are inherited and represent contributions from both the father and the mother. ABO Blood Group System In human blood, usually, there are two antigens and antibodies. The two antigens are antigen A and antigen B. The two antibodies are antibody A and antibody B. The antigens are remaining in the red blood cells, whereas the antibodies are found in the serum. Based on the antigen property, the blood group of all human beings can be classified as − Blood Group A  − antigen A and antibody B Blood Group B  − antigen B and antibody A Blood Group AB  − antigen A and antigen B and no antibody Blood Group O  − no antigen, but antigen A as well as antibody B Consideration of the ABO system is the most...

some brain facts  

WEIRD SCIENCE FACTS FOR YOU okay you have studied a lot and is time to take some break with some amazing facts. hope you enjoy yourself. Today i started adding image facts  to our website because i have observed that student perform better when they take a break from studies and do something abstract   OXYGEN BRAIN SURGERY  

Natural Resources Introduction The resources, available on the Earth and the energy being received from the Sun, are essential to meet the basic necessities of all life-forms on the Earth. The  biotic  component incorporates all living of the biosphere. human sperm cells The abiotic component incorporates the air, the water, and the soil of the biosphere. Biogeochemical Cycles Biogeochemical cycles explain a constant interaction between the biotic and abiotic components of the biosphere. Biogeochemical cycles are a dynamic phenomenon that helps to maintain the stability in the ecosystem. The significant biogeochemical cycles are − Water Cycle Carbon Cycle Nitrogen Cycle Oxygen Cycle Let’s discuss each of them in brief − Water Cycle The whole process, starting from the water evaporation, rainfall to flowing back into the sea via rivers, is known as the  water-cycle . water forming a circle As shown in the image given above, water cycle is a complex phenomenon. During the p...

Biology - Why do We Fall Ill Introduction Health means a state of mental, physical, and social well-being. The health of an organism largely depends on his/her surroundings or the environment. a sick man Major causes of poor health are - the garbage, which is thrown in an open area nearby residence or streets, or/and the open drain water lying stagnant around the residence area. The public cleanliness is the key of good health. Some diseases, last only for a short period of time, are known as  acute diseases . E.g. cold, fever, etc. The diseases that last for a long period of time, even as much as a lifetime, are known as  chronic diseases . E.g. asthma, osteoporosis, etc. Chronic diseases, normally, have very severe long-term effects on people’s health as compared to the acute diseases. Infectious Diseases When microbes are the immediate causes of a disease, it is known as  infectious diseases . Some of the major agents of infectious diseases are viruses, bacteria, fungi...

Microorganisms: Friend and Foe Introduction The living organisms (available around us), which we cannot see with our naked eyes, are known as  microorganisms  or  microbes . Microorganisms are classified into the following four major groups − Bacteria Fungi Protozoa Algae Viruses Viruses are also microscopic microorganism. Viruses get reproduced only inside the cells of the host organism, which may be a bacterium, plant, or animal. The common ailments, such as cold, influenza (flu), and coughs are caused by viruses. The serious diseases, such as polio and chicken pox are also caused by viruses. The diseases like dysentery and malaria are caused by protozoans. The diseases like typhoid and tuberculosis (TB) are caused by bacteria. The single celled microorganisms are known as bacteria, algae, and protozoa. The multicellular microorganisms are known as fungi and algae. The microorganism can survive in any type of environment ranging from ice cold to hot desert. Microorganis...

Biology - Respiration Introduction The food material, taken in during the process of nutrition, is used by cells and then they provide energy for various life processes. Some organisms use oxygen to break-down glucose completely into carbon dioxide and water, such processes normally take place in cytoplasm. The following diagram illustrates the whole process of break-down of glucose through various pathways − During cellular respiration, the energy released, is immediately used to synthesize a molecule known as  ATP . ATP is further used to fuel all other activities in the cell. However, in these processes, ATP is broken down and give rise to a fixed amount of energy. This energy usually drives the endothermic reactions taking place in the cell. Adenosine triphosphate or simply ATP is a small molecule used in cells as a coenzyme (see image given below). More often, ATP is referred as the  energy currency  for most of the cellular processes (especially intracellular energy...

 Life Processes Introduction The processes, which collectively perform the maintenance of our body system, are known as  life processes . The maintenance processes protect us from damage and break-down; however, to keep these maintenance processes working properly, we need to provide energy to them. Healthy food is the best source of such energy. Nutrition We need energy from outside in order to grow, develop, synthesize protein, and other substances. The ultimate source of energy is varieties of healthy foods. These foods provide us nutrition essential for our survival. Depending upon the sources, nutrition is categorized as Autotrophic Nutrition and Heterotrophic Nutrition. Autotrophic Nutrition The autotrophic nutrition is prepared through the process of photosynthesis. Photosynthesis is a process by which autotrophic organisms (green plants) take in substances from the outside and then convert them into stored forms of energy. During the process of photosynthesis, carbon d...

Heredity and Evolution Introduction evolution The principle of heredity determines the process by which traits and characteristics of an organism are reliably inherited. There are some organisms (especially plants) in which there are very less variations and sometimes difficult to establish the differences, but in some other organisms (especially human beings), there are comparatively greater variations. This is the reason that offspring do not look similar. Rules for the Inheritance of Traits – Mendel’s Contributions Johann Mendel is known as " father of modern genetics ." In human beings, the rules for inheritance of traits and characteristics are related to the fact that both the father and the mother equally contribute the genetic material to their child. Further, each trait of an offspring is usually influenced by both paternal and maternal DNA. Johann Mendel, who was an Austrian scientist, had experimented on peas and gave the “ laws of inheritance .” Mendel used a vari...

Reaching the Age of Adolescence Introduction girl smilling The phase of life, when the body undergoes radical changes, leading to reproductive maturity, is known as  adolescence . Adolescence normally begins around the age of 11 and lasts up to 18 or 19 years of the age. However, the phase of adolescence varies from person to person. Starting from thirteen (13) to nineteen (19), ‘teen’ is suffix and common in every number; therefore, adolescents are also known as ‘ teenagers .’ In girls, adolescence phase may begin one year or two years earlier than the boys. During the adolescence phase, the human body undergoes several changes, which are marked as the onset of  puberty . The most important change, which marks puberty, is that the boys and the girls become capable of reproduction. Puberty, however, ends when an adolescent phase attains reproductive maturity. Changes at Puberty The most conspicuous change during the puberty is the swift increase in height. In the beginning, gi...